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Hao JR, Hu QM, Yang X, Wei P, Wang HY, Sun N, Gao C. Isoflurane impairs GluN2B-containing NMDA receptors trafficking and cognition via decreasing histone acetylation and EphB2 expression in aged hippocampal neurons. Basic Clin Pharmacol Toxicol 2023; 132:180-196. [PMID: 36321664 DOI: 10.1111/bcpt.13812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 07/25/2022] [Accepted: 09/04/2022] [Indexed: 11/18/2022]
Abstract
Perioperative neurocognitive disorders (PND) is a common complication that occurs among elderly patients in the perioperative course. Current clinical evidence has shown that isoflurane exposure could cause cognitive decline, but the exact molecular mechanisms remain unclear. As both NMDARs-dependent synaptic plasticity and histone acetylation play vital roles in processing learning and memory, we postulated that these alternations might occur in the isoflurane-associated PND. Here, we found that isoflurane impaired fear memory in aged mice, decreased GluN2B-containing NMDA receptors phosphorylation and trafficking, as well as the expression of EphB2, a key regulator of synaptic localization of NMDA receptors. We also identified that isoflurane could increase the expression of HDAC2, which was significantly enriched at the ephb2 gene promoter and regulated the transcription of ephb2. Furthermore, we showed that suberoylanilide hydroxamic acid (SAHA), a nonselective HDAC inhibitor or knocking-down HDAC2 rescued the cognitive dysfunction in isoflurane-treated aged mice via increasing acetylation of H3Ac, expression of EphB2 and promoting NMDA receptor trafficking. Collectively, our study highlighted the crucial role of histone posttranslational modifications for EphB2-GluN2B signals in isoflurane-associated PND, and modulating HDAC2 might be a new therapeutic strategy for isoflurane-associated PND.
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Affiliation(s)
- Jing-Ru Hao
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Qiu-Mei Hu
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Xiu Yang
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Pan Wei
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Hu-Yi Wang
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Nan Sun
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China
| | - Can Gao
- NMPA Key Laboratory for Research and Evaluation of Narcotic and Psychotropic Drugs, Jiangsu Province Key Laboratory of Anesthesiology, Jiangsu Province Key Laboratory of Anesthesia and Analgesia Application, Xuzhou Medical University, Xuzhou, Jiangsu, China.,School of Life Sciences, Xuzhou Medical University, Xuzhou, Jiangsu, China
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Christova P, James LM, Georgopoulos AP. The dynamic shaping of local cortical circuitry by sex and age, and its relation to Pattern Comparison Processing Speed. J Neurophysiol 2022; 128:395-404. [PMID: 35792497 PMCID: PMC9359636 DOI: 10.1152/jn.00252.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Previous resting-state functional magnetic resonance imaging (fMRI) studies have shown that the strength of local neural interactions decreases with distance. Here we extend that line of research to evaluate effects of sex and age on local cortical circuitry in 6 cortical areas (superior frontal, precentral, postcentral, superior parietal, inferior parietal, lateral occipital) using data acquired from 1,054 healthy young adults who participated in the Human Connectome Project. We confirmed previous findings that the strength of zero-lag correlations between prewhitened, resting-state, blood level oxygenation-dependent (BOLD) fMRI time series decreased with distance locally, and documented that the rate of decrease with distance ("spatial steepness") (a) was progressively lower from anterior to posterior areas, (b) was greater in women, especially in anterior areas, (c) increased with age, particularly for women, (d) was significantly correlated with percent inhibition, and (e) was positively and highly significantly correlated with pattern comparison processing speed (PCPS). A hierarchical tree clustering analysis of this dependence of PCPS on spatial steepness revealed a differential organization in processing that information between the two hemispheres, namely a more independent vs. a more integrative processing in the left and right hemispheres, respectively. These findings document sex and age differences in dynamic local cortical interactions, and provide evidence that spatial sharpening of these interactions may underlie cognitive processing speed differently organized in the two hemispheres.
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Affiliation(s)
- Peka Christova
- The Neuroimaging Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, United States
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Lisa M. James
- The Neuroimaging Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, United States
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, United States
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN, United States
| | - Apostolos P. Georgopoulos
- The Neuroimaging Research Group, Brain Sciences Center, Department of Veterans Affairs Health Care System, Minneapolis, MN, United States
- Department of Neuroscience, University of Minnesota Medical School, Minneapolis, MN, United States
- Department of Psychiatry, University of Minnesota Medical School, Minneapolis, MN, United States
- Department of Neurology, University of Minnesota Medical School, Minneapolis, MN, United States
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3
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Hemispheric Asymmetry in Visual Processing: An ERP Study on Spatial Frequency Gratings. Symmetry (Basel) 2021. [DOI: 10.3390/sym13020180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
A hemispheric asymmetry for the processing of global versus local visual information is known. In this study, we investigated the existence of a hemispheric asymmetry for the visual processing of low versus high spatial frequency gratings. The event-related potentials were recorded in a group of healthy right-handed volunteers from 30 scalp sites. Six types of stimuli (1.5, 3 and 6 c/deg gratings) were randomly flashed 180 times in the left and right upper hemifields. The stimulus duration was 80 ms, and the interstimulus interval (ISI) ranged between 850 and 1000 ms. Participants paid attention and responded to targets based on their spatial frequency and location. The C1 and P1 visual responses, as well as a later selection negativity and a P300 component of event-related potentials (ERPs), were quantified and subjected to repeated-measure analyses of variance (ANOVAs). Overall, the performance was faster for the right visual field (RVF), thus suggesting a left hemispheric advantage for the attentional selection of local elements. Similarly, the analysis of the mean area amplitude of the C1 (60–110 ms) sensory response showed a stronger attentional effect (F+L+ vs. F−L+) at the left occipital areas, thus suggesting the sensory nature of this hemispheric asymmetry.
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4
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Orlandi A, Proverbio AM. ERP indices of an orientation-dependent recognition of the human body schema. Neuropsychologia 2020; 146:107535. [PMID: 32561310 DOI: 10.1016/j.neuropsychologia.2020.107535] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 06/10/2020] [Accepted: 06/11/2020] [Indexed: 01/03/2023]
Abstract
While it is well-established that the face perception is orientation-dependent, less evidence has been provided on the effects of the orientation on the body schema processing and related attentive mechanisms. Poorer performance in same/different judgment tasks and increased occipito-temporal N1 response to the inverted (vs. upright) body schema seem to hint at an orientation-dependent perceptual mechanism. The present electrophysiological study investigated the role of attentive selection processes required to recognize the inverted (vs. upright) body schema by means of the event-related potentials (ERP). 320 different images depicting body shapes (wooden dummies) as opposed to random structures of cubes were created in 3D graphics. Thirty-two right-handed participants were presented with the stimuli in an upright and inverted orientation. They were required to alternatively recognize one of the two categories of stimuli (by button press) regardless of the orientation, during EEG recording. The body inversion led to increased reaction times during body schema recognition. A slower anterior N2, larger N1, Selection Negativity (SN), and increased parietal P300 components were elicited by the perception of the inverted body schema. Slower stimulus processing and increased attention allocation were associated with the processing of the inverted body schema. The swLORETA source reconstruction (in the SN time window) showed enhanced engagement of prefrontal, limbic, and temporal regions during the perception of the inverted body schema. At the same time, the cubes' orientation did not affect ERP amplitudes. Overall, these pieces of evidence seem to suggest a crucial role of the upright orientation in the visual recognition of the human body schema.
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Affiliation(s)
- Andrea Orlandi
- Neuro-MI, Milan Center for Neuroscience, Dept. of Psychology, University of Milano - Bicocca, Piazza Dell'Ateneo Nuovo 1, 20126, Milan, Italy; Department of Psychology, "Sapienza" University of Rome, Via dei Marsi, 78, 00185, Rome, Italy.
| | - Alice Mado Proverbio
- Neuro-MI, Milan Center for Neuroscience, Dept. of Psychology, University of Milano - Bicocca, Piazza Dell'Ateneo Nuovo 1, 20126, Milan, Italy
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Orlandi A, Proverbio AM. Left-Hemispheric Asymmetry for Object-Based Attention: an ERP Study. Brain Sci 2019; 9:E315. [PMID: 31717267 PMCID: PMC6896090 DOI: 10.3390/brainsci9110315] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 10/30/2019] [Accepted: 11/06/2019] [Indexed: 01/11/2023] Open
Abstract
It has been shown that selective attention enhances the activity in visual regions associated with stimulus processing. The left hemisphere seems to have a prominent role when non-spatial attention is directed towards specific stimulus features (e.g., color, spatial frequency). The present electrophysiological study investigated the time course and neural correlates of object-based attention, under the assumption of left-hemispheric asymmetry. Twenty-nine right-handed participants were presented with 3D graphic images representing the shapes of different object categories (wooden dummies, chairs, structures of cubes) which lacked detail. They were instructed to press a button in response to a target stimulus indicated at the beginning of each run. The perception of non-target stimuli elicited a larger anterior N2 component, which was likely associated with motor inhibition. Conversely, target selection resulted in an enhanced selection negativity (SN) response lateralized over the left occipito-temporal regions, followed by a larger centro-parietal P300 response. These potentials were interpreted as indexing attentional selection and categorization processes, respectively. The standardized weighted low-resolution electromagnetic tomography (swLORETA) source reconstruction showed the engagement of a fronto-temporo-limbic network underlying object-based visual attention. Overall, the SN scalp distribution and relative neural generators hinted at a left-hemispheric advantage for non-spatial object-based visual attention.
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Affiliation(s)
- Andrea Orlandi
- Neuro-MI, Milan Center for Neuroscience, Dept. of Psychology, University of Milano - Bicocca, Milan 20126, Italy;
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Küper K, Zimmer HD. The impact of perceptual changes to studied items on ERP correlates of familiarity and recollection is subject to hemispheric asymmetries. Brain Cogn 2018; 122:17-25. [PMID: 29396208 DOI: 10.1016/j.bandc.2018.01.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 12/28/2017] [Accepted: 01/11/2018] [Indexed: 01/24/2023]
Abstract
It is still unclear which role the right hemisphere (RH) preference for perceptually specific and the left hemisphere (LH) bias towards abstract memory representations play at the level of episodic memory retrieval. When stimulus characteristics hampered the retrieval of abstract memory representations, these hemispheric asymmetries have previously only modulated event-related potential (ERP) correlates of recollection (late positive complex, LPC), but not of familiarity (FN400). In the present experiment, we used stimuli which facilitated the retrieval of abstract memory representations. With the divided visual field technique, new items, identical repetitions and color-modified versions of incidentally studied object pictures were presented in either the right (RVF) or the left visual field (LVF). Participants performed a memory inclusion task, in which they had to categorize both identically repeated and color-modified study items as 'old'. Only ERP, but not behavioral data showed hemispheric asymmetries: Compared to identical repetitions, FN400 and LPC old/new effects for color-modified items were equivalent with RVF/LH presentation, but reduced with LVF/RH presentation. By promoting the use of abstract stimulus information for memory retrieval, we were thus able to show that hemispheric asymmetries in accessing abstract or specific memory representations can modulate ERP correlates of familiarity as well as recollection processes.
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Affiliation(s)
- Kristina Küper
- Aging Group, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Brain & Cognition Group, Department of Psychology, Saarland University, Saarbrücken, Germany.
| | - Hubert D Zimmer
- Brain & Cognition Group, Department of Psychology, Saarland University, Saarbrücken, Germany
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Rubia K, Lim L, Ecker C, Halari R, Giampietro V, Simmons A, Brammer M, Smith A. Effects of age and gender on neural networks of motor response inhibition: from adolescence to mid-adulthood. Neuroimage 2013; 83:690-703. [PMID: 23845427 DOI: 10.1016/j.neuroimage.2013.06.078] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 06/19/2013] [Accepted: 06/29/2013] [Indexed: 11/28/2022] Open
Abstract
Functional inhibitory neural networks mature progressively with age. However, nothing is known about the impact of gender on their development. This study employed functional magnetic resonance imaging (fMRI) to investigate the effects of age, sex, and sex by age interactions on the brain activation of 63 healthy males and females, between 13 and 38 years, performing a Stop task. Increasing age was associated with progressively increased activation in typical response inhibition areas of right inferior and dorsolateral prefrontal and temporo-parietal regions. Females showed significantly enhanced activation in left inferior and superior frontal and striatal regions relative to males, while males showed increased activation relative to females in right inferior and superior parietal areas. Importantly, left frontal and striatal areas that showed increased activation in females, also showed significantly increased functional maturation in females relative to males, while the right inferior parietal activation that was increased in males showed significantly increased functional maturation relative to females. The findings demonstrate for the first time that sex-dimorphic activation patterns of enhanced left fronto-striatal activation in females and enhanced right parietal activation in males during motor inhibition appear to be the result of underlying gender differences in the functional maturation of these brain regions.
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Affiliation(s)
- Katya Rubia
- Department of Child and Adolescent Psychiatry, Institute of Psychiatry, King's College London, London, UK.
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8
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Mikhailova E, Slavutskaya A, Gerasimenko N. Gender differences in the recognition of spatially transformed figures: Behavioral data and event-related potentials (ERPs). Neurosci Lett 2012; 524:74-8. [DOI: 10.1016/j.neulet.2012.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2011] [Revised: 04/03/2012] [Accepted: 07/06/2012] [Indexed: 11/26/2022]
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9
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Liu B, Meng X, Wu G, Huang Y. Feature precedence in processing multifeature visual information in the human brain: an event-related potential study. Neuroscience 2012; 210:145-51. [DOI: 10.1016/j.neuroscience.2012.03.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Revised: 03/02/2012] [Accepted: 03/03/2012] [Indexed: 10/28/2022]
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Examining the sex difference in lateralisation for processing facial emotion: Does biological sex or psychological gender identity matter? Neuropsychologia 2010; 48:1289-94. [PMID: 20036677 DOI: 10.1016/j.neuropsychologia.2009.12.032] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/15/2009] [Accepted: 12/17/2009] [Indexed: 11/23/2022]
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11
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Electrophysiological evidence for effects of color knowledge in object recognition. Neurosci Lett 2009; 469:405-10. [PMID: 20026380 DOI: 10.1016/j.neulet.2009.12.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 12/12/2009] [Accepted: 12/15/2009] [Indexed: 11/22/2022]
Abstract
Knowledge about the typical colors associated with familiar everyday objects (i.e., strawberries are red) is well-known to be represented in the conceptual semantic system. Evidence that such knowledge may also play a role in early perceptual processes for object recognition is scant. In the present ERP study, participants viewed a list of object pictures and detected infrequent stimulus repetitions. Results show that shortly after stimulus onset, ERP components indexing early perceptual processes, including N1, P2, and N2, differentiated between objects in their appropriate or congruent color from these objects in an inappropriate or incongruent color. Such congruence effect also occurred in N3 associated with semantic processing of pictures but not in N4 for domain-general semantic processing. Our results demonstrate a clear effect of color knowledge in early object recognition stages and support the following proposal-color as a surface property is stored in a multiple-memory system where pre-semantic perceptual and semantic conceptual representations interact during object recognition.
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Sex-dependent age modulation of frontostriatal and temporo-parietal activation during cognitive control. Neuroimage 2009; 48:223-36. [PMID: 19580877 DOI: 10.1016/j.neuroimage.2009.06.070] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2008] [Revised: 01/14/2009] [Accepted: 06/29/2009] [Indexed: 11/21/2022] Open
Abstract
Developmental functional imaging studies of cognitive control show progressive age-related increase in task-relevant fronto-striatal activation in male development from childhood to adulthood. Little is known, however, about how gender affects this functional development. In this study, we used event related functional magnetic resonance imaging to examine effects of sex, age, and their interaction on brain activation during attentional switching and interference inhibition, in 63 male and female adolescents and adults, aged 13 to 38. Linear age correlations were observed across all subjects in task-specific frontal, striatal and temporo-parietal activation. Gender analysis revealed increased activation in females relative to males in fronto-striatal areas during the Switch task, and laterality effects in the Simon task, with females showing increased left inferior prefrontal and temporal activation, and males showing increased right inferior prefrontal and parietal activation. Increased prefrontal activation clusters in females and increased parietal activation clusters in males furthermore overlapped with clusters that were age-correlated across the whole group, potentially reflecting more mature prefrontal brain activation patterns for females, and more mature parietal activation patterns for males. Gender by age interactions further supported this dissociation, revealing exclusive female-specific age correlations in inferior and medial prefrontal brain regions during both tasks, and exclusive male-specific age correlations in superior parietal (Switch task) and temporal regions (Simon task). These findings show increased recruitment of age-correlated prefrontal activation in females, and of age-correlated parietal activation in males, during tasks of cognitive control. Gender differences in frontal and parietal recruitment may thus be related to gender differences in the neurofunctional maturation of these brain regions.
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Ratcliff JJ, Greenspan AI, Goldstein FC, Stringer AY, Bushnik T, Hammond FM, Novack TA, Whyte J, Wright DW. Gender and traumatic brain injury: Do the sexes fare differently? Brain Inj 2009; 21:1023-30. [PMID: 17891564 DOI: 10.1080/02699050701633072] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
OBJECTIVE To examine the relationship between gender and cognitive recovery 1 year following traumatic brain injury (TBI). METHODS Patients with blunt TBI were identified from the TBI Model Systems of Care National Database, multi-centre cohort study. The included patients (n = 325) were 16-45 years at injury, admitted to an acute care facility within 24 hours, received inpatient rehabilitation, had documented admission Glasgow Coma Scale (GCS) scores, completed neuropsychological follow-up 1 year post-injury and did not report pre-morbid learning problems. Multivariate analyses of variance examined the unadjusted association between gender and six cognitive domains examining attention/working memory, verbal memory, language, visual analytic skills, problem-solving and motor functioning. Analyses of covariance models were constructed to determine if confounding factors biased the observed associations. RESULTS Females performed significantly better than males on tests of attention/working memory and language. Males outperformed females in visual analytic skills. Gender remained significantly associated with performance in these areas when controlling for confounding variables. CONCLUSIONS These results suggest a better cognitive recovery of females than males following TBI. However, future studies need to include non-TBI patients to control for possible pre-injury gender-related differences, as well as to conduct extended follow-ups to determine the stability of the observed differences.
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Affiliation(s)
- Jonathan J Ratcliff
- Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, USA
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Christova PS, Lewis SM, Tagaris GA, Uğurbil K, Georgopoulos AP. A voxel-by-voxel parametric fMRI study of motor mental rotation: hemispheric specialization and gender differences in neural processing efficiency. Exp Brain Res 2008; 189:79-90. [DOI: 10.1007/s00221-008-1405-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2007] [Accepted: 04/22/2008] [Indexed: 12/01/2022]
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Kimberley TJ, Birkholz DD, Hancock RA, VonBank SM, Werth TN. Reliability of fMRI during a continuous motor task: assessment of analysis techniques. J Neuroimaging 2008; 18:18-27. [PMID: 18190491 DOI: 10.1111/j.1552-6569.2007.00163.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
The purpose of this study was to determine which method of functional magnetic resonance image analysis had the highest reliability in cortical and cerebellar areas during a continuous motor task. Fourteen subjects underwent 4 testing trials during 2 testing sessions separated by 3 weeks. Subjects performed a joystick task. Methods of analysis evaluated included: percent signal intensity change, active voxel count, and percent contribution. Two types of activation thresholds were evaluated: P< or = .05 and false discovery rate = .05. Reliability was determined with intraclass correlation coefficients and a repeated measure ANOVA was used to determine whether there was a significant difference between trials. A group analysis was assessed with coefficient of variation. Results indicate within session reliability was higher than between session and that signal intensity is more reliable than voxel count analysis. The intraclass correlation coefficients across different regions of interest varied depending on analysis technique. The data did not support a clear difference between thresholds. The group analysis also found less variability with intensity measures than voxel count. A stabilization effect was seen after the first trial of the experiment, suggesting that in pretest/posttest designs, a more stable result may be obtained by performing a test trial prior to actual data collection.
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16
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Is there continuity between categorical and coordinate spatial relations coding? Evidence from a grid/no-grid working memory paradigm. Neuropsychologia 2007; 46:576-94. [PMID: 18037455 DOI: 10.1016/j.neuropsychologia.2007.10.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Revised: 10/04/2007] [Accepted: 10/05/2007] [Indexed: 11/22/2022]
Abstract
We ask the question whether the coding of categorical versus coordinate spatial relations depends on different neural networks showing hemispheric specialization or whether there is continuity between these two coding types. The 'continuous spatial coding' hypothesis would mean that the two coding types rely essentially on the same neural network consisting of more general-purpose processes, such as visuo-spatial attention, but with a different weighting of these general processes depending on exact task requirements. With event-related fMRI, we have studied right-handed male subjects performing a grid/no-grid visuo-spatial working memory task inducing categorical and coordinate spatial relations coding. Our data support the 'continuous spatial coding' hypothesis, indicating that, while based on the same fronto-parieto-occipital neural network than categorical spatial relations coding, the coding of coordinate spatial relations relies more heavily on attentional and executive processes, which could induce hemispheric differences similar to those described in the literature. The results also show that visuo-spatial working memory consists of a short-term posterior store with a capacity of up to three elements in the parietal and extrastriate cortices. This store depends on the presence of a visible space categorization and thus can be used for the coding of categorical spatial relations. When no visible space categorization is given or when more than three elements have to be coded, additional attentional and executive processes are recruited, mainly located in the dorso-lateral prefrontal cortex.
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Abstract
Neuroimaging is an emergent method of investigation for studying the human brain in healthy and impaired populations. An increasing number of these investigations involve topics important to rehabilitation. Thus, a basic understanding of the more commonly used neuroimaging techniques is important for understanding and interpreting this growing area of research. Included in this article is a description of the signal source, the advantages and limitations of each technique, considerations for study design, and how to interpret cortical imaging data. Particular emphasis is placed on functional magnetic resonance imaging because of its ubiquitous presence in rehabilitation research.
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Bell EC, Willson MC, Wilman AH, Dave S, Silverstone PH. Males and females differ in brain activation during cognitive tasks. Neuroimage 2006; 30:529-38. [PMID: 16260156 DOI: 10.1016/j.neuroimage.2005.09.049] [Citation(s) in RCA: 182] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 05/16/2005] [Accepted: 09/28/2005] [Indexed: 10/25/2022] Open
Abstract
To examine the effect of gender on regional brain activity, we utilized functional magnetic resonance imaging (fMRI) during a motor task and three cognitive tasks; a word generation task, a spatial attention task, and a working memory task in healthy male (n = 23) and female (n = 10) volunteers. Functional data were examined for group differences both in the number of pixels activated, and the blood-oxygen-level-dependent (BOLD) magnitude during each task. Males had a significantly greater mean activation than females in the working memory task with a greater number of pixels being activated in the right superior parietal gyrus and right inferior occipital gyrus, and a greater BOLD magnitude occurring in the left inferior parietal lobe. However, despite these fMRI changes, there were no significant differences between males and females on cognitive performance of the task. In contrast, in the spatial attention task, men performed better at this task than women, but there were no significant functional differences between the two groups. In the word generation task, there were no external measures of performance, but in the functional measurements, males had a significantly greater mean activation than females, where males had a significantly greater BOLD signal magnitude in the left and right dorsolateral prefrontal cortex, the right inferior parietal lobe, and the cingulate. In neither of the motor tasks (right or left hand) did males and females perform differently. Our fMRI findings during the motor tasks were a greater mean BOLD signal magnitude in males in the right hand motor task, compared to females where males had an increased BOLD signal magnitude in the right inferior parietal gyrus and in the left inferior frontal gyrus. In conclusion, these results demonstrate differential patterns of activation in males and females during a variety of cognitive tasks, even though performance in these tasks may not vary, and also that variability in performance may not be reflected in differences in brain activation. These results suggest that in functional imaging studies in clinical populations it may be sensible to examine each sex independently until this effect is more fully understood.
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Affiliation(s)
- Emily C Bell
- Departments of Psychiatry and Neuroscience, University of Alberta 1E1.07 Mackenzie Center Edmonton, Alberta, Canada T6G 2B7
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Pedersen M, Barrios FA. Comparison of different statistical analyses in visual stimulus FMRI. J Neuroradiol 2006; 33:81-6. [PMID: 16733420 DOI: 10.1016/s0150-9861(06)77235-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The present study evaluated four different clinically relevant statistical approaches with respect to a response to a visual stimulus paradigm. Healthy volunteers were subjected to a visual stimulus consisting of a checkerboard black-and-white box car pattern with on-off blocks of 10s. Simultaneously, sensitivity encoding (SENSE) dynamic MR imaging was acquired using a 1.5 T MR system. Statistical analyses were conducted with z-cluster analysis, Student's t-test, Spearman's correlation, and time-series normalized cross-correlation. A figure-of-merit for neural activity was measured from calculated maps using pixel counting. The results demonstrated that the index of activity estimated from the number of "activated" pixels did not differ markedly among the four different statistical methods, except when comparing the cross-correlation statistics with z-clustering in the whole brain, implying that all methods lead to similar statistical information when using fMRI to map the activity of the visual cortex in response to a visual stimulus.
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Affiliation(s)
- M Pedersen
- Imagerie Moléculaire et Fonctionnelle: de la Physiologie à la Thérapie, Université Victor Segalen Bordeaux 2, Bordeaux, France.
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20
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Abstract
The present study re-assesses the question whether deficits, after brain damage, in constructional tasks can be partitioned in different types of disorders of spatial cognition. Based on a current cognitive neuroscience account, originally proposed by Kosslyn [Kosslyn, S. M. (1987). Seeing and imagining in the cerebral hemispheres: A computational approach. Psychological Review, 94, 148-175], that posits two complementary lateralized systems for the encoding of (categorical and coordinate) spatial relations, it is here proposed that two qualitatively different types of "constructional apraxia" can occur and that the nature of the constructional impairment after unilateral lesions closely reflects the loss of lateralized components for the perceptual processing of differing types of spatial relations. New evidence is presented, based on the study of two groups of patients with unilateral posterior brain lesions, which supports such a bipartition of constructional apraxia. In addition, past evidence is reviewed in the light of this new cognitive neuroscience account.
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Affiliation(s)
- Bruno Laeng
- Department of Psychology, University of Tromsø, Norway.
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21
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Gizewski ER, Krause E, Wanke I, Forsting M, Senf W. Gender-specific cerebral activation during cognitive tasks using functional MRI: comparison of women in mid-luteal phase and men. Neuroradiology 2005; 48:14-20. [PMID: 16328492 DOI: 10.1007/s00234-005-0004-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2005] [Accepted: 06/15/2005] [Indexed: 02/06/2023]
Abstract
Previous studies of gender-specific differences in functional imaging during spatial and language tasks have been inconclusive. Furthermore, among women, such differences may occur during mid-luteal phase compared to the rest of the menstrual cycle. In order to examine further gender differences, functional MRI was performed in 12 male volunteers and 12 female volunteers (in the mid-luteal phase) during mental rotation and verb-generation tests. Two-sample t-tests with uncorrected P values of <0.001 for the specific regions of interest (ROIs) revealed cerebral activation differences in both stimuli. During mental rotation tests, higher levels of activation were noted in the right medial frontal, precentral, and bilateral inferior parietal cortex, while in women this occurred in the right inferior and medial temporal, right superior frontal cortex, and left fusiform gyrus. During verb-generation tests, higher levels of activation in men was found in the left medial temporal and precentral cortex. Our results indicate that differences in cerebral activity during cognitive tasks can be shown between men and women in the mid-luteal phase. Gender differences while performing a mental rotation task were more prominent than during a verb-generation task.
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Affiliation(s)
- Elke R Gizewski
- Department of Diagnostic, University Hospital Essen, Essen, Germany.
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22
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Van Boven RW, Ingeholm JE, Beauchamp MS, Bikle PC, Ungerleider LG. Tactile form and location processing in the human brain. Proc Natl Acad Sci U S A 2005; 102:12601-5. [PMID: 16116098 PMCID: PMC1188260 DOI: 10.1073/pnas.0505907102] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To elucidate the neural basis of the recognition of tactile form and location, we used functional MRI while subjects discriminated gratings delivered to the fingertip of either the right or left hand. Subjects were required to selectively attend to either grating orientation or grating location under identical stimulus conditions. Independent of the hand that was stimulated, grating orientation discrimination selectively activated the left intraparietal sulcus, whereas grating location discrimination selectively activated the right temporoparietal junction. Hence, hemispheric dominance appears to be an organizing principle for cortical processing of tactile form and location.
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Affiliation(s)
- Robert W Van Boven
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Department of Health and Human Services, Bethesda, MD 20892, USA
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23
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Bell EC, Willson MC, Wilman AH, Dave S, Silverstone PH. Differential effects of chronic lithium and valproate on brain activation in healthy volunteers. Hum Psychopharmacol 2005; 20:415-24. [PMID: 16106488 DOI: 10.1002/hup.710] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
RATIONALE Previous functional imaging studies have shown altered brain activity during cognitive task performance in bipolar patients. However, the fact that these patients are often on medication makes it unclear to what extent these changes reflect treatment effects. OBJECTIVES This study aims to identify regional brain activity changes occurring following lithium and valproate treatment in healthy volunteers. METHODS This was a double-blind, placebo-controlled, study in which volunteers received either 1000 mg sodium valproate (n = 12), 900 mg lithium (n = 9), or placebo (n = 12). Functional images were acquired using functional magnetic resonance imaging (fMRI) while subjects performed three cognitive tasks, a word generation paradigm, a spatial attention task and a working memory task. fMRI was carried out both before and after 14 days of treatment with valproate, lithium or placebo. The changes in the magnitude of the blood-oxygen-level-dependent (BOLD) signal after treatment were compared between the groups using a one-way ANOVA for each task followed by a post-hoc multiple comparisons correction. RESULTS A significant group effect was noted in the change in BOLD signal magnitude from baseline to post-treatment, in all three tasks (working memory p< 0.000; spatial attention task p = 0.003; word generation paradigm p = 0.030). In the working memory task, the lithium group had a significant decrease in BOLD signal change, compared with the control group (p< 0.000). A decrease in BOLD signal change was also noted in the valproate group, in the spatial attention task (p = 0.004). Both lithium and valproate groups had a decreased BOLD signal in the verbal task, following treatment, compared with the placebo group (p = 0.061 (lithium approached significance); p = 0.050 (valproate)). CONCLUSIONS These findings suggest that lithium and valproate have independent effects on brain activation that vary in a task and region-dependent manner.
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Affiliation(s)
- Emily C Bell
- Department of Psychiatry, Faculty of Medicine, University of Alberta, Edmonton, Alberta, Canada
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24
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Lewis SM, Jerde TA, Tzagarakis C, Gourtzelidis P, Georgopoulos MA, Tsekos N, Amirikian B, Kim SG, Uğurbil K, Georgopoulos AP. Logarithmic transformation for high-field BOLD fMRI data. Exp Brain Res 2005; 165:447-53. [PMID: 16021433 DOI: 10.1007/s00221-005-2336-4] [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: 08/27/2004] [Accepted: 02/22/2005] [Indexed: 11/29/2022]
Abstract
Parametric statistical analyses of BOLD fMRI data often assume that the data are normally distributed, the variance is independent of the mean, and the effects are additive. We evaluated the fulfilment of these conditions on BOLD fMRI data acquired at 4 T from the whole brain while 15 subjects fixated a spot, looked at a geometrical shape, and copied it using a joystick. We performed a detailed analysis of the data to assess (a) their frequency distribution (i.e. how close it was to a normal distribution), (b) the dependence of the standard deviation (SD) on the mean, and (c) the dependence of the response on the preceding baseline. The data showed a strong departure from normality (being skewed to the right and hyperkurtotic), a strong linear dependence of the SD on the mean, and a proportional response over the baseline. These results suggest the need for a logarithmic transformation. Indeed, the log transformation reduced the skewness and kurtosis of the distribution, stabilized the variance, and made the effect additive, i.e. independent of the baseline. We conclude that high-field BOLD fMRI data need to be log-transformed before parametric statistical analyses are applied.
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Affiliation(s)
- Scott M Lewis
- Veterans Affairs Medical Center, Brain Sciences Center, One Veterans Drive, Minneapolis, MN 55417, USA.
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25
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Bourne VJ. Lateralised processing of positive facial emotion: sex differences in strength of hemispheric dominance. Neuropsychologia 2005; 43:953-6. [PMID: 15716165 DOI: 10.1016/j.neuropsychologia.2004.08.007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2004] [Revised: 08/25/2004] [Accepted: 08/31/2004] [Indexed: 10/26/2022]
Abstract
Sex differences in lateralisation have been examined frequently, but have found varying and contradictory results. The experiment presented in this paper examines the lateralisation of processing positive facial emotion in 276 right handed undergraduates (138 males, 138 females). All participants completed two behavioural tests of lateralisation: a handedness preference questionnaire and a chimeric faces emotion judgement task, which measured strength of lateralisation for the perception of positive facial emotion. A highly significant difference was found for the chimeric faces task only: males were more strongly lateralised than females, although both males and females tended to be right hemisphere dominant. The results suggest that females are more bilaterally distributed and hence have greater access to mechanisms located in each hemisphere.
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Affiliation(s)
- Victoria J Bourne
- Department of Mental Health, Clinical Research Centre, University of Aberdeen, Scotland AB25 2ZH, UK.
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26
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Gourtzelidis P, Tzagarakis C, Lewis SM, Crowe DA, Auerbach E, Jerde TA, Uğurbil K, Georgopoulos AP. Mental maze solving: directional fMRI tuning and population coding in the superior parietal lobule. Exp Brain Res 2005; 165:273-82. [PMID: 15940493 DOI: 10.1007/s00221-005-2298-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2004] [Accepted: 02/01/2005] [Indexed: 10/25/2022]
Abstract
The superior parietal lobule (SPL) of six human subjects was imaged at 4 T during mental traversing of a directed maze path. Here we demonstrate the orderly involvement of the SPL in this function, as follows. Forty-two percent of the voxels were tuned with respect to the direction of the maze path. This suggests a coherent tuning of local neuronal populations contributing to the change of the single-voxel BOLD signal. Preferred directions ranged throughout the directional continuum of 360 degrees. Voxels with similar preferred directions tended to cluster together: on average there were seven same-direction clusters per slice, with an average cluster membership of five voxels/cluster and an average nearest-neighbor same-direction intercluster distance of 13.1 mm. On the other hand, the average nearest-neighbor intercluster distance between a given direction and all other directions was 3.1 mm. This suggests a patchy arrangement such that patches of directionally tuned voxels, containing voxels with different preferred directions, alternate with patches of non-tuned voxels. Finally, the population vector predicted accurately the direction of the maze path (with an error of 12.7 degrees), and provided good estimates (with an error of 29 degrees) when calculated within parts of the SPL. Altogether, these findings document a new, orderly functional organization of the SPL with respect to mental tracing.
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Affiliation(s)
- Pavlos Gourtzelidis
- Brain Sciences Center, Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, USA
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27
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Francis JT, Chapin JK. Force Field Apparatus for Investigating Movement Control in Small Animals. IEEE Trans Biomed Eng 2004; 51:963-5. [PMID: 15188864 DOI: 10.1109/tbme.2004.827463] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
As part of our overall effort to build a closed loop brain-machine interface (BMI), we have developed a simple, low weight, and low inertial torque manipulandum that is ideal for use in motor system investigations with small animals such as rats. It is inexpensive and small but emulates features of large and very expensive systems currently used in monkey and human research. Our device consists of a small programmable torque-motor system that is attached to a manipulandum. Rats are trained to grasp this manipulandum and move it to one or more targets against programmed force field perturbations. Here we report several paradigms that may be used with this device and results from rat's making reaching movements in a variety of force fields. These and other available experimental manipulations allow one to experimentally separate several key variables that are critical for understanding and ultimately emulating the feedforward and feedback mechanisms of motor control.
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Affiliation(s)
- Joseph T Francis
- State University of New York Downstate School of Medicine, 450 Clarkson Ave., Brooklyn, NY 11203, USA.
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28
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Proverbio AM, Burco F, del Zotto M, Zani A. Blue piglets? Electrophysiological evidence for the primacy of shape over color in object recognition. ACTA ACUST UNITED AC 2004; 18:288-300. [PMID: 14741315 DOI: 10.1016/j.cogbrainres.2003.10.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The goal of the study was to investigate how the color and shape of visual stimuli are processed when they are conjointly presented and represent real, and familiar, entities for which normal individuals presumably have a specific 'object color knowledge' (e.g., piglets are pink, artichokes are green). There is evidence, from event related potential (ERP) literature on selective attention to color in conjunction with other, arbitrarily related, stimulus dimensions (e.g., geometrical shape), that color is processed faster than shape, and that the processing of shape depends on color relevance. In this study we recorded ERPs from 28 scalp sites in right-handed volunteers performing selective attention tasks to either color or shape of pictures representing familiar objects and animals. The results revealed that the selection of color was faster, and probably less demanding, than that of shape. However, it was also evidenced that the selection of color depended on object shape, but not vice versa. Indeed, in the attend-color condition, the N2 responses were significantly greater when stimulus shape was prototypically associated, rather than unassociated, with the color perceived. Topographical mapping of difference voltages identified the posterior occipito/temporal region of the left hemisphere as the possible locus of conjoined color and shape processing. Overall, the data support object-based attention models.
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29
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Pins D, Meyer ME, Foucher J, Humphreys G, Boucart M. Neural correlates of implicit object identification. Neuropsychologia 2004; 42:1247-59. [PMID: 15178176 DOI: 10.1016/j.neuropsychologia.2004.01.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2003] [Revised: 01/29/2004] [Accepted: 01/30/2004] [Indexed: 10/26/2022]
Abstract
The present study sought to assess neural correlates of implicit identification of objects by means of fMRI, using tasks that require matching of the physical properties of objects. Behavioural data suggests that there is automatic access to object identity when observers attend to a physical property of the form of an object (e.g. the object's orientation) and no evidence for semantic processing when subjects attend to colour. We evaluated whether, in addition to neural areas associated with decisions to specific perceptual properties, areas associated with access to semantic information were activated when tasks demanded processing of the global configuration of pictures. We used two perceptual matching tasks based on the global orientation or on the colour of line drawings. Our results confirmed behavioural data. Activations in the inferior occipital cortex, fusiform and inferior temporal gyri in both tasks (orientation and colour) account for perceptual and structural processing involved in each task. In contrast, activations in the posterior and medial parts of the fusiform gyrus, shown to be involved in explicit semantic judgements, were more pronounced in the orientation-matching task, suggesting that semantic information from the pictures is processed in an implicit way even when not required by the task. Thus, this study suggests that cortical regions usually involved in explicit semantic processing are also activated when implicit processing of objects occurs.
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Affiliation(s)
- D Pins
- Laboratoire de Neurosciences Fonctionnelles et Pathologies, FRE 2726-CNRS, Université Lille 2, Explorations Fonctionnelles de la Vision, CHRU Lille, Hôpital Roger Salengro, 59037 Lille, France.
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30
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Kimberley TJ, Lewis SM, Auerbach EJ, Dorsey LL, Lojovich JM, Carey JR. Electrical stimulation driving functional improvements and cortical changes in subjects with stroke. Exp Brain Res 2003; 154:450-60. [PMID: 14618287 DOI: 10.1007/s00221-003-1695-y] [Citation(s) in RCA: 196] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2003] [Accepted: 08/06/2003] [Indexed: 10/26/2022]
Abstract
It has been proposed that somatosensory stimulation in the form of electromyographically triggered neuromuscular electrical stimulation (NMES) to the peripheral nerve can influence functional measures of motor performance in subjects with stroke and can additionally produce changes in cortical excitability. Using a controlled, double-blind design, we studied the effects of intensive (60 h/3 weeks) treatment at home with NMES compared with a sham treatment, applied to the extensor muscles of the hemiplegic forearm to facilitate hand opening in 16 chronic stroke subjects. We investigated improvement in functional use of the hand and change in cortical activation as measured by functional magnetic resonance imaging (fMRI). Following treatment, subjects improved on measures of grasp and release of objects (Box and Block Test and Jebsen Taylor Hand Function Test [JTHFT]: small objects, stacking, heavy cans), isometric finger extension strength, and self-rated Motor Activity Log (MAL): Amount of Use and How Well score. The sham subjects did not improve on any grasp and release measure or self-rated scale, but did improve on isometric finger extension strength. Importantly, however, following crossover, these subjects improved further in the measure of strength, grasp and release (Box and Block [JTHFT]: page turning), and self-rated MAL: Amount of Use score and How Well score. Using fMRI and a finger-tracking task, an index of cortical intensity in the ipsilateral somatosensory cortex increased significantly from pre-test to post-test following treatment. Cortical activation, as measured by voxel count, did not change. These findings suggest that NMES may have an important role in stimulating cortical sensory areas allowing for improved motor function.
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Affiliation(s)
- Teresa J Kimberley
- Program in Physical Therapy, University of Minnesota, MMC Box 388, MN 55455, Minneapolis, USA.
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31
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Behrmann M, Kimchi R. What does visual agnosia tell us about perceptual organization and its relationship to object perception? J Exp Psychol Hum Percept Perform 2003; 29:19-42. [PMID: 12669745 DOI: 10.1037/0096-1523.29.1.19] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The authors studied 2 patients, S.M. and R.N., to examine perceptual organization and its relationship to object recognition. Both patients had normal, low-level vision and performed simple grouping operations normally but were unable to apprehend a multielement stimulus as a whole. R.N. failed to derive global structure even under optimal stimulus conditions, was less sensitive to grouping by closure, and was more impaired in object recognition than S.M. These findings suggest that perceptual organization involves a multiplicity of processes, some of which are simpler and are instantiated in lower order areas of visual cortex (e.g., collinearity). Other processes are more complex and rely on higher order visual areas (e.g., closure and shape formation). The failure to exploit these latter configural processes adversely affects object recognition.
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32
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Ullsperger M, von Cramon DY, Müller NG. Interactions of focal cortical lesions with error processing: evidence from event-related brain potentials. Neuropsychology 2002; 16:548-61. [PMID: 12382993 DOI: 10.1037/0894-4105.16.4.548] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Electrophysiological and hemodynamic studies have suggested that structures in the vicinity of the anterior cingulate cortex are involved in performance monitoring, particularly in detection of errors. Bidirectional interactions between the frontomedian system involved in performance monitoring and the lateral prefrontal cortex as well as the orbitofrontal cortex have been proposed, but few studies have directly addressed this issue. The authors used a speeded flankers task to investigate error-related event-related potentials in 3 patient groups with different focal cortical lesions. Whereas bilateral frontopolar lesions involving the orbitofrontal cortex as well as temporal lesions did not alter the error-related negativity (ERN), lesions of the lateral frontal cortex resulted in an abolition of the ERN and in a reduction of the error positivity.
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33
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Proverbio AM, Esposito P, Zani A. Early involvement of the temporal area in attentional selection of grating orientation: an ERP study. BRAIN RESEARCH. COGNITIVE BRAIN RESEARCH 2002; 13:139-51. [PMID: 11867258 DOI: 10.1016/s0926-6410(01)00103-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The aim of the present study was to investigate the neural mechanisms of stimulus orientation selection in humans by recording event-related potentials (ERPs) of the brain with a 32-channel montage. Stimuli were isoluminant black-and-white gratings (3 cpd) having an orientation of 50, 70, 90, 110 and 130, randomly presented in the foveal portion (2 of visual angle) of the central visual field. The task consisted in selectively attending and responding to one of the five grating orientations, while ignoring the others. ERP results showed that orientation selection affected neural processing starting already at an early post-stimulus latency. The P1 component (80-140 ms) measured at temporal area, which might well be reflecting the activity of the ventral stream (i.e. 'WHAT' system) of the visual pathways, showed an enhanced amplitude for target orientations. These effects increased with progressive neural processing over time as reflected by selection negativity (SN) and P300 components. In addition, both reaction times (RTs) and ERPs showed a strong 'oblique' effect, very probably reflecting the perceptual predominance of orthogonal versus oblique stimulus orientation in the human visual system: RTs were much faster, and SN and P300 components much larger, to gratings presented vertically than in other orientations.
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Affiliation(s)
- Alice Mado Proverbio
- Department of Psychology, University of Milano-Bicocca, Piazza dell'Ateneo Nuovo, 1, 20126 Milan, Italy.
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34
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Beckmann N, Gentsch C, Baumann D, Bruttel K, Vassout A, Schoeffter P, Loetscher E, Bobadilla M, Perentes E, Rudin M. Current awareness. NMR IN BIOMEDICINE 2001; 14:217-222. [PMID: 11357188 DOI: 10.1002/nbm.669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of NMR in biomedicine. Each bibliography is divided into 9 sections: 1 Books, Reviews ' Symposia; 2 General; 3 Technology; 4 Brain and Nerves; 5 Neuropathology; 6 Cancer; 7 Cardiac, Vascular and Respiratory Systems; 8 Liver, Kidney and Other Organs; 9 Muscle and Orthopaedic. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.
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Affiliation(s)
- N Beckmann
- Core Technologies Area, Novartis Pharma AG, CH-4002 Basel, Switzerland
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