1
|
Shipp S. Computational components of visual predictive coding circuitry. Front Neural Circuits 2024; 17:1254009. [PMID: 38259953 PMCID: PMC10800426 DOI: 10.3389/fncir.2023.1254009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/13/2023] [Indexed: 01/24/2024] Open
Abstract
If a full visual percept can be said to be a 'hypothesis', so too can a neural 'prediction' - although the latter addresses one particular component of image content (such as 3-dimensional organisation, the interplay between lighting and surface colour, the future trajectory of moving objects, and so on). And, because processing is hierarchical, predictions generated at one level are conveyed in a backward direction to a lower level, seeking to predict, in fact, the neural activity at that prior stage of processing, and learning from errors signalled in the opposite direction. This is the essence of 'predictive coding', at once an algorithm for information processing and a theoretical basis for the nature of operations performed by the cerebral cortex. Neural models for the implementation of predictive coding invoke specific functional classes of neuron for generating, transmitting and receiving predictions, and for producing reciprocal error signals. Also a third general class, 'precision' neurons, tasked with regulating the magnitude of error signals contingent upon the confidence placed upon the prediction, i.e., the reliability and behavioural utility of the sensory data that it predicts. So, what is the ultimate source of a 'prediction'? The answer is multifactorial: knowledge of the current environmental context and the immediate past, allied to memory and lifetime experience of the way of the world, doubtless fine-tuned by evolutionary history too. There are, in consequence, numerous potential avenues for experimenters seeking to manipulate subjects' expectation, and examine the neural signals elicited by surprising, and less surprising visual stimuli. This review focuses upon the predictive physiology of mouse and monkey visual cortex, summarising and commenting on evidence to date, and placing it in the context of the broader field. It is concluded that predictive coding has a firm grounding in basic neuroscience and that, unsurprisingly, there remains much to learn.
Collapse
Affiliation(s)
- Stewart Shipp
- Institute of Ophthalmology, University College London, London, United Kingdom
| |
Collapse
|
2
|
Overview of (f)MRI Studies of Cognitive Aging for Non-Experts: Looking through the Lens of Neuroimaging. Life (Basel) 2022; 12:life12030416. [PMID: 35330167 PMCID: PMC8953678 DOI: 10.3390/life12030416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 02/21/2022] [Accepted: 03/11/2022] [Indexed: 11/20/2022] Open
Abstract
This special issue concerning Brain Functional and Structural Connectivity and Cognition aims to expand our understanding of brain connectivity. Herein, I review related topics including the principle and concepts of functional MRI, brain activation, and functional/structural connectivity in aging for uninitiated readers. Visuospatial attention, one of the well-studied functions in aging, is discussed from the perspective of neuroimaging.
Collapse
|
3
|
Salkoff DB, Zagha E, McCarthy E, McCormick DA. Movement and Performance Explain Widespread Cortical Activity in a Visual Detection Task. Cereb Cortex 2021; 30:421-437. [PMID: 31711133 DOI: 10.1093/cercor/bhz206] [Citation(s) in RCA: 93] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 08/12/2019] [Accepted: 08/14/2019] [Indexed: 11/14/2022] Open
Abstract
Recent studies in mice reveal widespread cortical signals during task performance; however, the various task-related and task-independent processes underlying this activity are incompletely understood. Here, we recorded wide-field neural activity, as revealed by GCaMP6s, from dorsal cortex while simultaneously monitoring orofacial movements, walking, and arousal (pupil diameter) of head-fixed mice performing a Go/NoGo visual detection task and examined the ability of task performance and spontaneous or task-related movements to predict cortical activity. A linear model was able to explain a significant fraction (33-55% of variance) of widefield dorsal cortical activity, with the largest factors being movements (facial, walk, eye), response choice (hit, miss, false alarm), and arousal and indicate that a significant fraction of trial-to-trial variability arises from both spontaneous and task-related changes in state (e.g., movements, arousal). Importantly, secondary motor cortex was highly correlated with lick rate, critical for optimal task performance (high d'), and was the first region to significantly predict the lick response on target trials. These findings suggest that secondary motor cortex is critically involved in the decision and performance of learned movements and indicate that a significant fraction of trial-to-trial variation in cortical activity results from spontaneous and task-related movements and variations in behavioral/arousal state.
Collapse
Affiliation(s)
- David B Salkoff
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA
| | - Edward Zagha
- Department of Psychology, University of California Riverside, Riverside, CA 92521, USA
| | - Erin McCarthy
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - David A McCormick
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510, USA.,Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| |
Collapse
|
4
|
Avila E, Lakshminarasimhan KJ, DeAngelis GC, Angelaki DE. Visual and Vestibular Selectivity for Self-Motion in Macaque Posterior Parietal Area 7a. Cereb Cortex 2020; 29:3932-3947. [PMID: 30365011 DOI: 10.1093/cercor/bhy272] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 09/05/2018] [Indexed: 01/12/2023] Open
Abstract
We examined the responses of neurons in posterior parietal area 7a to passive rotational and translational self-motion stimuli, while systematically varying the speed of visually simulated (optic flow cues) or actual (vestibular cues) self-motion. Contrary to a general belief that responses in area 7a are predominantly visual, we found evidence for a vestibular dominance in self-motion processing. Only a small fraction of neurons showed multisensory convergence of visual/vestibular and linear/angular self-motion cues. These findings suggest possibly independent neuronal population codes for visual versus vestibular and linear versus angular self-motion. Neural responses scaled with self-motion magnitude (i.e., speed) but temporal dynamics were diverse across the population. Analyses of laminar recordings showed a strong distance-dependent decrease for correlations in stimulus-induced (signal correlation) and stimulus-independent (noise correlation) components of spike-count variability, supporting the notion that neurons are spatially clustered with respect to their sensory representation of motion. Single-unit and multiunit response patterns were also correlated, but no other systematic dependencies on cortical layers or columns were observed. These findings describe a likely independent multimodal neural code for linear and angular self-motion in a posterior parietal area of the macaque brain that is connected to the hippocampal formation.
Collapse
Affiliation(s)
- Eric Avila
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
| | | | - Gregory C DeAngelis
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, NY, USA
| | - Dora E Angelaki
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA.,Department of Electrical and Computer Engineering, Rice University, Houston, TX, USA
| |
Collapse
|
5
|
Lin Z, Miao C, Zhang Y. Human electrophysiology reveals delayed but enhanced selection in inhibition of return. Cognition 2020; 205:104462. [PMID: 32979631 DOI: 10.1016/j.cognition.2020.104462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 09/05/2020] [Accepted: 09/07/2020] [Indexed: 11/28/2022]
Abstract
Visual environment tends to be stable over the short run. An immediately visited location often doesn't provide new information and can be safely inhibited, as exemplified by inhibition of return (IOR)-attention takes longer to return to a previously cued location. Attention selection at this inhibited location has been widely characterized as inferior, in which the target at the cued location has diminished salience, with lower rate of accumulation in the priority map for attention selection. We demonstrate here that an electrophysiology index of visual selection-the N2pc component-is delayed but enhanced at the cued than uncued location, and this enhancement in the N2pc amplitude predicts reduction in the behavioral IOR effect. By isolating a pure target N2pc, these results reveal an active attention enhancement mechanism that facilitates adaptive allocation of attention when a target appears at a previously cued location, potentially acting as a compensation mechanism for inhibition.
Collapse
Affiliation(s)
- Zhicheng Lin
- Department of Psychology, Soochow University, Suzhou, Jiangsu 215000, China; Applied Psychology Program, The Chinese University of Hong Kong, Shenzhen 518172, China
| | - Chengguo Miao
- Department of Psychology, Soochow University, Suzhou, Jiangsu 215000, China
| | - Yang Zhang
- Department of Psychology, Soochow University, Suzhou, Jiangsu 215000, China.
| |
Collapse
|
6
|
Kasten FH, Wendeln T, Stecher HI, Herrmann CS. Hemisphere-specific, differential effects of lateralized, occipital-parietal α- versus γ-tACS on endogenous but not exogenous visual-spatial attention. Sci Rep 2020; 10:12270. [PMID: 32703961 PMCID: PMC7378174 DOI: 10.1038/s41598-020-68992-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 05/28/2020] [Indexed: 11/09/2022] Open
Abstract
Orienting spatial attention has been associated with interhemispheric asymmetry of power in the α- and γ-band. Specifically, increased α-power has been linked to the inhibition of unattended sensory streams (e.g. the unattended visual field), while increased γ-power is associated with active sensory processing. Here, we aimed to differentially modulate endogenous and exogenous visual-spatial attention using transcranial alternating current stimulation (tACS). In a single-blind, within-subject design, participants performed several blocks of a spatial cueing task comprised of endogenous and exogenous cues while receiving lateralized α- or γ-tACS or no stimulation over left or right occipital-parietal areas. We found a significant, differential effect of α- and γ-tACS on endogenous (top-down) spatial attention but not on exogenous (bottom-up) attention. The effect was specific to tACS applied to the left hemisphere and driven by a modulation of attentional disengagement and re-orientation as measured during invalid trials. Our results indicate a causal role of α-/γ-oscillations for top-down (endogenous) attention. They may further suggest a left hemispheric dominance in controlling interhemispheric α-/γ-power asymmetry. The absence of an effect on exogenous attention may be indicative of a differential role of α-/γ-oscillations during different attention types or spatially distinct attentional subsystems.
Collapse
Affiliation(s)
- Florian H Kasten
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing for All", European Medical School, Carl Von Ossietzky University, Ammerlaender Heerstr. 114-118, 26129, Oldenburg, Germany
- Neuroimaging Unit, European Medical School, Carl Von Ossietzky University, Oldenburg, Germany
| | - Tea Wendeln
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing for All", European Medical School, Carl Von Ossietzky University, Ammerlaender Heerstr. 114-118, 26129, Oldenburg, Germany
| | - Heiko I Stecher
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing for All", European Medical School, Carl Von Ossietzky University, Ammerlaender Heerstr. 114-118, 26129, Oldenburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, Cluster for Excellence "Hearing for All", European Medical School, Carl Von Ossietzky University, Ammerlaender Heerstr. 114-118, 26129, Oldenburg, Germany.
- Neuroimaging Unit, European Medical School, Carl Von Ossietzky University, Oldenburg, Germany.
- Research Center Neurosensory Science, Carl Von Ossietzky University, Oldenburg, Germany.
| |
Collapse
|
7
|
Doricchi F, Pellegrino M, Marson F, Pinto M, Caratelli L, Cestari V, Rossi-Arnaud C, Lasaponara S. Deconstructing Reorienting of Attention: Cue Predictiveness Modulates the Inhibition of the No-target Side and the Hemispheric Distribution of the P1 Response to Invalid Targets. J Cogn Neurosci 2020; 32:1046-1060. [DOI: 10.1162/jocn_a_01534] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Orienting of attention produces a “sensory gain” in the processing of visual targets at attended locations and an increase in the amplitude of target-related P1 and N1 ERPs. P1 marks gain reduction at unattended locations; N1 marks gain enhancement at attended ones. Lateral targets that are preceded by valid cues also evoke a larger P1 over the hemisphere contralateral to the no-target side, which reflects inhibition of this side of space [Slagter, H. A., Prinssen, S., Reteig, L. C., & Mazaheri, A. Facilitation and inhibition in attention: Functional dissociation of pre-stimulus alpha activity, P1, and N1 components. Neuroimage, 125, 25–35, 2016]. To clarify the relationships among cue predictiveness, sensory gain, and the inhibitory P1 response, we compared cue- and target-related ERPs among valid, neutral, and invalid trials with predictive (80% valid/20% invalid) or nonpredictive (50% valid/50% invalid) directional cues. Preparatory facilitation over the visual cortex contralateral to the cued side of space (lateral directing attention positivity component) was reduced during nonpredictive cueing. With predictive cues, the target-related inhibitory P1 was larger over the hemisphere contralateral to the no-target side not only in response to valid but also in response to neutral and invalid targets: This result highlights a default inhibitory hemispheric asymmetry that is independent from cued orienting of attention. With nonpredictive cues, valid targets reduced the amplitude of the inhibitory P1 over the hemisphere contralateral to the no-target side whereas invalid targets enhanced the amplitude of the same inhibitory component. Enhanced inhibition was matched with speeded reorienting to invalid targets and drop in attentional costs. These findings show that reorienting of attention is modulated by the combination of cue-related facilitatory and target-related inhibitory activity.
Collapse
Affiliation(s)
- Fabrizio Doricchi
- Università degli Studi di Roma “La Sapienza”
- Fondazione Santa Lucia IRCCS, Rome, Italy
| | - Michele Pellegrino
- Università degli Studi di Roma “La Sapienza”
- Fondazione Santa Lucia IRCCS, Rome, Italy
| | | | - Mario Pinto
- Università degli Studi di Roma “La Sapienza”
- Fondazione Santa Lucia IRCCS, Rome, Italy
| | | | | | | | - Stefano Lasaponara
- Fondazione Santa Lucia IRCCS, Rome, Italy
- Libera Università Maria Santissima Assunta, Rome, Italy
| |
Collapse
|
8
|
Seidel Malkinson T, Bartolomeo P. Fronto-parietal organization for response times in inhibition of return: The FORTIOR model. Cortex 2018; 102:176-192. [DOI: 10.1016/j.cortex.2017.11.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 09/10/2017] [Accepted: 11/07/2017] [Indexed: 10/18/2022]
|
9
|
Abstract
Human volitional orienting is typically assessed using Posner's endogenous cuing task. As a volitional process, the literature has long emphasized the role of neocortical structures in this higher cognitive function. Based on recent data, we explored the possibility that subcortical channels may have a functional role in volitional orienting as measured by a Posner cuing task in which a nonspatial feature of a centrally presented cue is predictively related to the location of the target. In addition, we have compared this typical cuing task to a "purer" version, which does not involve the probability manipulation. A sensitive behavioral method was used to probe the contribution of monocular channels (mostly subcortical) in the two types of endogenous orienting tasks. In both tasks, a spatially informative cue and its ensuing target were presented to the same or different eyes at varying cue-target intervals. In the typically used endogenous task, the onset of facilitation was apparent earlier when the cue and target were presented to the same eye. In contrast, in the "pure" task no difference was found between the two eye-of-origin conditions. These data support the notion that endogenous facilitation, as measured in the typical Posner cuing task, involves lower monocular regions. Hence, in the typical endogenous task, which was developed to explore "volitional" orienting, a simple associative learning mechanism might elicit monocular, rapid orienting responses. Notably, the typical volitional orienting paradigm might be contaminated by simple contingency benefits and thus may not provide a pure measure of volitional processes.
Collapse
|
10
|
Abstract
In natural behavior, animals have access to multiple sources of information, but only a few of these sources are relevant for learning and actions. Beyond choosing an appropriate action, making good decisions entails the ability to choose the relevant information, but fundamental questions remain about the brain's information sampling policies. Recent studies described the neural correlates of seeking information about a reward, but it remains unknown whether, and how, neurons encode choices of instrumental information, in contexts in which the information guides subsequent actions. Here we show that parietal cortical neurons involved in oculomotor decisions encode, before an information sampling saccade, the reduction in uncertainty that the saccade is expected to bring for a subsequent action. These responses were distinct from the neurons' visual and saccadic modulations and from signals of expected reward or reward prediction errors. Therefore, even in an instrumental context when information and reward gains are closely correlated, individual cells encode decision variables that are based on informational factors and can guide the active sampling of action-relevant cues.
Collapse
|
11
|
Yoshida M, Hafed ZM, Isa T. Informative Cues Facilitate Saccadic Localization in Blindsight Monkeys. Front Syst Neurosci 2017; 11:5. [PMID: 28239342 PMCID: PMC5300996 DOI: 10.3389/fnsys.2017.00005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/30/2017] [Indexed: 11/13/2022] Open
Abstract
Patients with damage to the primary visual cortex (V1) demonstrate residual visual performance during laboratory tasks despite denying having a conscious percept. The mechanisms behind such performance, often called blindsight, are not fully understood, but the use of surgically-induced unilateral V1 lesions in macaque monkeys provides a useful animal model for exploring such mechanisms. For example, V1-lesioned monkeys localize stimuli in a forced-choice condition while at the same time failing to report awareness of identical stimuli in a yes-no detection condition, similar to human patients. Moreover, residual cognitive processes, including saliency-guided eye movements, bottom-up attention with peripheral non-informative cues, and spatial short-term memory, have all been demonstrated in these animals. Here we examined whether post-lesion residual visuomotor processing can be modulated by top-down task knowledge. We tested two V1-lesioned monkeys with a visually guided saccade task in which we provided an informative foveal pre-cue about upcoming target location. Our monkeys fixated while we presented a leftward or rightward arrow (serving as a pre-cue) superimposed on the fixation point (FP). After various cue-target onset asynchronies (CTOAs), a saccadic target (of variable contrast across trials) was presented either in the affected (contra-lesional) or seeing (ipsi-lesional) hemifield. Critically, target location was in the same hemifield that the arrow pre-cue pointed towards in 80% of the trials (valid-cue trials), making the cue highly useful for task performance. In both monkeys, correct saccade reaction times were shorter during valid than invalid trials. Moreover, in one monkey, the ratio of correct saccades towards the affected hemifield was higher during valid than invalid trials. We replicated both reaction time and correct ratio effects in the same monkey using a symbolic color cue. These results suggest that V1-lesion monkeys can use informative cues to localize stimuli in the contra-lesional hemifield, consistent with reports of a human blindsight subject being able to direct attention in cueing paradigms. Because the superior colliculus (SC) may contribute to residual visual capabilities after V1 lesions, and because this structure is important for controlling attentional resources, we hypothesize that our results reflect, among others, SC involvement in integrating top-down task knowledge for guiding orienting behavior.
Collapse
Affiliation(s)
- Masatoshi Yoshida
- Department of System Neuroscience, National Institute for Physiological SciencesOkazaki, Japan; School of Life Science, The Graduate University for Advanced StudiesHayama, Japan
| | - Ziad M Hafed
- Werner Reichardt Centre for Integrative Neuroscience, University of Tübingen Tübingen, Germany
| | - Tadashi Isa
- Department of Neuroscience, Kyoto University Graduate School of Medicine and Faculty of Medicine Kyoto, Japan
| |
Collapse
|
12
|
Berman RA, Cavanaugh J, McAlonan K, Wurtz RH. A circuit for saccadic suppression in the primate brain. J Neurophysiol 2016; 117:1720-1735. [PMID: 28003409 DOI: 10.1152/jn.00679.2016] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/21/2016] [Accepted: 12/21/2016] [Indexed: 01/06/2023] Open
Abstract
Saccades should cause us to see a blur as the eyes sweep across a visual scene. Specific brain mechanisms prevent this by producing suppression during saccades. Neuronal correlates of such suppression were first established in the visual superficial layers of the superior colliculus (SC) and subsequently have been observed in cortical visual areas, including the middle temporal visual area (MT). In this study, we investigated suppression in a recently identified circuit linking visual SC (SCs) to MT through the inferior pulvinar (PI). We examined responses to visual stimuli presented just before saccades to reveal a neuronal correlate of suppression driven by a copy of the saccade command, referred to as a corollary discharge. We found that visual responses were similarly suppressed in SCs, PI, and MT. Within each region, suppression of visual responses occurred with saccades into both visual hemifields, but only in the contralateral hemifield did this suppression consistently begin before the saccade (~100 ms). The consistency of the signal along the circuit led us to hypothesize that the suppression in MT was influenced by input from the SC. We tested this hypothesis in one monkey by inactivating neurons within the SC and found evidence that suppression in MT depends on corollary discharge signals from motor SC (SCi). Combining these results with recent findings in rodents, we propose a complete circuit originating with corollary discharge signals in SCi that produces suppression in visual SCs, PI, and ultimately, MT cortex.NEW & NOTEWORTHY A fundamental puzzle in visual neuroscience is that we frequently make rapid eye movements (saccades) but seldom perceive the visual blur accompanying each movement. We investigated neuronal correlates of this saccadic suppression by recording from and perturbing a recently identified circuit from brainstem to cortex. We found suppression at each stage, with evidence that it was driven by an internally generated signal. We conclude that this circuit contributes to neuronal suppression of visual signals during eye movements.
Collapse
Affiliation(s)
- Rebecca A Berman
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - James Cavanaugh
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Kerry McAlonan
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Robert H Wurtz
- Laboratory of Sensorimotor Research, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
13
|
Tanaka Y, Shimojo S. Temporal and Spatial Characteristics of Attention to Facilitate Manual and Eye-Movement Responses. Perception 2016; 30:283-302. [PMID: 11374201 DOI: 10.1068/p2587b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Previous investigation found that the speed of saccadic eye movements is enhanced when a temporal interval (gap) is introduced between the disappearance of a foveal fixation mark and the appearance of a peripheral target (the gap paradigm). Attention was shown to be involved in the gap paradigm. Here, we investigated relevant temporal and spatial characteristics of attention, manipulating central fixation marks and peripheral targets. Results from three experiments indicate that (i) the speed of manual and eye-movement detection is accelerated when a fixation mark changes abruptly (in less than 100 ms) before its termination in the gap paradigm; (ii) the speed is further accelerated when a peripheral target location is pre-cued; (iii) sufficient time for fixation (1000 ms) is necessary for the facilitation. These results suggest that fast and transient attention at the fixation spot facilitates attentional disengagement process that urges a spatial-orienting mechanism. Sustained attention is required in the engagement process during the fixation.
Collapse
Affiliation(s)
- Y Tanaka
- Department of Neurobiology, Brain Research, Weizmann Institute of Science, Rehovot 76100, Israel
| | | |
Collapse
|
14
|
Norton DJ, Nguyen VA, Lewis MF, Reynolds GO, Somers DC, Cronin-Golomb A. Visuospatial Attention to Single and Multiple Objects Is Independently Impaired in Parkinson's Disease. PLoS One 2016; 11:e0150013. [PMID: 26963388 PMCID: PMC4786138 DOI: 10.1371/journal.pone.0150013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Accepted: 02/08/2016] [Indexed: 11/29/2022] Open
Abstract
Parkinson’s disease (PD) is associated with deficits in visuospatial attention. It is as yet unknown whether these attentional deficits begin at a perceptual level or instead reflect disruptions in oculomotor or higher-order processes. In the present study, non-demented individuals with PD and matched normal control adults (NC) participated in two tasks requiring sustained visuospatial attention, both based on a multiple object tracking paradigm. Eye tracking was used to ensure central fixation. In Experiment 1 (26 PD, 21 NC), a pair of identical red dots (one target, one distractor) rotated randomly for three seconds at varied speeds. The task was to maintain the identity of the sole target, which was labeled prior to each trial. PD were less accurate than NC overall (p = .049). When considering only trials where fixation was maintained, however, there was no significant group difference, suggesting that the deficit’s origin is closely related to oculomotor processing. To determine whether PD had additional impairment in multifocal attention, in Experiment 2 (25 PD, 15 NC), two targets were presented along with distractors at a moderate speed, along with a control condition in which dots remained stationary. PD were less accurate than NC for moving (p = 0.02) but not stationary targets. This group difference remained significant when considering only trials where fixation was maintained, suggesting the source of the PD deficit was independent from oculomotor processing. Taken together, the results implicate separate mechanisms for single vs. multiple object tracking deficits in PD.
Collapse
Affiliation(s)
- Daniel J. Norton
- Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail:
| | - Victoria A. Nguyen
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Michaela F. Lewis
- Department of Neuroscience, Brown University, Providence, Rhode Island, United States of America
| | - Gretchen O. Reynolds
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - David C. Somers
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| | - Alice Cronin-Golomb
- Department of Psychological and Brain Sciences, Boston University, Boston, Massachusetts, United States of America
| |
Collapse
|
15
|
Memory instruction interacts with both visual and motoric inhibition of return. Atten Percept Psychophys 2015; 77:804-18. [PMID: 25592783 DOI: 10.3758/s13414-014-0820-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In the item-method directed forgetting paradigm, the magnitude of inhibition of return (IOR) is larger after an instruction to forget (F) than after an instruction to remember (R). In the present experiments, we further investigated this increased magnitude of IOR after F than after R memory instructions, to determine whether this F > R IOR pattern occurs only for the motoric form of IOR, as predicted, or also for the visual form. In three experiments, words were presented in one of two peripheral locations, followed by either an F or an R memory instruction. Then, a target appeared either at the same location as the previous word or at the other location. In Experiment 1, participants maintained fixation throughout the trial until the target appeared, at which point they made a saccade to the target. In Experiment 2, they maintained fixation throughout the entire trial and made a manual localization response to the target. The F > R IOR difference in reaction times occurred for both the saccadic and manual responses, suggesting that memory instructions modify both motoric and visual forms of IOR. In Experiment 3, participants made a perceptual discrimination response to report the identity of a target while the eyes remained fixed. The F > R IOR difference also occurred for these manual discrimination responses, increasing our confidence that memory instructions modify the visual form of IOR. We relate our findings to postulated differences in attentional withdrawal following F and R instructions and consider the implications of the findings for successful forgetting.
Collapse
|
16
|
Kulesz PA, Tian S, Juranek J, Fletcher JM, Francis DJ. Relations between volumetric measures of brain structure and attentional function in spina bifida: utilization of robust statistical approaches. Neuropsychology 2014; 29:212-25. [PMID: 25495830 DOI: 10.1037/neu0000166] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVE Weak structure-function relations for brain and behavior may stem from problems in estimating these relations in small clinical samples with frequently occurring outliers. In the current project, we focused on the utility of using alternative statistics to estimate these relations. METHOD Fifty-four children with spina bifida meningomyelocele performed attention tasks and received MRI of the brain. Using a bootstrap sampling process, the Pearson product-moment correlation was compared with 4 robust correlations: the percentage bend correlation, the Winsorized correlation, the skipped correlation using the Donoho-Gasko median, and the skipped correlation using the minimum volume ellipsoid estimator. RESULTS All methods yielded similar estimates of the relations between measures of brain volume and attention performance. The similarity of estimates across correlation methods suggested that the weak structure-function relations previously found in many studies are not readily attributable to the presence of outlying observations and other factors that violate the assumptions behind the Pearson correlation. CONCLUSIONS Given the difficulty of assembling large samples for brain-behavior studies, estimating correlations using multiple, robust methods may enhance the statistical conclusion validity of studies yielding small, but often clinically significant, correlations.
Collapse
Affiliation(s)
| | - Siva Tian
- Department of Psychology, University of Houston
| | - Jenifer Juranek
- Children's Learning Institute, University of Texas-Houston Health Science
| | | | | |
Collapse
|
17
|
McKenna BS, Young JW, Dawes SE, Asgaard GL, Eyler LT. Bridging the bench to bedside gap: validation of a reverse-translated rodent continuous performance test using functional magnetic resonance imaging. Psychiatry Res 2013; 212:183-91. [PMID: 23570915 DOI: 10.1016/j.pscychresns.2013.01.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 01/05/2013] [Accepted: 01/21/2013] [Indexed: 01/14/2023]
Abstract
Vigilance, which requires attending to relevant while ignoring irrelevant stimuli, is a cognitive domain impacted by schizophrenia and bipolar disorder. Various continuous performance tests (CPT) have been used to examine neural correlates of vigilance within people with and without severe mental illness, though there are limited cross-species paradigms available. The 5-choice CPT (5C-CPT) was designed for use in rodents as a cross-species translational paradigm. Here, we evaluate construct validity of a reverse-translated human analog of the 5C-CPT in assessing the neural correlates of vigilance. Functional magnetic resonance imaging during the 5C-CPT was used to examine activation of healthy individuals during target and non-target trials separately. We found activation in brain regions implicated in sustained attention processes including premotor cortex, inferior parietal lobe, basal ganglia, and thalamus during target trials. For non-target trials, we found expected activation in inferior frontal cortex, premotor cortex, presupplementary motor area, and inferior parietal lobe. Results support the construct validity of the 5C-CPT in measuring attentional and inhibitory systems within a single task paradigm enabling the assessment of vigilance across species. This task can be used for powerful parallel human and animal investigations of the biological basis of vigilance deficits in populations with severe mental illness.
Collapse
Affiliation(s)
- Benjamin S McKenna
- Mental Illness Research, Education, and Clinical Center, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA.
| | | | | | | | | |
Collapse
|
18
|
Chafee MV, Crowe DA. Thinking in spatial terms: decoupling spatial representation from sensorimotor control in monkey posterior parietal areas 7a and LIP. Front Integr Neurosci 2013; 6:112. [PMID: 23355813 PMCID: PMC3555036 DOI: 10.3389/fnint.2012.00112] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 11/05/2012] [Indexed: 11/24/2022] Open
Abstract
Perhaps the simplest and most complete description of the cerebral cortex is that it is a sensorimotor controller whose primary purpose is to represent stimuli and movements, and adaptively control the mapping between them. However, in order to think, the cerebral cortex has to generate patterns of neuronal activity that encode abstract, generalized information independently of ongoing sensorimotor events. A critical question confronting cognitive systems neuroscience at present therefore is how neural signals encoding abstract information emerge within the sensorimotor control networks of the brain. In this review, we approach that question in the context of the neural representation of space in posterior parietal cortex of non-human primates. We describe evidence indicating that parietal cortex generates a hierarchy of spatial representations with three basic levels: including (1) sensorimotor signals that are tightly coupled to stimuli or movements, (2) sensorimotor signals modified in strength or timing to mediate cognition (examples include attention, working memory, and decision-processing), as well as (3) signals that encode frankly abstract spatial information (such as spatial relationships or categories) generalizing across a wide diversity of specific stimulus conditions. Here we summarize the evidence for this hierarchy, and consider data showing that signals at higher levels derive from signals at lower levels. That in turn could help characterize neural mechanisms that derive a capacity for abstraction from sensorimotor experience.
Collapse
Affiliation(s)
- Matthew V Chafee
- Department of Neuroscience, University of Minnesota Medical School Minneapolis, MN, USA ; Brain Sciences Center, VA Medical Center Minneapolis, MN, USA ; Center for Cognitive Sciences, University of Minnesota Minneapolis, MN, USA
| | | |
Collapse
|
19
|
Schneider BA, Ghose GM. Temporal production signals in parietal cortex. PLoS Biol 2012; 10:e1001413. [PMID: 23118614 PMCID: PMC3484129 DOI: 10.1371/journal.pbio.1001413] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Accepted: 09/17/2012] [Indexed: 11/18/2022] Open
Abstract
We often perform movements and actions on the basis of internal motivations and without any explicit instructions or cues. One common example of such behaviors is our ability to initiate movements solely on the basis of an internally generated sense of the passage of time. In order to isolate the neuronal signals responsible for such timed behaviors, we devised a task that requires nonhuman primates to move their eyes consistently at regular time intervals in the absence of any external stimulus events and without an immediate expectation of reward. Despite the lack of sensory information, we found that animals were remarkably precise and consistent in timed behaviors, with standard deviations on the order of 100 ms. To examine the potential neural basis of this precision, we recorded from single neurons in the lateral intraparietal area (LIP), which has been implicated in the planning and execution of eye movements. In contrast to previous studies that observed a build-up of activity associated with the passage of time, we found that LIP activity decreased at a constant rate between timed movements. Moreover, the magnitude of activity was predictive of the timing of the impending movement. Interestingly, this relationship depended on eye movement direction: activity was negatively correlated with timing when the upcoming saccade was toward the neuron's response field and positively correlated when the upcoming saccade was directed away from the response field. This suggests that LIP activity encodes timed movements in a push-pull manner by signaling for both saccade initiation towards one target and prolonged fixation for the other target. Thus timed movements in this task appear to reflect the competition between local populations of task relevant neurons rather than a global timing signal.
Collapse
Affiliation(s)
| | - Geoffrey M. Ghose
- Department of Neuroscience, Center for Magnetic Resonance Research, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail:
| |
Collapse
|
20
|
Abstract
Lesion and functional brain imaging studies have suggested that there are two anatomically nonoverlapping attention networks. The dorsal frontoparietal network controls goal-oriented top-down deployment of attention; the ventral frontoparietal network mediates stimulus-driven bottom-up attentional reorienting. The interaction between the two networks and its functional significance has been considered in the past but no direct test has been carried out. We addressed this problem by recording fMRI data from human subjects performing a trial-by-trial cued visual spatial attention task in which the subject had to respond to target stimuli in the attended hemifield and ignore all stimuli in the unattended hemifield. Correlating Granger causal influences between regions of interest with behavioral performance, we report two main results. First, stronger Granger causal influences from the dorsal attention network (DAN) to the ventral attention network (VAN), i.e., DAN→VAN, are generally associated with enhanced performance, with right intraparietal sulcus (IPS), left IPS, and right frontal eye field being the main sources of behavior-enhancing influences. Second, stronger Granger causal influences from VAN to DAN, i.e., VAN→DAN, are generally associated with degraded performance, with right temporal-parietal junction being the main sources of behavior-degrading influences. These results support the hypothesis that signals from DAN to VAN suppress and filter out unimportant distracter information, whereas signals from VAN to DAN break the attentional set maintained by the dorsal attention network to enable attentional reorienting.
Collapse
|
21
|
Abstract
The macaque lateral intraparietal area (LIP) has been implicated in many cognitive processes, ranging from saccade planning and spatial attention to timing and categorization. Importantly, different research groups have used different criteria for including LIP neurons in their studies. While some research groups have selected LIP neurons based on the presence of memory-delay activity, other research groups have used other criteria such as visual, presaccadic, and/or memory activity. We recorded from LIP neurons that were selected based on spatially selective saccadic activity but regardless of memory-delay activity in macaque monkeys. To test anticipatory climbing activity, we used a delayed visually guided saccade task with a unimodal schedule of go-times, for which the conditional probability that the go-signal will occur rises monotonically as a function of time. A subpopulation of LIP neurons showed anticipatory activity that mimicked the subjective hazard rate of the go-signal when the animal was planning a saccade toward the receptive field. A large subgroup of LIP neurons, however, did not modulate their firing rates according to the subjective hazard function. These non-anticipatory neurons were strongly influenced by salient visual stimuli appearing in their receptive field, but less so by the direction of the impending saccade. Thus, LIP contains a heterogeneous population of neurons related to saccade planning or visual salience, and these neurons are spatially intermixed. Our results suggest that between-study differences in neuronal selection may have contributed significantly to the findings of different research groups with respect to the functional role of area LIP.
Collapse
|
22
|
Abstract
The set size effect in visual search refers to the linear increase in response time (RT) or decrease in accuracy as the number of distractors increases. Previous human and monkey studies have reported a correlation between set size and neural activity in the frontal eye field (FEF) and intraparietal sulcus (IPS). In a recent functional magnetic resonance imaging study, we did not observe a set size effect in the superior precentral sulcus (sPCS, thought to be the human homolog of the FEF) and IPS in an oculomotor visual search task (Ikkai et al., 2011). Our task used placeholders in the search array, along with the target and distractors, in order to equate the amount of retinal stimulation for each set size. We here attempted to reconcile these differences with the results from a follow-up experiment in which the same oculomotor visual search task was used, but without placeholders. A strong behavioral set size effect was observed in both studies, with very similar saccadic RTs and slopes between RT and set size. However, a set size effect was now observed in the sPCS and IPS. We comment on this finding and discuss the role of these neural areas in visual search.
Collapse
Affiliation(s)
- Trenton A Jerde
- Department of Psychology, New York University, New York, NY, USA
| | | | | |
Collapse
|
23
|
Boehnke SE, Berg DJ, Marino RA, Baldi PF, Itti L, Munoz DP. Visual adaptation and novelty responses in the superior colliculus. Eur J Neurosci 2011; 34:766-79. [PMID: 21864319 DOI: 10.1111/j.1460-9568.2011.07805.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The brain's ability to ignore repeating, often redundant, information while enhancing novel information processing is paramount to survival. When stimuli are repeatedly presented, the response of visually sensitive neurons decreases in magnitude, that is, neurons adapt or habituate, although the mechanism is not yet known. We monitored the activity of visual neurons in the superior colliculus (SC) of rhesus monkeys who actively fixated while repeated visual events were presented. We dissociated adaptation from habituation as mechanisms of the response decrement by using a Bayesian model of adaptation, and by employing a paradigm including rare trials that included an oddball stimulus that was either brighter or dimmer. If the mechanism is adaptation, response recovery should be seen only for the brighter stimulus; if the mechanism is habituation, response recovery ('dishabituation') should be seen for both the brighter and dimmer stimuli. We observed a reduction in the magnitude of the initial transient response and an increase in response onset latency with stimulus repetition for all visually responsive neurons in the SC. Response decrement was successfully captured by the adaptation model, which also predicted the effects of presentation rate and rare luminance changes. However, in a subset of neurons with sustained activity in response to visual stimuli, a novelty signal akin to dishabituation was observed late in the visual response profile for both brighter and dimmer stimuli, and was not captured by the model. This suggests that SC neurons integrate both rapidly discounted information about repeating stimuli and novelty information about oddball events, to support efficient selection in a cluttered dynamic world.
Collapse
Affiliation(s)
- Susan E Boehnke
- Centre for Neuroscience Studies, Queen's University, Kingston, Ontario, Canada.
| | | | | | | | | | | |
Collapse
|
24
|
Vasquez BP, Buck BH, Black SE, Leibovitch FS, Lobaugh NJ, Caldwell CB, Behrmann M. Visual attention deficits in Alzheimer's disease: relationship to HMPAO SPECT cortical hypoperfusion. Neuropsychologia 2011; 49:1741-50. [PMID: 21377483 DOI: 10.1016/j.neuropsychologia.2011.02.052] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 02/04/2011] [Accepted: 02/26/2011] [Indexed: 10/18/2022]
Abstract
Patients with Alzheimer's disease (AD) display a multiplicity of cognitive deficits in domains such as memory, language, and attention, all of which can be clearly linked to the underlying neuropathological alterations. The typical degenerative changes occur early on in the disease in the temporal-parietal lobes, with other brain regions, such as the frontal cortex, becoming more affected as the disease progresses. In light of the importance of the parietal cortex in mediating visuospatial attentional processing, in the present study, we investigated a deficit in covert orienting of visual attention and its relationship to cortical hypoperfusion in AD. We characterized the visual attentional profile of 21 AD patients, relative to that of 26 matched normal individuals, and then assessed the correspondence between behavior and hypoperfusion, as measured by regional cerebral blood flow using SPECT. Relative to controls, the AD group demonstrated a unilateral attentional deficit, with disproportionate slowing in reorienting attention to targets in the left compared to the right hemispace, especially following an invalid peripheral cue. Furthermore, even in the presence of bilateral pathology typical of AD, there was a positive correlation between this unilateral attentional disorder and the magnitude of the right superior parietal lobe hypoperfusion. The association of the altered attentional processing profile (i.e., greater difficulty disengaging attention from right-sided stimuli) with right-hemisphere-predominant hypoperfusion not only confirms the critical role of the right parietal lobe in covert attentional orienting but, more importantly, identifies a potential locus of the behavioral alterations in visuospatial processing in AD.
Collapse
Affiliation(s)
- Brandon P Vasquez
- Brain Sciences Research Program and Division of Neurology, Department of Medicine, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | | | | | | | | | | | | |
Collapse
|
25
|
Populin LC, Rajala AZ. Time course of allocation of spatial attention by acoustic cues in non-human primates. Eur J Neurosci 2010; 32:1040-8. [PMID: 20722717 DOI: 10.1111/j.1460-9568.2010.07366.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Spatial attention mediates the selection of information from different parts of space. When a brief cue is presented shortly before a target [cue to target onset asynchrony (CTOA)] in the same location, behavioral responses are facilitated, a process called attention capture. At longer CTOAs, responses to targets presented in the same location are inhibited; this is called inhibition of return (IOR). In the visual modality, these processes have been demonstrated in both humans and non-human primates, the latter allowing for the study of the underlying neural mechanisms. In audition, the effects of attention have only been shown in humans when the experimental task requires sound localization. Studies in monkeys with the use of similar cues but without a sound localization requirement have produced negative results. We have studied the effects of predictive acoustic cues on the latency of gaze shifts to visual and auditory targets in monkeys experienced in localizing sound sources in the laboratory with the head unrestrained. Both attention capture and IOR were demonstrated with acoustic cues, although with a faster time course than with visual cues. Additionally, the effect was observed across sensory modalities (acoustic cue to visual target), suggesting that the underlying neural mechanisms of these effects may be mediated within the superior colliculus, a center where inputs from both vision and audition converge.
Collapse
Affiliation(s)
- Luis C Populin
- Departments of Anatomy and Psychology, Neuroscience Training Program, and Eye Research Institute, University of Wisconsin-Madison, Madison, WI 53706, USA.
| | | |
Collapse
|
26
|
Caminiti R, Chafee MV, Battaglia-Mayer A, Averbeck BB, Crowe DA, Georgopoulos AP. Understanding the parietal lobe syndrome from a neurophysiological and evolutionary perspective. Eur J Neurosci 2010; 31:2320-40. [PMID: 20550568 PMCID: PMC2900452 DOI: 10.1111/j.1460-9568.2010.07291.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In human and nonhuman primates parietal cortex is formed by a multiplicity of areas. For those of the superior parietal lobule (SPL) there exists a certain homology between man and macaques. As a consequence, optic ataxia, a disturbed visual control of hand reaching, has similar features in man and monkeys. Establishing such correspondence has proven difficult for the areas of the inferior parietal lobule (IPL). This difficulty depends on many factors. First, no physiological information is available in man on the dynamic properties of cells in the IPL. Second, the number of IPL areas identified in the monkey is paradoxically higher than that so far described in man, although this issue will probably be reconsidered in future years, thanks to comparative imaging studies. Third, the consequences of parietal lesions in monkeys do not always match those observed in humans. This is another paradox if one considers that, in certain cases, the functional properties of neurons in the monkey's IPL would predict the presence of behavioral skills, such as construction capacity, that however do not seem to emerge in the wild. Therefore, constructional apraxia, which is well characterized in man, has never been described in monkeys and apes. Finally, only certain aspects, i.e. hand directional hypokinesia and gaze apraxia (Balint's psychic paralysis of gaze), of the multifaceted syndrome hemispatial neglect have been described in monkeys. These similarities, differences and paradoxes, among many others, make the study of the evolution and function of parietal cortex a challenging case.
Collapse
Affiliation(s)
- Roberto Caminiti
- Department of Physiology and Pharmacology, SAPIENZA University of Rome, 00185 Rome, Italy.
| | | | | | | | | | | |
Collapse
|
27
|
Gherri E, Eimer M. Manual response preparation disrupts spatial attention: an electrophysiological investigation of links between action and attention. Neuropsychologia 2010; 48:961-9. [PMID: 19944707 PMCID: PMC2854796 DOI: 10.1016/j.neuropsychologia.2009.11.017] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Revised: 10/05/2009] [Accepted: 11/20/2009] [Indexed: 11/16/2022]
Abstract
Previous behavioural and neuroscience studies have shown that the systems involved in the control of attention and action are functionally and anatomically linked. We used behavioural and event-related brain potential measures to investigate whether such links are mandatory or merely optional. Cues presented at the start of each trial instructed participants to shift attention to the left or right side and to simultaneously prepare to a finger movement with their left or right hand. In different trials, cues were followed by a central Go signal, requiring execution of the prepared manual response (motor task), or by a peripheral visual stimulus, which required a target-non-target discrimination only when presented on the cued side (attention task). Lateralised ERP components indicative of covert attention shifts were found when attention and action were directed to the same side (same side condition), but not when attention and action were directed to opposite sides (opposite sides condition). Likewise, effects of spatial attention on the processing of peripheral visual stimuli were present only when attention and action were directed to the same side, but not in the opposite sides condition. These results demonstrate that preparing a manual response on one side severely disrupts the attentional selection of visual stimuli on the other side, and suggest that it is not possible to simultaneously direct attention and action to different locations in space. They support the hypothesis that the control of spatial attention and action are implemented by shared brain circuits, and are therefore linked in a mandatory fashion.
Collapse
Affiliation(s)
- Elena Gherri
- School of Psychology, Birkbeck College, University of London, Malet Street, London, WC1E 7HX, United Kingdom.
| | | |
Collapse
|
28
|
Rawley JB, Constantinidis C. Effects of task and coordinate frame of attention in area 7a of the primate posterior parietal cortex. J Vis 2010; 10:12.1-16. [PMID: 20143905 DOI: 10.1167/10.1.12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 12/24/2009] [Indexed: 11/24/2022] Open
Abstract
The activity of neurons in the primate posterior parietal cortex reflects the location of visual stimuli relative to the eye, body, and world, and is modulated by selective attention and task rules. It is not known however how these effects interact with each other. To address this question, we recorded neuronal activity from area 7a of monkeys trained to perform two variants of a delayed match-to-sample task. The monkeys attended a spatial location defined in either spatiotopic (world-centered) or retinotopic (eye-centered) coordinates. We found neuronal responses to be remarkably plastic depending on the task. In contrast to previous studies using the simple version of the delayed match-to-sample task, we discovered that after training in a task where the locus of attention shifted during the trial, neural responses were typically enhanced for a match stimulus. Our results further revealed that responses were mostly enhanced for stimuli matching in spatiotopic coordinates, although the proportion of neurons modulated by either coordinate frame was influenced by the behavioral task executed.
Collapse
Affiliation(s)
- Justin B Rawley
- Department of Neurobiology and Anatomy, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1010, USA
| | | |
Collapse
|
29
|
Wardak C, Vanduffel W, Orban GA. Searching for a Salient Target Involves Frontal Regions. Cereb Cortex 2010; 20:2464-77. [DOI: 10.1093/cercor/bhp315] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
30
|
Using the MATRICS to guide development of a preclinical cognitive test battery for research in schizophrenia. Pharmacol Ther 2009; 122:150-202. [PMID: 19269307 DOI: 10.1016/j.pharmthera.2009.02.004] [Citation(s) in RCA: 256] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 02/17/2009] [Indexed: 12/29/2022]
Abstract
Cognitive deficits in schizophrenia are among the core symptoms of the disease, correlate with functional outcome, and are not well treated with current antipsychotic therapies. In order to bring together academic, industrial, and governmental bodies to address this great 'unmet therapeutic need', the NIMH sponsored the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) initiative. Through careful factor analysis and consensus of expert opinion, MATRICS identified seven domains of cognition that are deficient in schizophrenia (attention/vigilance, working memory, reasoning and problem solving, processing speed, visual learning and memory, verbal learning and memory, and social cognition) and recommended a specific neuropsychological test battery to probe these domains. In order to move the field forward and outline an approach for translational research, there is a need for a "preclinical MATRICS" to develop a rodent test battery that is appropriate for drug development. In this review, we outline such an approach and review current rodent tasks that target these seven domains of cognition. The rodent tasks are discussed in terms of their validity for probing each cognitive domain as well as a brief overview of the pharmacology and manipulations relevant to schizophrenia for each task.
Collapse
|
31
|
Young JW, Light GA, Marston HM, Sharp R, Geyer MA. The 5-choice continuous performance test: evidence for a translational test of vigilance for mice. PLoS One 2009; 4:e4227. [PMID: 19156216 PMCID: PMC2626630 DOI: 10.1371/journal.pone.0004227] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 12/09/2008] [Indexed: 11/23/2022] Open
Abstract
Background Attentional dysfunction is related to functional disability in patients with neuropsychiatric disorders such as schizophrenia, bipolar disorder, and Alzheimer's disease. Indeed, sustained attention/vigilance is among the leading targets for new medications designed to improve cognition in schizophrenia. Although vigilance is assessed frequently using the continuous performance test (CPT) in humans, few tests specifically assess vigilance in rodents. Methods We describe the 5-choice CPT (5C-CPT), an elaboration of the 5-choice serial reaction (5CSR) task that includes non-signal trials, thus mimicking task parameters of human CPTs that use signal and non-signal events to assess vigilance. The performances of C57BL/6J and DBA/2J mice were assessed in the 5C-CPT to determine whether this task could differentiate between strains. C57BL/6J mice were also trained in the 5CSR task and a simple reaction-time (RT) task involving only one choice (1CRT task). We hypothesized that: 1) C57BL/6J performance would be superior to DBA/2J mice in the 5C-CPT as measured by the sensitivity index measure from signal detection theory; 2) a vigilance decrement would be observed in both strains; and 3) RTs would increase across tasks with increased attentional load (1CRT task<5CSR task<5C-CPT). Conclusions C57BL/6J mice exhibited superior SI levels compared to DBA/2J mice, but with no difference in accuracy. A vigilance decrement was observed in both strains, which was more pronounced in DBA/2J mice and unaffected by response bias. Finally, we observed increased RTs with increased attentional load, such that 1CRT task<5CSR task<5C-CPT, consistent with human performance in simple RT, choice RT, and CPT tasks. Thus we have demonstrated construct validity for the 5C-CPT as a measure of vigilance that is analogous to human CPT studies.
Collapse
Affiliation(s)
- Jared W Young
- Department of Psychiatry, University of California San Diego, La Jolla, California, United States of America.
| | | | | | | | | |
Collapse
|
32
|
Lanyon LJ, Denham SL. Modelling attention in individual cells leads to a system with realistic saccade behaviours. Cogn Neurodyn 2009; 3:223-42. [PMID: 19125356 DOI: 10.1007/s11571-008-9073-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 12/05/2008] [Accepted: 12/05/2008] [Indexed: 12/01/2022] Open
Abstract
Single cell recordings in monkey inferior temporal cortex (IT) and area V4 during visual search tasks indicate that modulation of responses by the search target object occurs in the late portion of the cell's sensory response (Chelazzi et al. in J Neurophysiol 80:2918-2940, 1998; Cereb Cortex 11:761-772, 2001) whereas attention to a spatial location influences earlier responses (Luck et al. in J Neurophysiol 77:24-42, 1997). Previous computational models have not captured differences in the latency of these attentional effects and yet the more protracted development of the object-based effect could have implications for behaviour. We present a neurodynamic biased competition model of visual attention in which we aimed to model the timecourse of spatial and object-based attention in order to simulate cellular responses and saccade onset times observed in monkey recordings. In common with other models, a top-down prefrontal signal, related to the search target, biases activity in the ventral visual stream. However, we conclude that this bias signal is more complex than modelled elsewhere: the latency of object-based effects in V4 and IT, and saccade onset, can be accurately simulated when the target object feedback bias consists of a sensory response component in addition to a mnemonic response. These attentional effects in V4 and IT cellular responses lead to a system that is able to produce search scan paths similar to those observed in monkeys and humans, with attention being guided to locations containing behaviourally relevant stimuli. This work demonstrates that accurate modelling of the timecourse of single cell responses can lead to biologically realistic behaviours being demonstrated by the system as a whole.
Collapse
Affiliation(s)
- Linda J Lanyon
- Human Vision & Eye Movement Laboratory, Department of Ophthalmology & Visual Sciences, Medicine (Neurology), Psychology, University of British Columbia, Room 365, 3rd Floor Research Labs, VGH Eye Care Centre, 2550 Willow Street, Vancouver, BC, V5Z 3N9, Canada,
| | | |
Collapse
|
33
|
Gee AL, Ipata AE, Gottlieb J, Bisley JW, Goldberg ME. Neural enhancement and pre-emptive perception: the genesis of attention and the attentional maintenance of the cortical salience map. Perception 2008; 37:389-400. [PMID: 18491716 DOI: 10.1068/p5874] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
One of the stable hypotheses in systems neuroscience is the relationship between attention and the enhancement of visual responses when an animal attends to the stimulus in its receptive field (Goldberg and Wurtz, 1972 Journal of Neurophysiology 35 560-574). This was first discovered in the superior colliculus of the monkey: neurons in the superficial layers of the superior colliculus responded more intensely to the onset of a stimulus during blocks of trials in which the monkey had to make a saccade to it than they did during blocks of trials in which the monkey had to continue fixating a central point and not respond to the stimulus. This enhancement has been found in many brain regions, including prefrontal cortex (Boch and Goldberg, 1987 Investigative Ophthalmology 28 Supplement, 124), V4 (Moran and Desimone, 1985 Science 229 782-784), and lateral intraparietal area (Colby et al, 1996 Journal of Neurophysiology 76 2841-2852; Colby and Goldberg, 1999 Annual Review of Neuroscience 22 319-349), and even V1 (Lamme et al, 2000 Vision Research 40 1507-1521). In these studies the assumption has been that the monkey attended to the stimulus because the stimulus evoked an enhanced response. In the experiments described here we show that for abruptly appearing stimuli, attention is not related to the initial response evoked by the stimulus, but by the activity present on the salience map in the parietal cortex when the stimulus appears. Attention to the stimulus may subsequently, by a top down signal, sustain the map, but stimuli can as easily be suppressed by top down features as they can be enhanced.
Collapse
Affiliation(s)
- Angela L Gee
- Mahoney Center for Brain and Behavior, Center for Neurobiology and Kavli Institute, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
| | | | | | | | | |
Collapse
|
34
|
Ganguli S, Bisley JW, Roitman JD, Shadlen MN, Goldberg ME, Miller KD. One-dimensional dynamics of attention and decision making in LIP. Neuron 2008; 58:15-25. [PMID: 18400159 DOI: 10.1016/j.neuron.2008.01.038] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2007] [Revised: 07/23/2007] [Accepted: 01/09/2008] [Indexed: 10/22/2022]
Abstract
Where we allocate our visual spatial attention depends upon a continual competition between internally generated goals and external distractions. Recently it was shown that single neurons in the macaque lateral intraparietal area (LIP) can predict the amount of time a distractor can shift the locus of spatial attention away from a goal. We propose that this remarkable dynamical correspondence between single neurons and attention can be explained by a network model in which generically high-dimensional firing-rate vectors rapidly decay to a single mode. We find direct experimental evidence for this model, not only in the original attentional task, but also in a very different task involving perceptual decision making. These results confirm a theoretical prediction that slowly varying activity patterns are proportional to spontaneous activity, pose constraints on models of persistent activity, and suggest a network mechanism for the emergence of robust behavioral timing from heterogeneous neuronal populations.
Collapse
Affiliation(s)
- Surya Ganguli
- Sloan-Swartz Center for Theoretical Neurobiology, University of California, San Francisco, San Francisco, CA 94143, USA.
| | | | | | | | | | | |
Collapse
|
35
|
Abstract
Survival can depend on the ability to change a current course of action to respond to potentially advantageous or threatening stimuli. This "reorienting" response involves the coordinated action of a right hemisphere dominant ventral frontoparietal network that interrupts and resets ongoing activity and a dorsal frontoparietal network specialized for selecting and linking stimuli and responses. At rest, each network is distinct and internally correlated, but when attention is focused, the ventral network is suppressed to prevent reorienting to distracting events. These different patterns of recruitment may reflect inputs to the ventral attention network from the locus coeruleus/norepinephrine system. While originally conceptualized as a system for redirecting attention from one object to another, recent evidence suggests a more general role in switching between networks, which may explain recent evidence of its involvement in functions such as social cognition.
Collapse
Affiliation(s)
- Maurizio Corbetta
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gaurav Patel
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Gordon L. Shulman
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA
| |
Collapse
|
36
|
Mander BA, Reid KJ, Davuluri VK, Small DM, Parrish TB, Mesulam MM, Zee PC, Gitelman DR. Sleep deprivation alters functioning within the neural network underlying the covert orienting of attention. Brain Res 2008; 1217:148-56. [PMID: 18511023 DOI: 10.1016/j.brainres.2008.04.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 02/22/2008] [Accepted: 04/02/2008] [Indexed: 10/22/2022]
Abstract
One function of spatial attention is to enable goal-directed interactions with the environment through the allocation of neural resources to motivationally relevant parts of space. Studies have shown that responses are enhanced when spatial attention is predictively biased towards locations where significant events are expected to occur. Previous studies suggest that the ability to bias attention predictively is related to posterior cingulate cortex (PCC) activation [Small, D.M., et al., 2003. The posterior cingulate and medial prefrontal cortex mediate the anticipatory allocation of spatial attention. Neuroimage 18, 633-41]. Sleep deprivation (SD) impairs selective attention and reduces PCC activity [Thomas, M., et al., 2000. Neural basis of alertness and cognitive performance impairments during sleepiness. I. Effects of 24 h of sleep deprivation on waking human regional brain activity. J. Sleep Res. 9, 335-352]. Based on these findings, we hypothesized that SD would affect PCC function and alter the ability to predictively allocate spatial attention. Seven healthy, young adults underwent functional magnetic resonance imaging (fMRI) following normal rest and 34-36 h of SD while performing a task in which attention was shifted in response to peripheral targets preceded by spatially informative (valid), misleading (invalid), or uninformative (neutral) cues. When rested, but not when sleep-deprived, subjects responded more quickly to targets that followed valid cues than those after neutral or invalid cues. Brain activity during validly cued trials with a reaction time benefit was compared to activity in trials with no benefit. PCC activation was greater during trials with a reaction time benefit following normal rest. In contrast, following SD, reaction time benefits were associated with activation in the left intraparietal sulcus, a region associated with receptivity to stimuli at unexpected locations. These changes may render sleep-deprived individuals less able to anticipate the locations of upcoming events, and more susceptible to distraction by stimuli at irrelevant locations.
Collapse
Affiliation(s)
- Bryce A Mander
- Department of Neurology, Northwestern University, Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | | | | | | | | | | | | |
Collapse
|
37
|
Abstract
In a standard Posner paradigm, participants were endogenously cued to attend to a peripheral location in visual space without making eye movements. They responded faster to target letters presented at cued than at uncued locations. On some trials, instead of a manual response, they had to move their eyes to a location in space. Results showed that the eyes deviated away from the validly cued location; when the cue was invalid and attention had to be allocated to the uncued location, eye movements also deviated away, but now from the uncued location. The extent to which the eyes deviated from cued and uncued locations was related to the dynamics of attention allocation. We hypothesized that this deviation was due to the successful inhibition of the attended location. The results imply that the oculomotor system is not only involved during the endogenous direction of covert attention to a cued location, but also when covert attention is directed to an uncued location. It appears that the oculomotor system is activated wherever spatial attention is allocated. The strength of saccade deviation might turn out to be an important measure for the amount of attention allocated to any particular location over time.
Collapse
|
38
|
Bucci DJ, Macleod JE. Changes in neural activity associated with a surprising change in the predictive validity of a conditioned stimulus. Eur J Neurosci 2007; 26:2669-76. [PMID: 17970737 DOI: 10.1111/j.1460-9568.2007.05902.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Changes in how well a conditioned stimulus (CS) predicts future events can alter the amount of attention paid to that cue. For example, the unexpected violation of a previously established relationship between a CS and another stimulus can increase attentional processing and subsequent conditioning to that cue [J.M. Pearce & G. Hall (1980)Psych. Rev., 106, 532-552]. Previous lesion studies have implicated the central nucleus of the amygdala (CN) and basal forebrain corticopetal cholinergic system in mediating surprise-induced changes in attention. Here, expression of the immediate-early gene c-fos was used to determine which cortical targets of the basal forebrain cholinergic system are activated during an increase in attentional processing. Consistent with previous studies, increased Fos expression was observed in the posterior parietal cortex (PPC) when a visual stimulus no longer reliably predicted occurrence of a tone. Similar results were observed in the secondary auditory cortex; however, there were no significant changes in Fos expression in other auditory or visual cortices or in other cortical association areas that have been implicated in attentional function (frontal, cingulate or retrosplenial cortex). These findings support the notion that the PPC is the primary cortical component of a neural system mediating incremental changes in attention. In addition, an increase in Fos-positive cells was detected in the substantia innominata/nucleus basalis and the CN at the time of surprise. An opposite pattern of results was observed in the basal lateral nucleus of the amygdala, providing evidence for different stimulus-processing mechanisms in regions of the amygdala.
Collapse
Affiliation(s)
- David J Bucci
- Department of Psychological and Brain Sciences, Dartmouth College, Hanover, NH 03755, USA.
| | | |
Collapse
|
39
|
Vidyasagar TR, Pigarev IN. Modulation of neuronal responses in macaque primary visual cortex in a memory task. Eur J Neurosci 2007; 25:2547-57. [PMID: 17445250 DOI: 10.1111/j.1460-9568.2007.05483.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The primary visual cortex, a relatively early station in the visual pathway, has long been considered mainly as a site of basic feature detection but evidence is emerging that is consistent with the existence of feedback influences from higher cortical areas. We show that in a delayed match-to-sample memory task, where the monkey needs to remember both the visual pattern and its location, there is significant modulation of neuronal activity in the primary visual cortex suggestive of a feedback signal. Responses to identical patterns are remarkably different depending upon their place in the memory task. These modulatory influences are significantly less when the same visual patterns are shown during a simple fixation task, where these stimuli can be ignored and not attended to. The results indicate that neural processing specific to attentional and mnemonic functions can involve even primary sensory areas.
Collapse
Affiliation(s)
- Trichur R Vidyasagar
- Department of Optometry & Vision Sciences, University of Melbourne, Cnr Keppel & Cardigan Streets, Carlton, Vic 3053, Australia.
| | | |
Collapse
|
40
|
Russ BE, Kim AM, Abrahamsen KL, Kiringoda R, Cohen YE. Responses of neurons in the lateral intraparietal area to central visual cues. Exp Brain Res 2007; 174:712-27. [PMID: 16738908 DOI: 10.1007/s00221-006-0514-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Accepted: 04/20/2006] [Indexed: 11/27/2022]
Abstract
Goal-directed behavior is characterized by flexible stimulus-action mappings. The lateral intraparietal area (area LIP) contains a representation of extra-personal space that is used to guide goal-directed behavior. To examine further how area LIP contributes to these flexible stimulus-action mappings, we recorded LIP activity while rhesus monkeys participated in two different cueing tasks. In the first task, the color of a central light indicated the location of a monkey's saccadic endpoint in the absence of any other visual stimuli. In the second task, the color of a central light indicated which of two visual targets was the saccadic goal. In both tasks, LIP activity was modulated by these non-spatial cues. These observations further suggest a role for area LIP in mediating endogenous associations that link stimuli with actions.
Collapse
Affiliation(s)
- Brian E Russ
- Department of Psychological and Brain Sciences and Center for Cognitive Neuroscience, Dartmouth College, 6207 Moore, Hanover, NH 03755, USA
| | | | | | | | | |
Collapse
|
41
|
Chafee MV, Averbeck BB, Crowe DA. Representing spatial relationships in posterior parietal cortex: single neurons code object-referenced position. Cereb Cortex 2007; 17:2914-32. [PMID: 17389630 DOI: 10.1093/cercor/bhm017] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The brain computes spatial relationships as necessary to achieve behavioral goals. Loss of this spatial cognitive ability after damage to posterior parietal cortex may contribute to constructional apraxia, a syndrome in which a patient's ability to reproduce spatial relationships between the parts of an object is disrupted. To explore neural correlates of object-relative spatial representation, we recorded neural activity in parietal area 7a of monkeys performing an object construction task. We found that neurons were activated as a function of the spatial relationship between a task-critical coordinate and a reference object. Individual neurons exhibited an object-relative spatial preference, such that different neural populations were activated when the spatial coordinate was located to the left or right of the reference object. In each case, the representation was robust to translation of the reference object, and neurons maintained their object-relative preference when the position of the object varied relative to the angle of gaze and viewer-centered frames of reference. This provides evidence that the activity of a subpopulation of parietal neurons active in the construction task represented relative position as referenced to an object and not absolute position with respect to the viewer.
Collapse
Affiliation(s)
- Matthew V Chafee
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN 55455, USA.
| | | | | |
Collapse
|
42
|
Ciçek M, Gitelman D, Hurley RSE, Nobre A, Mesulam M. Anatomical physiology of spatial extinction. Cereb Cortex 2007; 17:2892-8. [PMID: 17344206 DOI: 10.1093/cercor/bhm014] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Neurologically intact volunteers participated in a functional magnetic resonance imaging experiment that simulated the unilateral (focal) and bilateral (global) stimulations used to elicit extinction in patients with hemispatial neglect. In peristriate areas, attentional modulations were selectively sensitive to contralaterally directed attention. A higher level of mapping was observed in the intraparietal sulcus (IPS), inferior parietal lobule (IPL), and inferior frontal gyrus (IFG). In these areas, there was no distinction between contralateral and ipsilateral focal attention, and the need to distribute attention globally led to greater activity than either focal condition. These physiological characteristics were symmetrically distributed in the IPS and IFG, suggesting that the effects of unilateral lesions in these 2 areas can be compensated by the contralateral hemisphere. In the IPL, the greater activation by the bilateral attentional mode was seen only in the right hemisphere. Its contralateral counterpart displayed equivalent activations when attention was distributed to the right, to the left, or bilaterally. Within the context of this experiment, the IPL of the right hemisphere emerged as the one area where unilateral lesions can cause the most uncompensated and selective impairment of global attention (without interfering with unilateral attention to either side), giving rise to the phenomenon of extinction.
Collapse
Affiliation(s)
- Metehan Ciçek
- Cognitive Neurology and Alzheimer's Disease Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | | | | | | | | |
Collapse
|
43
|
Abstract
The lateral intraparietal area (LIP) is a subdivision of the inferior parietal lobe that has been implicated in the guidance of spatial attention. In a variety of tasks, LIP provides a "salience representation" of the external world-a topographic visual representation that encodes the locations of salient or behaviorally relevant objects. Recent neurophysiological experiments show that this salience representation incorporates information about multiple behavioral variables-such as a specific motor response, reward, or category membership-associated with the task-relevant object. This integration occurs in a wide variety of tasks, including those requiring eye or limb movements or goal-directed or nontargeting operant responses. Thus, LIP acts as a multifaceted behavioral integrator that binds visuospatial, motor, and cognitive information into a topographically organized signal of behavioral salience. By specifying attentional priority as a synthesis of multiple task demands, LIP operates at the interface of perception, action, and cognition.
Collapse
Affiliation(s)
- Jacqueline Gottlieb
- Center for Neurobiology and Behavior and Department of Psychiatry, Columbia University, New York, NY 10032, USA.
| |
Collapse
|
44
|
BROUSSARD J, SARTER M, GIVENS B. Neuronal correlates of signal detection in the posterior parietal cortex of rats performing a sustained attention task. Neuroscience 2006; 143:407-17. [PMID: 17045755 PMCID: PMC3031904 DOI: 10.1016/j.neuroscience.2006.08.030] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2006] [Revised: 06/30/2006] [Accepted: 08/01/2006] [Indexed: 10/24/2022]
Abstract
The posterior parietal cortex (PPC) plays an integral role in visuospatial attention. Evidence suggests that neuronal activity in the PPC predicts the allocation of attention to stimuli. The present experiment tested the hypothesis that in rats performing a sustained attention task, the detection of signals, as opposed to missed signals, is associated with increased PPC unit activity. Single unit activity was recorded from the PPC of rats and analyzed individually and as a population vector for each recording session. A population of single units (28/111) showed significant activation evoked by signals on trials resulting in correct performance (hits). A smaller population of neurons (three/111) was activated on trials in which signals were not detected by the animals (misses). Analysis of populations of simultaneously recorded neurons indicated increased activation predicting signal detection; no population of neurons was activated on trials in which the animal incorrectly pressed the hit lever following nonsignals. The increased, hit-predicting activity was not modulated by signal duration or the presence of a visual distractor, although the distractor reduced the number of trials in which hit-predicting activity and subsequent correct detection occurred. These findings indicate that attentional signal processing in the PPC integrates successful detection of signals.
Collapse
Affiliation(s)
- J. BROUSSARD
- Department of Psychology, The Ohio State University, 55 Psychology Building, Columbus, OH 43210, USA
| | - M. SARTER
- Department of Psychology, University of Michigan, Ann Arbor, MI 48109-1043, USA
| | - B. GIVENS
- Department of Psychology, The Ohio State University, 55 Psychology Building, Columbus, OH 43210, USA
| |
Collapse
|
45
|
Balan PF, Gottlieb J. Integration of exogenous input into a dynamic salience map revealed by perturbing attention. J Neurosci 2006; 26:9239-49. [PMID: 16957080 PMCID: PMC6674497 DOI: 10.1523/jneurosci.1898-06.2006] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Although it is widely accepted that exogenous and voluntary factors jointly determine the locus of attention, the rules governing the integration of these factors are poorly understood. We investigated neural responses in the lateral intraparietal area (LIP) to transient, distracting visual perturbations presented during task performance. Monkeys performed a covert search task in which they discriminated the orientation of a target embedded among distractors, and brief visual perturbations were presented at various moments and locations during task performance. LIP neurons responded to perturbations consisting of the appearance of new objects, as well as to abrupt changes in the color, luminance, or position of existing objects. The LIP response correlated with the bottom-up behavioral effects of different perturbation types. In addition, neurons showed two types of top-down modulations. One modulation was a context-specific multiplicative gain that affected perturbation, target, and distractor activity in a spatially nonspecific manner. Gain was higher in blocks of trials in which perturbations directly marked target location than in blocks in which they invariably appeared opposite the target, thus encoding a behavioral context defined by the statistical contingency between target and perturbation location. A second modulation reflected local competitive interactions with search-related activity, resulting in the converse effect: weaker perturbation-evoked responses if perturbations appeared at the location of the target than if they appeared opposite the target. Thus, LIP encodes an abstract dimension of salience, which is shaped by local and global top-down mechanisms. These interacting mechanisms regulate responsiveness to external input as a function of behavioral context and momentary task demands.
Collapse
Affiliation(s)
| | - Jacqueline Gottlieb
- Center for Neurobiology and Behavior and
- Department of Psychiatry, Columbia University, New York, New York 10032
| |
Collapse
|
46
|
Bakola S, Gregoriou GG, Moschovakis AK, Savaki HE. Functional imaging of the intraparietal cortex during saccades to visual and memorized targets. Neuroimage 2006; 31:1637-49. [PMID: 16624587 DOI: 10.1016/j.neuroimage.2006.02.030] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2005] [Revised: 01/30/2006] [Accepted: 02/17/2006] [Indexed: 11/29/2022] Open
Abstract
The representation of perceived space and intended actions in the primate parietal cortex has been the subject of considerable debate. To address this issue, we used the quantitative 14C-deoxyglucose method to obtain maps of the activity pattern in the intraparietal cortex of rhesus monkeys executing saccades to visual and memorized targets. The principal effect induced by memory-guided saccades was found more caudally in the deepest part of the middle third of the lateral bank (within area LIPv) whereas that induced by visually guided saccades extended more rostrally and superficially in the anterior third of the bank (within area LIPd). The memory-saccade-related and the visual-saccade-related regions of activation overlapped only within area LIPv. Besides saccade execution, maximal activity in area LIPd required a visual stimulus. The region activated by visual fixation was located at the border of LIPv and LIPd, extending mainly within area LIPd, and occupying about one third of the neural space of the region activated for visual-saccades. We suggest that the lateral intraparietal cortex represents visual and motor space in segregated, albeit partially overlapping, regions.
Collapse
Affiliation(s)
- S Bakola
- Department of Basic Sciences, Faculty of Medicine, School of Health Sciences, University of Crete, Greece
| | | | | | | |
Collapse
|
47
|
Krishna BS, Steenrod SC, Bisley JW, Sirotin YB, Goldberg ME. Reaction times of manual responses to a visual stimulus at the goal of a planned memory-guided saccade in the monkey. Exp Brain Res 2006; 173:102-14. [PMID: 16538377 DOI: 10.1007/s00221-006-0370-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2005] [Accepted: 01/14/2006] [Indexed: 12/01/2022]
Abstract
Monkeys demonstrate improved contrast sensitivity at the goal of a planned memory-guided saccade (Science 299:81-86, 2003). Such perceptual improvements have been ascribed to an endogenous attentional advantage induced by the saccade plan. Speeded reaction times have also been used as evidence for attention. We therefore asked whether the attentional advantage at the goal of a planned memory-guided saccade led to speeded manual reaction times following probes presented at the saccade goal in a simple detection task. We found that monkeys showed slower manual reaction times when the probe appeared at the memorized goal of the planned saccade when compared to manual reaction times following a probe that appeared opposite the saccade goal. Flashing a distractor at the saccade goal after target presentation appeared to slow reaction times further. Our data, combined with prior results, suggest that a spatially localized inhibition operates on the neural representation of the saccade goal. This inhibition may be closely related or identical to the processes underlying inhibition-of-return. We also found that if the same detection task was interleaved with a difficult perceptual discrimination task, manual reaction times became faster when the probe was at the saccade goal. We interpret these results as being an effect of task difficulty; the more difficult interleaved task may have engaged endogenous attentional resources more effectively, allowing it to override the inhibition at the saccade goal. We construct and discuss a simple working hypothesis for the relationship between the effects of prior attention on neural activity in salience maps and on performance in detection and discrimination tasks.
Collapse
Affiliation(s)
- B Suresh Krishna
- Mahoney Center for Brain and Behavior, Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA.
| | | | | | | | | |
Collapse
|
48
|
Shimozaki S, Kingstone A, Olk B, Stowe R, Eckstein M. Classification images of two right hemisphere patients: a window into the attentional mechanisms of spatial neglect. Brain Res 2006; 1080:26-52. [PMID: 16497281 DOI: 10.1016/j.brainres.2006.01.033] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2005] [Revised: 12/27/2005] [Accepted: 01/09/2006] [Indexed: 10/25/2022]
Abstract
While spatial neglect most commonly occurs after right hemisphere lesions, damage to diverse areas within the right hemisphere may lead to neglect, possibly through different mechanisms. To identify potentially different causes of neglect, the visual information used (the 'perceptual template') in a cueing task was estimated with a novel technique known as 'classification images' for five normal observers and two male patients with right-hemisphere lesions and previous histories of spatial neglect (CM, age 85; HL, age 69). Observers made a yes/no decision on the presence of a 'White X' checkerboard signal (1.5 degrees ) at one of two locations, with trial-to-trial stimulus noise added to the 9 checkerboard squares. Prior to the stimulus, a peripheral precue (140 ms) indicated the signal location with 80% validity. The cueing effects and estimated perceptual templates for the normal observers showed no visual field differences. Consistent with previous studies of spatial neglect, both patients had difficulty with left (contralesional) signals when preceded by a right (ipsilesional) cue. Despite similar behavioral results, the patients' estimated perceptual templates in the left field suggested two different types of attentional deficits. For CM, the left template matched the signal with left-sided cues but was opposite in sign to the signal with right-sided cues, suggesting a severely disrupted selective attentional strategy. For HL, the left templates indicated a general uncertainty in localizing the signal regardless of the cue's field. In conclusion, the classification images suggested different underlying mechanisms of neglect for these two patients with similar behavioral results and hold promise in further elucidating the underlying attentional mechanisms of spatial neglect.
Collapse
Affiliation(s)
- Steven Shimozaki
- Department of Psychology, University of California, Santa Barbara, CA 93106, USA.
| | | | | | | | | |
Collapse
|
49
|
May PJ. The mammalian superior colliculus: laminar structure and connections. PROGRESS IN BRAIN RESEARCH 2006; 151:321-78. [PMID: 16221594 DOI: 10.1016/s0079-6123(05)51011-2] [Citation(s) in RCA: 443] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The superior colliculus is a laminated midbrain structure that acts as one of the centers organizing gaze movements. This review will concentrate on sensory and motor inputs to the superior colliculus, on its internal circuitry, and on its connections with other brainstem gaze centers, as well as its extensive outputs to those structures with which it is reciprocally connected. This will be done in the context of its laminar arrangement. Specifically, the superficial layers receive direct retinal input, and are primarily visual sensory in nature. They project upon the visual thalamus and pretectum to influence visual perception. These visual layers also project upon the deeper layers, which are both multimodal, and premotor in nature. Thus, the deep layers receive input from both somatosensory and auditory sources, as well as from the basal ganglia and cerebellum. Sensory, association, and motor areas of cerebral cortex provide another major source of collicular input, particularly in more encephalized species. For example, visual sensory cortex terminates superficially, while the eye fields target the deeper layers. The deeper layers are themselves the source of a major projection by way of the predorsal bundle which contributes collicular target information to the brainstem structures containing gaze-related burst neurons, and the spinal cord and medullary reticular formation regions that produce head turning.
Collapse
Affiliation(s)
- Paul J May
- Department of Anatomy, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA.
| |
Collapse
|
50
|
Bisley JW, Goldberg ME. Neural correlates of attention and distractibility in the lateral intraparietal area. J Neurophysiol 2005; 95:1696-717. [PMID: 16339000 PMCID: PMC2365900 DOI: 10.1152/jn.00848.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We examined the activity of neurons in the lateral intraparietal area (LIP) during a task in which we measured attention in the monkey, using an advantage in contrast sensitivity as our definition of attention. The animals planned a memory-guided saccade but made or canceled it depending on the orientation of a briefly flashed probe stimulus. We measured the monkeys' contrast sensitivity by varying the contrast of the probe. Both subjects had better thresholds at the goal of the saccade than elsewhere. If a task-irrelevant distractor flashed elsewhere in the visual field, the attentional advantage transiently shifted to that site. The population response in LIP correlated with the allocation of attention; the attentional advantage lay at the location in the visual field whose representation in LIP had the greatest activity when the probe appeared. During a brief period in which there were two equally active regions in LIP, there was no attentional advantage at either location. This time, the crossing point, differed in the two animals, proving a strong correlation between the activity and behavior. The crossing point of each neuron depended on the relationship of three parameters: the visual response to the distractor, the saccade-related delay activity, and the rate of decay of the transient response to the distractor. Thus the time at which attention lingers on a distractor is set by the mechanism underlying these three biophysical properties. Finally, we showed that for a brief time LIP neurons showed a stronger response to signal canceling the planned saccade than to the confirmation signal.
Collapse
Affiliation(s)
- James W Bisley
- The Laboratory of Sensorimotor Research, National Eye Institute, Bethesda, Maryland, USA
| | | |
Collapse
|