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Costa GN, Schaum M, Duarte JV, Martins R, Duarte IC, Castelhano J, Wibral M, Castelo‐Branco M. Distinct oscillatory patterns differentiate between segregation and integration processes in perceptual grouping. Hum Brain Mapp 2024; 45:e26779. [PMID: 39185735 PMCID: PMC11345702 DOI: 10.1002/hbm.26779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Revised: 05/03/2024] [Accepted: 06/25/2024] [Indexed: 08/27/2024] Open
Abstract
Recently, there has been a resurgence in experimental and conceptual efforts to understand how brain rhythms can serve to organize visual information. Oscillations can provide temporal structure for neuronal processing and form a basis for integrating information across brain areas. Here, we use a bistable paradigm and a data-driven approach to test the hypothesis that oscillatory modulations associate with the integration or segregation of visual elements. Spectral signatures of perception of bound and unbound configurations of visual moving stimuli were studied using magnetoencephalography (MEG) in ambiguous and unambiguous conditions. Using a 2 × 2 design, we were able to isolate correlates from visual integration, either perceptual or stimulus-driven, from attentional and ambiguity-related activity. Two frequency bands were found to be modulated by visual integration: an alpha/beta frequency and a higher frequency gamma-band. Alpha/beta power was increased in several early visual cortical and dorsal visual areas during visual integration, while gamma-band power was surprisingly increased in the extrastriate visual cortex during segregation. This points to an integrative role for alpha/beta activity, likely from top-down signals maintaining a single visual representation. On the other hand, when more representations have to be processed in parallel gamma-band activity is increased, which is at odds with the notion that gamma oscillations are related to perceptual coherence. These modulations were confirmed in intracranial EEG recordings and partially originate from distinct brain areas. Our MEG and stereo-EEG data confirms predictions of binding mechanisms depending on low-frequency activity for long-range integration and for organizing visual processing while refuting a straightforward correlation between gamma-activity and perceptual binding. PRACTITIONER POINTS: Distinct neurophysiological signals underlie competing bistable percepts. Increased alpha/beta activity correlate with visual integration while gamma correlates with segmentation. Ambiguous percepts drive alpha/beta activity in the posterior cingulate cortex.
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Affiliation(s)
- Gabriel Nascimento Costa
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
- Present address:
Trinity College DublinDublinIreland
| | - Michael Schaum
- MEG Unit, Brain Imaging CenterGoethe UniversityFrankfurt/MainGermany
| | - João Valente Duarte
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
| | - Ricardo Martins
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
| | - Isabel Catarina Duarte
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
| | - João Castelhano
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
| | - Michael Wibral
- MEG Unit, Brain Imaging CenterGoethe UniversityFrankfurt/MainGermany
- Campus Institute for Dynamics of Biological NetworksGeorg‐August UniversityGöttingenGermany
| | - Miguel Castelo‐Branco
- Institute for Biomedical Imaging and Translational Research (CIBIT)University of CoimbraCoimbraPortugal
- Institute of Nuclear Sciences Applied to Health (ICNAS)University of CoimbraCoimbraPortugal
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2
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Di Dona G, Ronconi L. Beta oscillations in vision: a (preconscious) neural mechanism for the dorsal visual stream? Front Psychol 2023; 14:1296483. [PMID: 38155693 PMCID: PMC10753839 DOI: 10.3389/fpsyg.2023.1296483] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 11/15/2023] [Indexed: 12/30/2023] Open
Abstract
Neural oscillations in alpha (8-12 Hz) and beta (13-30 Hz) frequency bands are thought to reflect feedback/reentrant loops and large-scale cortical interactions. In the last decades a main effort has been made in linking perception with alpha-band oscillations, with converging evidence showing that alpha oscillations have a key role in the temporal and featural binding of visual input, configuring the alpha rhythm a key determinant of conscious visual experience. Less attention has been historically dedicated to link beta oscillations and visual processing. Nonetheless, increasing studies report that task conditions that require to segregate/integrate stimuli in space, to disentangle local/global shapes, to spatially reorganize visual inputs, and to achieve motion perception or form-motion integration, rely on the activity of beta oscillations, with a main hub in parietal areas. In the present review, we summarize the evidence linking oscillations within the beta band and visual perception. We propose that beta oscillations represent a neural code that supports the functionality of the magnocellular-dorsal (M-D) visual pathway, serving as a fast primary neural code to exert top-down influences on the slower parvocellular-ventral visual pathway activity. Such M-D-related beta activity is proposed to act mainly pre-consciously, providing the spatial coordinates of vision and guiding the conscious extraction of objects identity that are achieved with slower alpha rhythms in ventral areas. Finally, within this new theoretical framework, we discuss the potential role of M-D-related beta oscillations in visuo-spatial attention, oculo-motor behavior and reading (dis)abilities.
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Affiliation(s)
- Giuseppe Di Dona
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
| | - Luca Ronconi
- Division of Neuroscience, IRCCS San Raffaele Scientific Institute, Milan, Italy
- School of Psychology, Vita-Salute San Raffaele University, Milan, Italy
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3
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Wu H, Zuo Z, Yuan Z, Zhou T, Zhuo Y, Zheng N, Chen B. Neural representation of gestalt grouping and attention effect in human visual cortex. J Neurosci Methods 2023; 399:109980. [PMID: 37783351 DOI: 10.1016/j.jneumeth.2023.109980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 08/29/2023] [Accepted: 09/29/2023] [Indexed: 10/04/2023]
Abstract
BACKGROUND The brain aggregates meaningless local sensory elements to form meaningful global patterns in a process called perceptual grouping. Current brain imaging studies have found that neural activities in V1 are modulated during visual grouping. However, how grouping is represented in each of the early visual areas, and how attention alters these representations, is still unknown. NEW METHOD We adopted MVPA to decode the specific content of perceptual grouping by comparing neural activity patterns between gratings and dot lattice stimuli which can be grouped with proximity law. Furthermore, we quantified the grouping effect by defining the strength of grouping, and assessed the effect of attention on grouping. RESULTS We found that activity patterns to proximity grouped stimuli in early visual areas resemble these to grating stimuli with the same orientations. This similarity exists even when there is no attention focused on the stimuli. The results also showed a progressive increase of representational strength of grouping from V1 to V3, and attention modulation to grouping is only significant in V3 among all the visual areas. COMPARISON WITH EXISTING METHODS Most of the previous work on perceptual grouping has focused on how activity amplitudes are modulated by grouping. Using MVPA, the present work successfully decoded the contents of neural activity patterns corresponding to proximity grouping stimuli, thus shed light on the availability of content-decoding approach in the research on perceptual grouping. CONCLUSIONS Our work found that the content of the neural activity patterns during perceptual grouping can be decoded in the early visual areas under both attended and unattended task, and provide novel evidence that there is a cascade processing for proximity grouping through V1 to V3. The strength of grouping was larger in V3 than in any other visual areas, and the attention modulation to the strength of grouping was only significant in V3 among all the visual areas, implying that V3 plays an important role in proximity grouping.
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Affiliation(s)
- Hao Wu
- School of Electrical Engineering, Xi'an University of Technology, Xi'an, Shaanxi 710048, China
| | - Zhentao Zuo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China.
| | - Zejian Yuan
- National Key Laboratory of Human-Machine Hybrid Augmented Intelligence, Xi'an, Shaanxi 710049, China; Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Tiangang Zhou
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Yan Zhuo
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of the Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing, China
| | - Nanning Zheng
- National Key Laboratory of Human-Machine Hybrid Augmented Intelligence, Xi'an, Shaanxi 710049, China; Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China
| | - Badong Chen
- National Key Laboratory of Human-Machine Hybrid Augmented Intelligence, Xi'an, Shaanxi 710049, China; Institute of Artificial Intelligence and Robotics, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
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4
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Lhotka M, Ischebeck A, Helmlinger B, Zaretskaya N. No common factor for illusory percepts, but a link between pareidolia and delusion tendency: A test of predictive coding theory. Front Psychol 2023; 13:1067985. [PMID: 36798645 PMCID: PMC9928206 DOI: 10.3389/fpsyg.2022.1067985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Accepted: 12/07/2022] [Indexed: 01/06/2023] Open
Abstract
Predictive coding theory is an influential view of perception and cognition. It proposes that subjective experience of the sensory information results from a comparison between the sensory input and the top-down prediction about this input, the latter being critical for shaping the final perceptual outcome. The theory is able to explain a wide range of phenomena extending from sensory experiences such as visual illusions to complex pathological states such as hallucinations and psychosis. In the current study we aimed at testing the proposed connection between different phenomena explained by the predictive coding theory by measuring the manifestation of top-down predictions at progressing levels of complexity, starting from bistable visual illusions (alternating subjective experience of the same sensory input) and pareidolias (alternative meaningful interpretation of the sensory input) to self-reports of hallucinations and delusional ideations in everyday life. Examining the correlation structure of these measures in 82 adult healthy subjects revealed a positive association between pareidolia proneness and a tendency for delusional ideations, yet without any relationship to bistable illusions. These results show that only a subset of the phenomena that are explained by the predictive coding theory can be attributed to one common underlying factor. Our findings thus support the hierarchical view of predictive processing with independent top-down effects at the sensory and cognitive levels.
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Affiliation(s)
- Magdalena Lhotka
- Department of Cognitive Psychology and Neuroscience, Institute of Psychology, University of Graz, Graz, Austria
| | - Anja Ischebeck
- Department of Cognitive Psychology and Neuroscience, Institute of Psychology, University of Graz, Graz, Austria,BioTechMed-Graz, Graz, Austria
| | - Birgit Helmlinger
- Department of Cognitive Psychology and Neuroscience, Institute of Psychology, University of Graz, Graz, Austria,BioTechMed-Graz, Graz, Austria
| | - Natalia Zaretskaya
- Department of Cognitive Psychology and Neuroscience, Institute of Psychology, University of Graz, Graz, Austria,BioTechMed-Graz, Graz, Austria,*Correspondence: Natalia Zaretskaya, ✉
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5
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Hua L, Gao F, Leong C, Yuan Z. Neural decoding dissociates perceptual grouping between proximity and similarity in visual perception. Cereb Cortex 2022; 33:3803-3815. [PMID: 35973163 DOI: 10.1093/cercor/bhac308] [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: 04/28/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 11/13/2022] Open
Abstract
Unlike single grouping principle, cognitive neural mechanism underlying the dissociation across two or more grouping principles is still unclear. In this study, a dimotif lattice paradigm that can adjust the strength of one grouping principle was used to inspect how, when, and where the processing of two grouping principles (proximity and similarity) were carried out in human brain. Our psychophysical findings demonstrated that similarity grouping effect was enhanced with reduced proximity effect when the grouping cues of proximity and similarity were presented simultaneously. Meanwhile, EEG decoding was performed to reveal the specific cognitive patterns involved in each principle by using time-resolved MVPA. More importantly, the onsets of dissociation between 2 grouping principles coincided within 3 time windows: the early-stage proximity-defined local visual element arrangement in middle occipital cortex, the middle-stage processing for feature selection modulating low-level visual cortex such as inferior occipital cortex and fusiform cortex, and the high-level cognitive integration to make decisions for specific grouping preference in the parietal areas. In addition, it was discovered that the brain responses were highly correlated with behavioral grouping. Therefore, our study provides direct evidence for a link between the human perceptual space of grouping decision-making and neural space of brain activation patterns.
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Affiliation(s)
- Lin Hua
- Centre for Cognitive and Brain Sciences, N21 Research Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China.,Faculty of Health Sciences, E12 Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China
| | - Fei Gao
- Centre for Cognitive and Brain Sciences, N21 Research Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China
| | - Chantat Leong
- Centre for Cognitive and Brain Sciences, N21 Research Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China.,Faculty of Health Sciences, E12 Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China
| | - Zhen Yuan
- Centre for Cognitive and Brain Sciences, N21 Research Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China.,Faculty of Health Sciences, E12 Building, University of Macau, Avenida da Universidade, Taipa, Macau SAR 999078, China
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6
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Wilding M, Körner C, Ischebeck A, Zaretskaya N. Increased insula activity precedes the formation of subjective illusory Gestalt. Neuroimage 2022; 257:119289. [PMID: 35537599 DOI: 10.1016/j.neuroimage.2022.119289] [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: 01/13/2022] [Revised: 03/26/2022] [Accepted: 05/06/2022] [Indexed: 11/29/2022] Open
Abstract
The constructive nature of human perception sometimes leads us to perceiving rather complex impressions from simple sensory input: for example, recognizing animal contours in cloud formations or seeing living creatures in shadows of objects. A special type of bistable stimuli gives us a rare opportunity to study the neural mechanisms behind this process. Such stimuli can be visually interpreted either as simple or as more complex illusory content on the basis of the same sensory input. Previous studies demonstrated increased activity in the superior parietal cortex during the perception of an illusory Gestalt impression compared to a simpler interpretation. Here, we examined the role of slow fluctuations of resting-state fMRI activity in shaping the subsequent illusory interpretation by investigating activity related to the illusory Gestalt not only during, but also prior to its perception. We presented 31 participants with a bistable motion stimulus, which can be perceived either as four moving dot pairs (local) or two moving illusory squares (global). fMRI was used to measure brain activity in a slow event-related design. We observed stronger IPS and putamen responses to the stimulus when participants perceived the global interpretation compared to the local, confirming the findings of previous studies. Most importantly, we also observed that the global stimulus interpretation was preceded by an increased activity of the bilateral dorsal insula, which is known to process saliency and gate information for conscious access. Our data suggest an important role of the dorsal insula in shaping complex illusory interpretations of the sensory input.
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Affiliation(s)
- Marilena Wilding
- Institute of Psychology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria.
| | - Christof Körner
- Institute of Psychology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria
| | - Anja Ischebeck
- Institute of Psychology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria
| | - Natalia Zaretskaya
- Institute of Psychology, University of Graz, Universitätsplatz 2, 8010 Graz, Austria; BioTechMed-Graz, Mozartgasse 12, 8010 Graz, Austria.
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7
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van Kemenade BM, Wilbertz G, Müller A, Sterzer P. Non-stimulated regions in early visual cortex encode the contents of conscious visual perception. Hum Brain Mapp 2021; 43:1394-1402. [PMID: 34862702 PMCID: PMC8837582 DOI: 10.1002/hbm.25731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/07/2021] [Accepted: 11/08/2021] [Indexed: 11/11/2022] Open
Abstract
Predictions shape our perception. The theory of predictive processing poses that our brains make sense of incoming sensory input by generating predictions, which are sent back from higher to lower levels of the processing hierarchy. These predictions are based on our internal model of the world and enable inferences about the hidden causes of the sensory input data. It has been proposed that conscious perception corresponds to the currently most probable internal model of the world. Accordingly, predictions influencing conscious perception should be fed back from higher to lower levels of the processing hierarchy. Here, we used functional magnetic resonance imaging and multivoxel pattern analysis to show that non‐stimulated regions of early visual areas contain information about the conscious perception of an ambiguous visual stimulus. These results indicate that early sensory cortices in the human brain receive predictive feedback signals that reflect the current contents of conscious perception.
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Affiliation(s)
- Bianca M van Kemenade
- Centre for Cognitive Neuroimaging, Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, UK.,Department of Psychiatry and Psychotherapy, Philipps-University Marburg, Marburg, Germany.,Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Berlin, Germany
| | - Gregor Wilbertz
- Department of Psychology, Freie Universität Berlin, Berlin, Germany.,Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Berlin, Germany
| | - Annalena Müller
- Department of Experimental and Biological Psychology, University of Potsdam, Potsdam, Germany.,Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Berlin, Germany
| | - Philipp Sterzer
- Department of Psychiatry and Psychotherapy, Charité Campus Mitte, Berlin, Germany
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8
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Boswell AM, Kohler PJ, McCarthy JD, Caplovitz GP. Perceived group size is determined by the centroids of the component elements. J Vis 2021; 21:1. [PMID: 34851391 PMCID: PMC8648053 DOI: 10.1167/jov.21.13.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
To accomplish the deceptively simple task of perceiving the size of objects in the visual scene, the visual system combines information about the retinal size of the object with several other cues, including perceived distance, relative size, and prior knowledge. When local component elements are perceptually grouped to form objects, the task is further complicated because a grouped object does not have a continuous contour from which retinal size can be estimated. Here, we investigate how the visual system solves this problem and makes it possible for observers to judge the size of perceptually grouped objects. We systematically vary the shape and orientation of the component elements in a two-alternative forced-choice task and find that the perceived size of the array of component objects can be almost perfectly predicted from the distance between the centroids of the component elements and the center of the array. This is true whether the global contour forms a circle or a square. When elements were positioned such that the centroids along the global contour were at different distances from the center, perceived size was based on the average distance. These results indicate that perceived size does not depend on the size of individual elements, and that smooth contours formed by the outer edges of the component elements are not used to estimate size. The current study adds to a growing literature highlighting the importance of centroids in visual perception and may have implications for how size is estimated for ensembles of different objects.
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Affiliation(s)
| | - Peter J Kohler
- Department of Psychology, York University, Toronto, Ontario, Canada.,Centre for Vision Research, York University, Toronto, Ontario, Canada.,
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9
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Zooming-in on higher-level vision: High-resolution fMRI for understanding visual perception and awareness. Prog Neurobiol 2021; 207:101998. [PMID: 33497652 DOI: 10.1016/j.pneurobio.2021.101998] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Revised: 11/11/2020] [Accepted: 01/16/2021] [Indexed: 12/24/2022]
Abstract
One of the central questions in visual neuroscience is how the sparse retinal signals leaving our eyes are transformed into a rich subjective visual experience of the world. Invasive physiology studies, which offers the highest spatial resolution, have revealed many facts about the processing of simple visual features like contrast, color, and orientation, focusing on the early visual areas. At the same time, standard human fMRI studies with comparably coarser spatial resolution have revealed more complex, functionally specialized, and category-selective responses in higher visual areas. Although the visual system is the best understood among the sensory modalities, these two areas of research remain largely segregated. High-resolution fMRI opens up a possibility for linking them. On the one hand, it allows studying how the higher-level visual functions affect the fine-scale activity in early visual areas. On the other hand, it allows discovering the fine-scale functional organization of higher visual areas and exploring their functional connectivity with visual areas lower in the hierarchy. In this review, I will discuss examples of successful work undertaken in these directions using high-resolution fMRI and discuss where this method could be applied in the future to advance our understanding of the complexity of higher-level visual processing.
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10
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Foster C, Bülthoff I, Bartels A, Zhao M. Investigating holistic face processing within and outside of face-responsive brain regions. Neuroimage 2020; 226:117565. [PMID: 33221444 DOI: 10.1016/j.neuroimage.2020.117565] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Revised: 09/18/2020] [Accepted: 11/10/2020] [Indexed: 10/23/2022] Open
Abstract
It has been shown that human faces are processed holistically (i.e. as indecomposable wholes, rather than by their component parts) and this holistic face processing is linked to brain activity in face-responsive brain regions. Although several brain regions outside of the face-responsive network are also sensitive to relational processing and perceptual grouping, whether these non-face-responsive regions contribute to holistic processing remains unclear. Here, we investigated holistic face processing in the composite face paradigm both within and outside of face-responsive brain regions. We recorded participants' brain activity using fMRI while they performed a composite face task. Behavioural results indicate that participants tend to judge the same top face halves as different when they are aligned with different bottom face halves but not when they are misaligned, demonstrating a composite face effect. Neuroimaging results revealed significant differences in responses to aligned and misaligned faces in the lateral occipital complex (LOC), and trends in the anterior part of the fusiform face area (FFA2) and transverse occipital sulcus (TOS), suggesting that these regions are sensitive to holistic versus part-based face processing. Furthermore, the retrosplenial cortex (RSC) and the parahippocampal place area (PPA) showed a pattern of neural activity consistent with a holistic representation of face identity, which also correlated with the strength of the behavioural composite face effect. These results suggest that neural activity in brain regions both within and outside of the face-responsive network contributes to the composite-face effect.
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Affiliation(s)
- Celia Foster
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany; International Max Planck Research School for Cognitive and Systems Neuroscience, University of Tübingen, Tübingen, Germany.
| | | | - Andreas Bartels
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany; Centre for Integrative Neuroscience, Tübingen, Germany; Department of Psychology, University of Tübingen, Tübingen, Germany; Bernstein Center for Computational Neuroscience, Tübingen, Germany
| | - Mintao Zhao
- Max Planck Institute for Biological Cybernetics, Tübingen, Germany; School of Psychology, University of East Anglia, Norwich, UK.
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11
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Stoll S, Finlayson NJ, Schwarzkopf DS. Topographic signatures of global object perception in human visual cortex. Neuroimage 2020; 220:116926. [PMID: 32442640 PMCID: PMC7573540 DOI: 10.1016/j.neuroimage.2020.116926] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 01/12/2023] Open
Abstract
Our visual system readily groups dynamic fragmented input into global objects. How the brain represents global object perception remains however unclear. To address this question, we recorded brain responses using functional magnetic resonance imaging whilst observers viewed a dynamic bistable stimulus that could either be perceived globally (i.e., as a grouped and coherently moving shape) or locally (i.e., as ungrouped and incoherently moving elements). We further estimated population receptive fields and used these to back-project the brain activity measured during stimulus perception into visual space via a searchlight procedure. Global perception resulted in universal suppression of responses in lower visual cortex accompanied by wide-spread enhancement in higher object-sensitive cortex. However, follow-up experiments indicated that higher object-sensitive cortex is suppressed if global perception lacks shape grouping, and that grouping-related suppression can be diffusely confined to stimulated sites and accompanied by background enhancement once stimulus size is reduced. These results speak to a non-generic involvement of higher object-sensitive cortex in perceptual grouping and point to an enhancement-suppression mechanism mediating the perception of figure and ground. Lower visual cortex activity to grouped vs ungrouped dynamic stimuli is suppressed. When grouping a shape, activity in higher object-sensitive cortex is enhanced. Without shape grouping, activity in higher object-sensitive cortex is suppressed. Grouping-related suppression can be diffusely confined to stimulated cortical sites.
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Affiliation(s)
- Susanne Stoll
- Experimental Psychology, University College London, 26 Bedford Way, London, WC1H 0AP, UK.
| | - Nonie J Finlayson
- Experimental Psychology, University College London, 26 Bedford Way, London, WC1H 0AP, UK
| | - D Samuel Schwarzkopf
- Experimental Psychology, University College London, 26 Bedford Way, London, WC1H 0AP, UK
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12
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Bi W, Jin P, Nienborg H, Xiao B. Manipulating patterns of dynamic deformation elicits the impression of cloth with varying stiffness. J Vis 2019; 19:18. [DOI: 10.1167/19.5.18] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Wenyan Bi
- Department of Computer Science, American University, Washington, DC, USA
- ://sites.google.com/site/wenyanbi0819
| | - Peiran Jin
- Department of Physics, Georgetown University, Washington, DC, USA
| | - Hendrikje Nienborg
- Centre for Integrative Neuroscience, University of Tübingen, Tübingen, Germany
- ://www.cin.uni-tuebingen.de/research/research-groups/junior-research-groups/neurophysiology-of-visual-and-decision-processes/staff/person-detail/dr-hendrikje-nienborg.html
| | - Bei Xiao
- Department of Computer Science, American University, Washington, DC, USA
- ://sites.google.com/site/beixiao/
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13
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O'Rawe JF, Huang AS, Klein DN, Leung HC. Posterior parietal influences on visual network specialization during development: An fMRI study of functional connectivity in children ages 9 to 12. Neuropsychologia 2019; 127:158-170. [PMID: 30849407 DOI: 10.1016/j.neuropsychologia.2019.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2018] [Revised: 02/20/2019] [Accepted: 03/04/2019] [Indexed: 11/27/2022]
Abstract
Visual processing in the primate brain is highly organized along the ventral visual pathway, although it is still unclear how categorical selectivity emerges in this system. While many theories have attempted to explain the pattern of visual specialization within the ventral occipital and temporal areas, the biased connectivity hypothesis provides a framework which postulates extrinsic connectivity as a potential mechanism in shaping the development of category selectivity. As the posterior parietal cortex plays a central role in visual attention, we examined whether the pattern of parietal connectivity with the face and scene processing regions is closely linked with the functional properties of these two visually selective networks in a cohort of 60 children ages 9 to 12. Functionally localized face and scene selective regions were used in deriving each visual network's resting-state functional connectivity. The children's face and scene processing networks appeared to show a weak network segregation during resting state, which was confirmed when compared to that of a group of gender and handedness matched adults. Parietal regions of these children showed differential connectivity with the face and scene networks, and the extent of this differential parietal-visual connectivity predicted individual differences in the degree of segregation between the two visual networks, which in turn predicted individual differences in visual perception performance. Finally, the pattern of parietal connectivity with the face processing network also predicted the foci of face-related activation in the right fusiform gyrus across children. These findings provide evidence that extrinsic connectivity with regions such as the posterior parietal cortex may have important implications in the development of specialized visual processing networks.
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Affiliation(s)
| | - Anna S Huang
- Department of Psychology, Stony Brook University, USA
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