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Kavšek M. Perception of illusory contours in children and adults: An eye-tracking study. Atten Percept Psychophys 2023:10.3758/s13414-023-02832-z. [PMID: 38157202 DOI: 10.3758/s13414-023-02832-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/12/2023] [Indexed: 01/03/2024]
Abstract
The eye-tracking study investigated the perception of subjective Kanizsa and Ehrenstein figures in adults and in children aged 3-4, 5-6, 7-8, and 9-11 years of age. More specifically, the distribution of looking at the inner stimulus part versus the inducing elements was measured for illusory figures, figures with real contours, and control displays. It was hypothesized that longer looking at the inner area of the illusory figures indicates global contour interpolation, whereas longer looking at the inducing elements indicates a local processing mode. According to the results, participants of all ages looked longer at the illusory Kanizsa and Ehrenstein contours than at the figures' inducing elements. However, performance was lowest in the children aged 3-4 years and increased during the preschool period. Moreover, the illusory contour displays elicited comparable visual responses as did the real contour displays. The use of the control displays that contained no contour information ensured that the participants' looking behavior was not driven by a spontaneous tendency to attend to the inner stimulus parts. The study confirms the view that sensitivity to illusory contours emerges very early in life.
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Affiliation(s)
- Michael Kavšek
- Department of Psychology, University of Bonn, Kaiser-Karl-Ring 9, 53111, Bonn, Germany.
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2
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Cheng FL, Horikawa T, Majima K, Tanaka M, Abdelhack M, Aoki SC, Hirano J, Kamitani Y. Reconstructing visual illusory experiences from human brain activity. SCIENCE ADVANCES 2023; 9:eadj3906. [PMID: 37967184 PMCID: PMC10651116 DOI: 10.1126/sciadv.adj3906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 10/13/2023] [Indexed: 11/17/2023]
Abstract
Visual illusions provide valuable insights into the brain's interpretation of the world given sensory inputs. However, the precise manner in which brain activity translates into illusory experiences remains largely unknown. Here, we leverage a brain decoding technique combined with deep neural network (DNN) representations to reconstruct illusory percepts as images from brain activity. The reconstruction model was trained on natural images to establish a link between brain activity and perceptual features and then tested on two types of illusions: illusory lines and neon color spreading. Reconstructions revealed lines and colors consistent with illusory experiences, which varied across the source visual cortical areas. This framework offers a way to materialize subjective experiences, shedding light on the brain's internal representations of the world.
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Affiliation(s)
- Fan L. Cheng
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
- ATR Computational Neuroscience Laboratories, Soraku, Kyoto 619-0288, Japan
| | - Tomoyasu Horikawa
- ATR Computational Neuroscience Laboratories, Soraku, Kyoto 619-0288, Japan
| | - Kei Majima
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Misato Tanaka
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Mohamed Abdelhack
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Shuntaro C. Aoki
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Jin Hirano
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yukiyasu Kamitani
- Graduate School of Informatics, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
- ATR Computational Neuroscience Laboratories, Soraku, Kyoto 619-0288, Japan
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3
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von Gal A, Boccia M, Nori R, Verde P, Giannini AM, Piccardi L. Neural networks underlying visual illusions: An activation likelihood estimation meta-analysis. Neuroimage 2023; 279:120335. [PMID: 37591478 DOI: 10.1016/j.neuroimage.2023.120335] [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: 04/13/2023] [Revised: 07/05/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023] Open
Abstract
Visual illusions have long been used to study visual perception and contextual integration. Neuroimaging studies employ illusions to identify the brain regions involved in visual perception and how they interact. We conducted an Activation Likelihood Estimation (ALE) meta-analysis and meta-analytic connectivity modeling on fMRI studies using static and motion illusions to reveal the neural signatures of illusory processing and to investigate the degree to which different areas are commonly recruited in perceptual inference. The resulting networks encompass ventral and dorsal regions, including the inferior and middle occipital cortices bilaterally in both types of illusions. The static and motion illusion networks selectively included the right posterior parietal cortex and the ventral premotor cortex respectively. Overall, these results describe a network of areas crucially involved in perceptual inference relying on feed-back and feed-forward interactions between areas of the ventral and dorsal visual pathways. The same network is proposed to be involved in hallucinogenic symptoms characteristic of schizophrenia and other disorders, with crucial implications in the use of illusions as biomarkers.
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Affiliation(s)
| | - Maddalena Boccia
- Department of Psychology, Sapienza University of Rome, Rome, Italy; Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Raffaella Nori
- Department of Psychology, University of Bologna, Bologna, Italy
| | - Paola Verde
- Italian Air Force Experimental Flight Center, Aerospace Medicine Department, Pratica di Mare, Rome, Italy
| | | | - Laura Piccardi
- Department of Psychology, Sapienza University of Rome, Rome, Italy; San Raffaele Cassino Hospital, Cassino, FR, Italy
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4
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Shin H, Ogando MB, Abdeladim L, Durand S, Belski H, Cabasco H, Loefler H, Bawany A, Hardcastle B, Wilkes J, Nguyen K, Suarez L, Johnson T, Han W, Ouellette B, Grasso C, Swapp J, Ha V, Young A, Caldejon S, Williford A, Groblewski P, Olsen S, Kiselycznyk C, Lecoq J, Adesnik H. Recurrent pattern completion drives the neocortical representation of sensory inference. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.05.543698. [PMID: 37333175 PMCID: PMC10274729 DOI: 10.1101/2023.06.05.543698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
When sensory information is incomplete or ambiguous, the brain relies on prior expectations to infer perceptual objects. Despite the centrality of this process to perception, the neural mechanism of sensory inference is not known. Illusory contours (ICs) are key tools to study sensory inference because they contain edges or objects that are implied only by their spatial context. Using cellular resolution, mesoscale two-photon calcium imaging and multi-Neuropixels recordings in the mouse visual cortex, we identified a sparse subset of neurons in the primary visual cortex (V1) and higher visual areas that respond emergently to ICs. We found that these highly selective 'IC-encoders' mediate the neural representation of IC inference. Strikingly, selective activation of these neurons using two-photon holographic optogenetics was sufficient to recreate IC representation in the rest of the V1 network, in the absence of any visual stimulus. This outlines a model in which primary sensory cortex facilitates sensory inference by selectively strengthening input patterns that match prior expectations through local, recurrent circuitry. Our data thus suggest a clear computational purpose for recurrence in the generation of holistic percepts under sensory ambiguity. More generally, selective reinforcement of top-down predictions by pattern-completing recurrent circuits in lower sensory cortices may constitute a key step in sensory inference.
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Affiliation(s)
- Hyeyoung Shin
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- Present Address: School of Biological Sciences, Seoul National University, Seoul, Republic of Korea
| | - Mora B Ogando
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Lamiae Abdeladim
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
| | | | - Hannah Belski
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Henry Loefler
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Ahad Bawany
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Josh Wilkes
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Lucas Suarez
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Tye Johnson
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Warren Han
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Ben Ouellette
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Conor Grasso
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Jackie Swapp
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Vivian Ha
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Ahrial Young
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Ali Williford
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Shawn Olsen
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | | | - Jerome Lecoq
- Allen Institute, Mindscope Program, Seattle, WA, USA
| | - Hillel Adesnik
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, USA
- The Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA, USA
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5
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Knight EJ, Freedman EG, Myers EJ, Berruti AS, Oakes LA, Cao CZ, Molholm S, Foxe JJ. Severely Attenuated Visual Feedback Processing in Children on the Autism Spectrum. J Neurosci 2023; 43:2424-2438. [PMID: 36859306 PMCID: PMC10072299 DOI: 10.1523/jneurosci.1192-22.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 02/07/2023] [Accepted: 02/10/2023] [Indexed: 03/03/2023] Open
Abstract
Individuals on the autism spectrum often exhibit atypicality in their sensory perception, but the neural underpinnings of these perceptual differences remain incompletely understood. One proposed mechanism is an imbalance in higher-order feedback re-entrant inputs to early sensory cortices during sensory perception, leading to increased propensity to focus on local object features over global context. We explored this theory by measuring visual evoked potentials during contour integration as considerable work has revealed that these processes are largely driven by feedback inputs from higher-order ventral visual stream regions. We tested the hypothesis that autistic individuals would have attenuated evoked responses to illusory contours compared with neurotypical controls. Electrophysiology was acquired while 29 autistic and 31 neurotypical children (7-17 years old, inclusive of both males and females) passively viewed a random series of Kanizsa figure stimuli, each consisting of four inducers that were aligned either at random rotational angles or such that contour integration would form an illusory square. Autistic children demonstrated attenuated automatic contour integration over lateral occipital regions relative to neurotypical controls. The data are discussed in terms of the role of predictive feedback processes on perception of global stimulus features and the notion that weakened "priors" may play a role in the visual processing anomalies seen in autism.SIGNIFICANCE STATEMENT Children on the autism spectrum differ from typically developing children in many aspects of their processing of sensory stimuli. One proposed mechanism for these differences is an imbalance in higher-order feedback to primary sensory regions, leading to an increased focus on local object features rather than global context. However, systematic investigation of these feedback mechanisms remains limited. Using EEG and a visual illusion paradigm that is highly dependent on intact feedback processing, we demonstrated significant disruptions to visual feedback processing in children with autism. This provides much needed experimental evidence that advances our understanding of the contribution of feedback processing to visual perception in autism spectrum disorder.
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Affiliation(s)
- Emily J Knight
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
- Development and Behavioral Pediatrics, Golisano Children's Hospital, University of Rochester, Rochester, New York 14642
| | - Edward G Freedman
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Evan J Myers
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Alaina S Berruti
- Cognitive Neurophysiology Laboratory, Department of Pediatrics and Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Leona A Oakes
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
- Cognitive Neurophysiology Laboratory, Department of Pediatrics and Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Cody Zhewei Cao
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Sophie Molholm
- Cognitive Neurophysiology Laboratory, Department of Pediatrics and Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - John J Foxe
- Frederick J. and Marion A. Schindler Cognitive Neurophysiology Laboratory, Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
- Cognitive Neurophysiology Laboratory, Department of Pediatrics and Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
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6
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Fan J, Zeng Y. Challenging deep learning models with image distortion based on the abutting grating illusion. PATTERNS (NEW YORK, N.Y.) 2023; 4:100695. [PMID: 36960449 PMCID: PMC10028432 DOI: 10.1016/j.patter.2023.100695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/07/2022] [Accepted: 02/01/2023] [Indexed: 03/06/2023]
Abstract
Even state-of-the-art deep learning models lack fundamental abilities compared with humans. While many image distortions have been proposed to compare deep learning with humans, they depend on mathematical transformations instead of human cognitive functions. Here, we propose an image distortion based on the abutting grating illusion, which is a phenomenon discovered in humans and animals. The distortion generates illusory contour perception using line gratings abutting each other. We applied the method to MNIST, high-resolution MNIST, and "16-class-ImageNet" silhouettes. Many models, including models trained from scratch and 109 models pretrained with ImageNet or various data augmentation techniques, were tested. Our results show that abutting grating distortion is challenging even for state-of-the-art deep learning models. We discovered that DeepAugment models outperformed other pretrained models. Visualization of early layers indicates that better-performing models exhibit the endstopping property, which is consistent with neuroscience discoveries. Twenty-four human subjects classified distorted samples to validate the distortion.
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Affiliation(s)
- Jinyu Fan
- Brain-inspired Cognitive Intelligence Lab, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Yi Zeng
- Brain-inspired Cognitive Intelligence Lab, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
- National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
- School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
- School of Artificial Intelligence, University of Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
- Corresponding author
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7
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Kirchberger L, Mukherjee S, Self MW, Roelfsema PR. Contextual drive of neuronal responses in mouse V1 in the absence of feedforward input. SCIENCE ADVANCES 2023; 9:eadd2498. [PMID: 36662858 PMCID: PMC9858514 DOI: 10.1126/sciadv.add2498] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 12/19/2022] [Indexed: 06/17/2023]
Abstract
Neurons in the primary visual cortex (V1) respond to stimuli in their receptive field (RF), which is defined by the feedforward input from the retina. However, V1 neurons are also sensitive to contextual information outside their RF, even if the RF itself is unstimulated. Here, we examined the cortical circuits for V1 contextual responses to gray disks superimposed on different backgrounds. Contextual responses began late and were strongest in the feedback-recipient layers of V1. They differed between the three main classes of inhibitory neurons, with particularly strong contextual drive of VIP neurons, indicating a contribution of disinhibitory circuits to contextual drive. Contextual drive was strongest when the gray disk was perceived as figure, occluding its background, rather than a hole. Our results link contextual drive in V1 to perceptual organization and provide previously unknown insight into how recurrent processing shapes the response of sensory neurons to facilitate figure perception.
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Affiliation(s)
- Lisa Kirchberger
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, Netherlands
| | - Sreedeep Mukherjee
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, Netherlands
| | - Matthew W. Self
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, Netherlands
| | - Pieter R. Roelfsema
- Department of Vision and Cognition, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, Netherlands
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, VU University, Amsterdam, Netherlands
- Department of Psychiatry, Academic Medical Center, Amsterdam, Netherlands
- Laboratory of Visual Brain Therapy, Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche Scientifique, Institut de la Vision, Paris F-75012, France
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8
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Khona M, Fiete IR. Attractor and integrator networks in the brain. Nat Rev Neurosci 2022; 23:744-766. [DOI: 10.1038/s41583-022-00642-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2022] [Indexed: 11/06/2022]
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9
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Chen YD, Kaestner M, Norcia AM. Cognitive penetrability of scene representations based on horizontal image disparities. Sci Rep 2022; 12:17902. [PMID: 36284130 PMCID: PMC9596438 DOI: 10.1038/s41598-022-22670-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 10/18/2022] [Indexed: 01/20/2023] Open
Abstract
The structure of natural scenes is signaled by many visual cues. Principal amongst them are the binocular disparities created by the laterally separated viewpoints of the two eyes. Disparity cues are believed to be processed hierarchically, first in terms of local measurements of absolute disparity and second in terms of more global measurements of relative disparity that allow extraction of the depth structure of a scene. Psychophysical and oculomotor studies have suggested that relative disparities are particularly relevant to perception, whilst absolute disparities are not. Here, we compare neural responses to stimuli that isolate the absolute disparity cue with stimuli that contain additional relative disparity cues, using the high temporal resolution of EEG to determine the temporal order of absolute and relative disparity processing. By varying the observers' task, we assess the extent to which each cue is cognitively penetrable. We find that absolute disparity is extracted before relative disparity, and that task effects arise only at or after the extraction of relative disparity. Our results indicate a hierarchy of disparity processing stages leading to the formation of a proto-object representation upon which higher cognitive processes can act.
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Affiliation(s)
- Yulan D Chen
- Department of Psychology, Stanford University, 450 Jane Stanford Way, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute, Stanford University, 290 Jane Stanford Way, Stanford, CA, USA
| | - Milena Kaestner
- Department of Psychology, Stanford University, 450 Jane Stanford Way, Stanford, CA, USA.
- Wu-Tsai Neuroscience Institute, Stanford University, 290 Jane Stanford Way, Stanford, CA, USA.
| | - Anthony M Norcia
- Department of Psychology, Stanford University, 450 Jane Stanford Way, Stanford, CA, USA
- Wu-Tsai Neuroscience Institute, Stanford University, 290 Jane Stanford Way, Stanford, CA, USA
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10
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Abstract
Vision and learning have long been considered to be two areas of research linked only distantly. However, recent developments in vision research have changed the conceptual definition of vision from a signal-evaluating process to a goal-oriented interpreting process, and this shift binds learning, together with the resulting internal representations, intimately to vision. In this review, we consider various types of learning (perceptual, statistical, and rule/abstract) associated with vision in the past decades and argue that they represent differently specialized versions of the fundamental learning process, which must be captured in its entirety when applied to complex visual processes. We show why the generalized version of statistical learning can provide the appropriate setup for such a unified treatment of learning in vision, what computational framework best accommodates this kind of statistical learning, and what plausible neural scheme could feasibly implement this framework. Finally, we list the challenges that the field of statistical learning faces in fulfilling the promise of being the right vehicle for advancing our understanding of vision in its entirety. Expected final online publication date for the Annual Review of Vision Science, Volume 8 is September 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- József Fiser
- Department of Cognitive Science, Center for Cognitive Computation, Central European University, Vienna 1100, Austria;
| | - Gábor Lengyel
- Department of Brain and Cognitive Sciences, University of Rochester, Rochester, New York 14627, USA
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11
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Jin L, Behabadi BF, Jadi MP, Ramachandra CA, Mel BW. Classical-Contextual Interactions in V1 May Rely on Dendritic Computations. Neuroscience 2022; 489:234-250. [PMID: 35272004 PMCID: PMC9049952 DOI: 10.1016/j.neuroscience.2022.02.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 02/14/2022] [Accepted: 02/27/2022] [Indexed: 12/20/2022]
Abstract
A signature feature of the neocortex is the dense network of horizontal connections (HCs) through which pyramidal neurons (PNs) exchange "contextual" information. In primary visual cortex (V1), HCs are thought to facilitate boundary detection, a crucial operation for object recognition, but how HCs modulate PN responses to boundary cues within their classical receptive fields (CRF) remains unknown. We began by "asking" natural images, through a structured data collection and ground truth labeling process, what function a V1 cell should use to compute boundary probability from aligned edge cues within and outside its CRF. The "answer" was an asymmetric 2-D sigmoidal function, whose nonlinear form provides the first normative account for the "multiplicative" center-flanker interactions previously reported in V1 neurons (Kapadia et al., 1995, 2000; Polat et al., 1998). Using a detailed compartmental model, we then show that this boundary-detecting classical-contextual interaction function can be computed by NMDAR-dependent spatial synaptic interactions within PN dendrites - the site where classical and contextual inputs first converge in the cortex. In additional simulations, we show that local interneuron circuitry activated by HCs can powerfully leverage the nonlinear spatial computing capabilities of PN dendrites, providing the cortex with a highly flexible substrate for integration of classical and contextual information.
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Affiliation(s)
- Lei Jin
- USC Neuroscience Graduate Program, United States
| | | | | | | | - Bartlett W Mel
- USC Neuroscience Graduate Program, United States; Department of Biomedical Engineering, University of Southern California, United States.
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12
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Adaptive erasure of spurious sequences in sensory cortical circuits. Neuron 2022; 110:1857-1868.e5. [PMID: 35358415 PMCID: PMC9616807 DOI: 10.1016/j.neuron.2022.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 11/12/2021] [Accepted: 03/07/2022] [Indexed: 12/02/2022]
Abstract
Sequential activity reflecting previously experienced temporal sequences is considered a hallmark of learning across cortical areas. However, it is unknown how cortical circuits avoid the converse problem: producing spurious sequences that are not reflecting sequences in their inputs. We develop methods to quantify and study sequentiality in neural responses. We show that recurrent circuit responses generally include spurious sequences, which are specifically prevented in circuits that obey two widely known features of cortical microcircuit organization: Dale’s law and Hebbian connectivity. In particular, spike-timing-dependent plasticity in excitation-inhibition networks leads to an adaptive erasure of spurious sequences. We tested our theory in multielectrode recordings from the visual cortex of awake ferrets. Although responses to natural stimuli were largely non-sequential, responses to artificial stimuli initially included spurious sequences, which diminished over extended exposure. These results reveal an unexpected role for Hebbian experience-dependent plasticity and Dale’s law in sensory cortical circuits. Recurrent circuits generate spurious sequences without sequential inputs A principled measure of total sequentiality in population responses is developed Theory predicts that Hebbian plasticity should abolish spurious sequences Spurious sequences in the visual cortex diminish with experience
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13
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Chen S, Weidner R, Zeng H, Fink GR, Müller HJ, Conci M. Feedback from lateral occipital cortex to V1/V2 triggers object completion: Evidence from functional magnetic resonance imaging and dynamic causal modeling. Hum Brain Mapp 2021; 42:5581-5594. [PMID: 34418200 PMCID: PMC8559483 DOI: 10.1002/hbm.25637] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Revised: 06/24/2021] [Accepted: 08/06/2021] [Indexed: 01/31/2023] Open
Abstract
Illusory figures demonstrate the visual system's ability to integrate disparate parts into coherent wholes. We probed this object integration process by either presenting an integrated diamond shape or a comparable ungrouped configuration that did not render a complete object. Two tasks were used that either required localization of a target dot (relative to the presented configuration) or discrimination of the dot's luminance. The results showed that only when the configuration was task relevant (in the localization task), performance benefited from the presentation of an integrated object. Concurrent functional magnetic resonance imaging was performed and analyzed using dynamic causal modeling to investigate the (causal) relationship between regions that are associated with illusory figure completion. We found object‐specific feedback connections between the lateral occipital cortex (LOC) and early visual cortex (V1/V2). These modulatory connections persisted across task demands and hemispheres. Our results thus provide direct evidence that interactions between mid‐level and early visual processing regions engage in illusory figure perception. These data suggest that LOC first integrates inputs from multiple neurons in lower‐level cortices, generating a global shape representation while more fine‐graded object details are then determined via feedback to early visual areas, independently of the current task demands.
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Affiliation(s)
- Siyi Chen
- Department of Psychology, Ludwig-Maximilians-Universität München, München, Germany
| | - Ralph Weidner
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Center Jülich, Jülich, Germany
| | - Hang Zeng
- Center for Educational Science and Technology, Beijing Normal University at Zhuhai, Zhuhai, China
| | - Gereon R Fink
- Cognitive Neuroscience, Institute of Neuroscience and Medicine (INM-3), Research Center Jülich, Jülich, Germany.,Department of Neurology, University Hospital Cologne, Cologne University, Cologne, Germany
| | - Hermann J Müller
- Department of Psychology, Ludwig-Maximilians-Universität München, München, Germany
| | - Markus Conci
- Department of Psychology, Ludwig-Maximilians-Universität München, München, Germany
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14
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Pang Z, O'May CB, Choksi B, VanRullen R. Predictive coding feedback results in perceived illusory contours in a recurrent neural network. Neural Netw 2021; 144:164-175. [PMID: 34500255 DOI: 10.1016/j.neunet.2021.08.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 10/20/2022]
Abstract
Modern feedforward convolutional neural networks (CNNs) can now solve some computer vision tasks at super-human levels. However, these networks only roughly mimic human visual perception. One difference from human vision is that they do not appear to perceive illusory contours (e.g. Kanizsa squares) in the same way humans do. Physiological evidence from visual cortex suggests that the perception of illusory contours could involve feedback connections. Would recurrent feedback neural networks perceive illusory contours like humans? In this work we equip a deep feedforward convolutional network with brain-inspired recurrent dynamics. The network was first pretrained with an unsupervised reconstruction objective on a natural image dataset, to expose it to natural object contour statistics. Then, a classification decision head was added and the model was finetuned on a form discrimination task: squares vs. randomly oriented inducer shapes (no illusory contour). Finally, the model was tested with the unfamiliar "illusory contour" configuration: inducer shapes oriented to form an illusory square. Compared with feedforward baselines, the iterative "predictive coding" feedback resulted in more illusory contours being classified as physical squares. The perception of the illusory contour was measurable in the luminance profile of the image reconstructions produced by the model, demonstrating that the model really "sees" the illusion. Ablation studies revealed that natural image pretraining and feedback error correction are both critical to the perception of the illusion. Finally we validated our conclusions in a deeper network (VGG): adding the same predictive coding feedback dynamics again leads to the perception of illusory contours.
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Affiliation(s)
| | | | | | - Rufin VanRullen
- CerCO, CNRS UMR5549, Toulouse, France; ANITI, Toulouse, France.
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15
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Falandays JB, Nguyen B, Spivey MJ. Is prediction nothing more than multi-scale pattern completion of the future? Brain Res 2021; 1768:147578. [PMID: 34284021 DOI: 10.1016/j.brainres.2021.147578] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 05/28/2021] [Accepted: 06/29/2021] [Indexed: 11/18/2022]
Abstract
While the notion of the brain as a prediction machine has been extremely influential and productive in cognitive science, there are competing accounts of how best to model and understand the predictive capabilities of brains. One prominent framework is of a "Bayesian brain" that explicitly generates predictions and uses resultant errors to guide adaptation. We suggest that the prediction-generation component of this framework may involve little more than a pattern completion process. We first describe pattern completion in the domain of visual perception, highlighting its temporal extension, and show how this can entail a form of prediction in time. Next, we describe the forward momentum of entrained dynamical systems as a model for the emergence of predictive processing in non-predictive systems. Then, we apply this reasoning to the domain of language, where explicitly predictive models are perhaps most popular. Here, we demonstrate how a connectionist model, TRACE, exhibits hallmarks of predictive processing without any representations of predictions or errors. Finally, we present a novel neural network model, inspired by reservoir computing models, that is entirely unsupervised and memoryless, but nonetheless exhibits prediction-like behavior in its pursuit of homeostasis. These explorations demonstrate that brain-like systems can get prediction "for free," without the need to posit formal logical representations with Bayesian probabilities or an inference machine that holds them in working memory.
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Affiliation(s)
- J Benjamin Falandays
- Department of Cognitive and Information Sciences, University of California, Merced, United States
| | - Benjamin Nguyen
- Department of Cognitive and Information Sciences, University of California, Merced, United States
| | - Michael J Spivey
- Department of Cognitive and Information Sciences, University of California, Merced, United States.
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16
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Lõoke M, Marinelli L, Guérineau C, Agrillo C, Mongillo P. Dogs (Canis lupus familiaris) are susceptible to the Kanizsa's triangle illusion. Anim Cogn 2021; 25:43-51. [PMID: 34269930 PMCID: PMC8904331 DOI: 10.1007/s10071-021-01533-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/02/2021] [Accepted: 07/09/2021] [Indexed: 11/28/2022]
Abstract
The ability to complete partially missing contours is widespread across the animal kingdom, but whether this extends to dogs is still unknown. To address this gap in knowledge, we assessed dogs' susceptibility to one of the most common contour illusions, the Kanizsa's triangle. Six dogs were trained to discriminate a triangle from other geometrical figures using a two-alternative conditioned discrimination task. Once the learning criterion was reached, dogs were presented with the Kanizsa's triangle and a control stimulus, where inducers were rotated around their centre, so as to disrupt what would be perceived as a triangle by a human observer. As a group, dogs chose the illusory triangle significantly more often than control stimuli. At the individual level, susceptibility to the illusion was shown by five out of six dogs. This is the first study where dogs as a group show susceptibility to a visual illusion in the same manner as humans. Moreover, the analyses revealed a negative effect of age on susceptibility, an effect that was also found in humans. Altogether, this suggests that the underling perceptual mechanisms are similar between dogs and humans, and in sharp contrast with other categories of visual illusions to which the susceptibility of dogs has been previously assessed.
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Affiliation(s)
- Miina Lõoke
- Laboratory of Applied Ethology, Department of Comparative Biomedicine and Food Science, University of Padua, Piazzetta del Donatore, 4, 35020, Legnaro, Italy
| | - Lieta Marinelli
- Laboratory of Applied Ethology, Department of Comparative Biomedicine and Food Science, University of Padua, Piazzetta del Donatore, 4, 35020, Legnaro, Italy.
| | - Cécile Guérineau
- Laboratory of Applied Ethology, Department of Comparative Biomedicine and Food Science, University of Padua, Piazzetta del Donatore, 4, 35020, Legnaro, Italy
| | - Christian Agrillo
- Department of General Psychology, University of Padua, 35131, Padua, Italy.,Padua Neuroscience Center, University of Padua, 35131, Padua, Italy
| | - Paolo Mongillo
- Laboratory of Applied Ethology, Department of Comparative Biomedicine and Food Science, University of Padua, Piazzetta del Donatore, 4, 35020, Legnaro, Italy
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17
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Yan C, Pérez-Bellido A, de Lange FP. Amodal completion instead of predictive coding can explain activity suppression of early visual cortex during illusory shape perception. J Vis 2021; 21:13. [PMID: 33988675 PMCID: PMC8131992 DOI: 10.1167/jov.21.5.13] [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: 11/25/2022] Open
Abstract
A set of recent neuroimaging studies observed that the perception of an illusory shape can elicit both positive and negative feedback modulations in different parts of the early visual cortex. When three Pac-Men shapes were aligned in such a way that they created an illusory triangle (i.e., the Kanizsa illusion), neural activity in early visual cortex was enhanced in those neurons that had receptive fields that overlapped with the illusory shape but suppressed in neurons whose receptive field overlapped with the Pac-Men inducers. These results were interpreted as congruent with the predictive coding framework, in which neurons in early visual cortex enhance or suppress their activity depending on whether the top-down predictions match the bottom-up sensory inputs. However, there are several plausible alternative explanations for the activity modulations. Here we tested a recent proposal (Moors, 2015) that the activity suppression in early visual cortex during illusory shape perception reflects neural adaptation to perceptually stable input. Namely, the inducers appear perceptually stable during the illusory shape condition (discs on which a triangle is superimposed), but not during the control condition (discs that change into Pac-Men). We examined this hypothesis by manipulating the perceptual stability of inducers. When the inducers could be perceptually interpreted as persistent circles, we replicated the up- and downregulation pattern shown in previous studies. However, when the inducers could not be perceived as persistent circles, we still observed enhanced activity in neurons representing the illusory shape but the suppression of activity in neurons representing the inducers was absent. Thus our results support the hypothesis that the activity suppression in neurons representing the inducers during the Kanizsa illusion is better explained by neural adaptation to perceptually stable input than by reduced prediction error.
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Affiliation(s)
- Chuyao Yan
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands.,
| | - Alexis Pérez-Bellido
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands.,Department of Cognition, Development and Educational Psychology, University of Barcelona, Barcelona, Spain.,Institute of Neurosciences, University of Barcelona, Barcelona, Spain.,
| | - Floris P de Lange
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands.,
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18
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Grossberg S. A Canonical Laminar Neocortical Circuit Whose Bottom-Up, Horizontal, and Top-Down Pathways Control Attention, Learning, and Prediction. Front Syst Neurosci 2021; 15:650263. [PMID: 33967708 PMCID: PMC8102731 DOI: 10.3389/fnsys.2021.650263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/29/2021] [Indexed: 11/27/2022] Open
Abstract
All perceptual and cognitive circuits in the human cerebral cortex are organized into layers. Specializations of a canonical laminar network of bottom-up, horizontal, and top-down pathways carry out multiple kinds of biological intelligence across different neocortical areas. This article describes what this canonical network is and notes that it can support processes as different as 3D vision and figure-ground perception; attentive category learning and decision-making; speech perception; and cognitive working memory (WM), planning, and prediction. These processes take place within and between multiple parallel cortical streams that obey computationally complementary laws. The interstream interactions that are needed to overcome these complementary deficiencies mix cell properties so thoroughly that some authors have noted the difficulty of determining what exactly constitutes a cortical stream and the differences between streams. The models summarized herein explain how these complementary properties arise, and how their interstream interactions overcome their computational deficiencies to support effective goal-oriented behaviors.
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Affiliation(s)
- Stephen Grossberg
- Graduate Program in Cognitive and Neural Systems, Departments of Mathematics and Statistics, Psychological and Brain Sciences, and Biomedical Engineering, Center for Adaptive Systems, Boston University, Boston, MA, United States
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19
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Keane BP, Barch DM, Mill RD, Silverstein SM, Krekelberg B, Cole MW. Brain network mechanisms of visual shape completion. Neuroimage 2021; 236:118069. [PMID: 33878383 PMCID: PMC8456451 DOI: 10.1016/j.neuroimage.2021.118069] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 11/06/2022] Open
Abstract
Visual shape completion recovers object shape, size, and number from spatially segregated edges. Despite being extensively investigated, the process’s underlying brain regions, networks, and functional connections are still not well understood. To shed light on the topic, we scanned (fMRI) healthy adults during rest and during a task in which they discriminated pac-man configurations that formed or failed to form completed shapes (illusory and fragmented condition, respectively). Task activation differences (illusory-fragmented), resting-state functional connectivity, and multivariate patterns were identified on the cortical surface using 360 predefined parcels and 12 functional networks composed of such parcels. Brain activity flow mapping (ActFlow) was used to evaluate the likely involvement of resting-state connections for shape completion. We identified 36 differentially-active parcels including a posterior temporal region, PH, whose activity was consistent across 95% of observers. Significant task regions primarily occupied the secondary visual network but also incorporated the frontoparietal dorsal attention, default mode, and cingulo-opercular networks. Each parcel’s task activation difference could be modeled via its resting-state connections with the remaining parcels (r=.62, p<10−9), suggesting that such connections undergird shape completion. Functional connections from the dorsal attention network were key in modelling task activation differences in the secondary visual network. Dorsal attention and frontoparietal connections could also model activations in the remaining networks. Taken together, these results suggest that shape completion relies upon a sparsely distributed but densely interconnected network coalition that is centered in the secondary visual network, coordinated by the dorsal attention network, and inclusive of at least three other networks.
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Affiliation(s)
- Brian P Keane
- University Behavioral Health Care, Department of Psychiatry, and Center for Cognitive Science, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Departments of Psychiatry and Neuroscience, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, USA.
| | - Deanna M Barch
- Departments of Psychological & Brain Sciences, Psychiatry, and Radiology, Washington University in St. Louis, One Brookings Drive, St. Louis, MO 63130, USA
| | - Ravi D Mill
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, 197 University Ave 07102, USA
| | - Steven M Silverstein
- University Behavioral Health Care, Department of Psychiatry, and Center for Cognitive Science, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA; Departments of Psychiatry and Neuroscience, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY 14642, USA; Department of Ophthalmology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, USA
| | - Bart Krekelberg
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, 197 University Ave 07102, USA
| | - Michael W Cole
- Center for Molecular and Behavioral Neuroscience, Rutgers, The State University of New Jersey, 197 University Ave 07102, USA
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20
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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: 4] [Impact Index Per Article: 1.3] [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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21
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Han C, Wang T, Wu Y, Li Y, Yang Y, Li L, Wang Y, Xing D. The Generation and Modulation of Distinct Gamma Oscillations with Local, Horizontal, and Feedback Connections in the Primary Visual Cortex: A Model Study on Large-Scale Networks. Neural Plast 2021; 2021:8874516. [PMID: 33531893 PMCID: PMC7834828 DOI: 10.1155/2021/8874516] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 10/25/2020] [Accepted: 11/12/2020] [Indexed: 11/23/2022] Open
Abstract
Gamma oscillation (GAMMA) in the local field potential (LFP) is a synchronized activity commonly found in many brain regions, and it has been thought as a functional signature of network connectivity in the brain, which plays important roles in information processing. Studies have shown that the response property of GAMMA is related to neural interaction through local recurrent connections (RC), feed-forward (FF), and feedback (FB) connections. However, the relationship between GAMMA and long-range horizontal connections (HC) in the brain remains unclear. Here, we aimed to understand this question in a large-scale network model for the primary visual cortex (V1). We created a computational model composed of multiple excitatory and inhibitory units with biologically plausible connectivity patterns for RC, FF, FB, and HC in V1; then, we quantitated GAMMA in network models at different strength levels of HC and other connection types. Surprisingly, we found that HC and FB, the two types of large-scale connections, play very different roles in generating and modulating GAMMA. While both FB and HC modulate a fast gamma oscillation (around 50-60 Hz) generated by FF and RC, HC generates a new GAMMA oscillating around 30 Hz, whose power and peak frequency can also be modulated by FB. Furthermore, response properties of the two GAMMAs in a network with both HC and FB are different in a way that is highly consistent with a recent experimental finding for distinct GAMMAs in macaque V1. The results suggest that distinct GAMMAs are signatures for neural connections in different spatial scales and they might be related to different functions for information integration. Our study, for the first time, pinpoints the underlying circuits for distinct GAMMAs in a mechanistic model for macaque V1, which might provide a new framework to study multiple gamma oscillations in other cortical regions.
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Affiliation(s)
- Chuanliang Han
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Tian Wang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Yujie Wu
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Yang Li
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Yi Yang
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
| | - Liang Li
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Yizheng Wang
- Beijing Institute of Basic Medical Sciences, Beijing 100850, China
| | - Dajun Xing
- State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing 100875, China
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22
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Marquardt I, De Weerd P, Schneider M, Gulban OF, Ivanov D, Wang Y, Uludağ K. Feedback contribution to surface motion perception in the human early visual cortex. eLife 2020; 9:e50933. [PMID: 32496189 PMCID: PMC7314553 DOI: 10.7554/elife.50933] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 06/03/2020] [Indexed: 01/03/2023] Open
Abstract
Human visual surface perception has neural correlates in early visual cortex, but the role of feedback during surface segmentation in human early visual cortex remains unknown. Feedback projections preferentially enter superficial and deep anatomical layers, which provides a hypothesis for the cortical depth distribution of fMRI activity related to feedback. Using ultra-high field fMRI, we report a depth distribution of activation in line with feedback during the (illusory) perception of surface motion. Our results fit with a signal re-entering in superficial depths of V1, followed by a feedforward sweep of the re-entered information through V2 and V3. The magnitude and sign of the BOLD response strongly depended on the presence of texture in the background, and was additionally modulated by the presence of illusory motion perception compatible with feedback. In summary, the present study demonstrates the potential of depth-resolved fMRI in tackling biomechanical questions on perception.
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Affiliation(s)
- Ingo Marquardt
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
| | - Peter De Weerd
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
- Maastricht Center of Systems Biology (MACSBIO), Faculty of Science & Engineering, Maastricht UniversityMaastrichtNetherlands
| | - Marian Schneider
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
| | - Omer Faruk Gulban
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
| | - Dimo Ivanov
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
| | - Yawen Wang
- Department of Cognitive Neuroscience, Maastricht Brain Imaging Centre (MBIC) Faculty of Psychology and Neuroscience, Maastricht UniversityMaastrichtNetherlands
| | - Kâmil Uludağ
- Center for Neuroscience Imaging Research, Institute for Basic Science and Department of Biomedical Engineering, N Center, Sungkyunkwan UniversityJangan-guRepublic of Korea
- Techna Institute and Koerner Scientist in MR Imaging, University Health NetworkTorontoCanada
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23
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Keller AJ, Roth MM, Scanziani M. Feedback generates a second receptive field in neurons of the visual cortex. Nature 2020; 582:545-549. [PMID: 32499655 PMCID: PMC7790439 DOI: 10.1038/s41586-020-2319-4] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 03/10/2020] [Indexed: 01/29/2023]
Abstract
Animals sense the environment through pathways that link sensory organs to the brain. In the visual system, these feedforward pathways define the classical feedforward receptive field (ffRF), the area in space in which visual stimuli excite a neuron1. The visual system also uses visual context-the visual scene surrounding a stimulus-to predict the content of the stimulus2, and accordingly, neurons have been identified that are excited by stimuli outside their ffRF3-8. However, the mechanisms that generate excitation to stimuli outside the ffRF are unclear. Here we show that feedback projections onto excitatory neurons in the mouse primary visual cortex generate a second receptive field that is driven by stimuli outside the ffRF. The stimulation of this feedback receptive field (fbRF) elicits responses that are slower and are delayed in comparison with those resulting from the stimulation of the ffRF. These responses are preferentially reduced by anaesthesia and by silencing higher visual areas. Feedback inputs from higher visual areas have scattered receptive fields relative to their putative targets in the primary visual cortex, which enables the generation of the fbRF. Neurons with fbRFs are located in cortical layers that receive strong feedback projections and are absent in the main input layer, which is consistent with a laminar processing hierarchy. The observation that large, uniform stimuli-which cover both the fbRF and the ffRF-suppress these responses indicates that the fbRF and the ffRF are mutually antagonistic. Whereas somatostatin-expressing inhibitory neurons are driven by these large stimuli, inhibitory neurons that express parvalbumin and vasoactive intestinal peptide have mutually antagonistic fbRF and ffRF, similar to excitatory neurons. Feedback projections may therefore enable neurons to use context to estimate information that is missing from the ffRF and to report differences in stimulus features across visual space, regardless of whether excitation occurs inside or outside the ffRF. By complementing the ffRF, the fbRF that we identify here could contribute to predictive processing.
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Affiliation(s)
- Andreas J Keller
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA, USA.
| | - Morgane M Roth
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA, USA
| | - Massimo Scanziani
- Department of Physiology, University of California San Francisco, San Francisco, CA, USA.
- Howard Hughes Medical Institute, University of California San Francisco, San Francisco, CA, USA.
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24
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Everything is subjective under water surface, too: visual illusions in fish. Anim Cogn 2020; 23:251-264. [PMID: 31897795 DOI: 10.1007/s10071-019-01341-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 12/09/2019] [Accepted: 12/13/2019] [Indexed: 12/20/2022]
Abstract
The study of visual illusions has captured the attention of comparative psychologists since the last century, given the unquestionable advantage of investigating complex perceptual mechanisms with relatively simple visual patterns. To date, the observation of animal behavior in the presence of visual illusions has been largely confined to mammal and bird studies. Recently, there has been increasing interest in investigating fish, too. The attention has been particularly focused on guppies, redtail splitfin and bamboo sharks. Overall, the tested species were shown to experience a human-like perception of different illusory phenomena involving size, number, motion, brightness estimation and illusory contours. However, in some cases, no illusory effects, or evidence for a reverse illusion, were also reported. Here, we review the current state of the art in this field. We conclude that a wider investigation of visual illusions in fish is fundamental to form a broader comprehension of perceptual systems of vertebrates. Furthermore, we believe that this type of investigation could help us to address general important issues in perceptual studies, such as the role of ecology in shaping perceptual systems, the existence of interindividual variability in the visual perception of nonhuman species and the role of cortical activity in the emergence of visual illusions.
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25
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Top-Down Feedback Controls the Cortical Representation of Illusory Contours in Mouse Primary Visual Cortex. J Neurosci 2019; 40:648-660. [PMID: 31792152 DOI: 10.1523/jneurosci.1998-19.2019] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/29/2019] [Accepted: 11/15/2019] [Indexed: 01/01/2023] Open
Abstract
Visual systems have evolved to recognize and extract features from complex scenes using limited sensory information. Contour perception is essential to this process and can occur despite breaks in the continuity of neighboring features. Such robustness of the animal visual system to degraded or occluded shapes may also give rise to an interesting phenomenon of optical illusions. These illusions provide a great opportunity to decipher neural computations underlying contour integration and object detection. Kanizsa illusory contours have been shown to evoke responses in the early visual cortex despite the lack of direct receptive field activation. Recurrent processing between visual areas has been proposed to be involved in this process. However, it is unclear whether higher visual areas directly contribute to the generation of illusory responses in the early visual cortex. Using behavior, in vivo electrophysiology, and optogenetics, we first show that the primary visual cortex (V1) of male mice responds to Kanizsa illusory contours. Responses to Kanizsa illusions emerge later than the responses to the contrast-defined real contours in V1. Second, we demonstrate that illusory responses are orientation-selective. Finally, we show that top-down feedback controls the neural correlates of illusory contour perception in V1. Our results suggest that higher-order visual areas may fill in the missing information in the early visual cortex necessary for illusory contour perception.SIGNIFICANCE STATEMENT Perception of the Kanizsa illusory contours is impaired in neurodevelopmental disorders such as schizophrenia, autism, and Williams syndrome. However, the mechanism of the illusory contour perception is poorly understood. Here we describe the behavioral and neural correlates of Kanizsa illusory contours perception in mice, a genetically tractable model system. We show that top-down feedback controls the neural responses to Kanizsa illusion in V1. To our knowledge, this is the first description of the neural correlates of the Kanizsa illusion in mice and the first causal demonstration of their regulation by top-down feedback.
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26
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Wittenhagen L, Mattingley JB. Attentional modulation of neural responses to illusory shapes: Evidence from steady-state and evoked visual potentials. Neuropsychologia 2019; 125:70-80. [DOI: 10.1016/j.neuropsychologia.2019.01.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 11/20/2018] [Accepted: 01/29/2019] [Indexed: 10/27/2022]
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27
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Going with the Flow: The Neural Mechanisms Underlying Illusions of Complex-Flow Motion. J Neurosci 2019; 39:2664-2685. [PMID: 30777886 DOI: 10.1523/jneurosci.2112-18.2019] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 11/21/2022] Open
Abstract
Studying the mismatch between perception and reality helps us better understand the constructive nature of the visual brain. The Pinna-Brelstaff motion illusion is a compelling example illustrating how a complex moving pattern can generate an illusory motion perception. When an observer moves toward (expansion) or away (contraction) from the Pinna-Brelstaff figure, the figure appears to rotate. The neural mechanisms underlying the illusory complex-flow motion of rotation, expansion, and contraction remain unknown. We studied this question at both perceptual and neuronal levels in behaving male macaques by using carefully parametrized Pinna-Brelstaff figures that induce the above motion illusions. We first demonstrate that macaques perceive illusory motion in a manner similar to that of human observers. Neurophysiological recordings were subsequently performed in the middle temporal area (MT) and the dorsal portion of the medial superior temporal area (MSTd). We find that subgroups of MSTd neurons encoding a particular global pattern of real complex-flow motion (rotation, expansion, contraction) also represent illusory motion patterns of the same class. They require an extra 15 ms to reliably discriminate the illusion. In contrast, MT neurons encode both real and illusory local motions with similar temporal delays. These findings reveal that illusory complex-flow motion is first represented in MSTd by the same neurons that normally encode real complex-flow motion. However, the extraction of global illusory motion in MSTd from other classes of real complex-flow motion requires extra processing time. Our study illustrates a cascaded integration mechanism from MT to MSTd underlying the transformation from external physical to internal nonveridical flow-motion perception.SIGNIFICANCE STATEMENT The neural basis of the transformation from objective reality to illusory percepts of rotation, expansion, and contraction remains unknown. We demonstrate psychophysically that macaques perceive these illusory complex-flow motions in a manner similar to that of human observers. At the neural level, we show that medial superior temporal (MSTd) neurons represent illusory flow motions as if they were real by globally integrating middle temporal area (MT) local motion signals. Furthermore, while MT neurons reliably encode real and illusory local motions with similar temporal delays, MSTd neurons take a significantly longer time to process the signals associated with illusory percepts. Our work extends previous complex-flow motion studies by providing the first detailed analysis of the neuron-specific mechanisms underlying complex forms of illusory motion integration from MT to MSTd.
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Peter A, Uran C, Klon-Lipok J, Roese R, van Stijn S, Barnes W, Dowdall JR, Singer W, Fries P, Vinck M. Surface color and predictability determine contextual modulation of V1 firing and gamma oscillations. eLife 2019; 8:42101. [PMID: 30714900 PMCID: PMC6391066 DOI: 10.7554/elife.42101] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 01/30/2019] [Indexed: 12/03/2022] Open
Abstract
The integration of direct bottom-up inputs with contextual information is a core feature of neocortical circuits. In area V1, neurons may reduce their firing rates when their receptive field input can be predicted by spatial context. Gamma-synchronized (30–80 Hz) firing may provide a complementary signal to rates, reflecting stronger synchronization between neuronal populations receiving mutually predictable inputs. We show that large uniform surfaces, which have high spatial predictability, strongly suppressed firing yet induced prominent gamma synchronization in macaque V1, particularly when they were colored. Yet, chromatic mismatches between center and surround, breaking predictability, strongly reduced gamma synchronization while increasing firing rates. Differences between responses to different colors, including strong gamma-responses to red, arose from stimulus adaptation to a full-screen background, suggesting prominent differences in adaptation between M- and L-cone signaling pathways. Thus, synchrony signaled whether RF inputs were predicted from spatial context, while firing rates increased when stimuli were unpredicted from context.
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Affiliation(s)
- Alina Peter
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,International Max Planck Research School for Neural Circuits, Frankfurt, Germany
| | - Cem Uran
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany
| | - Johanna Klon-Lipok
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,Max Planck Institute for Brain Research, Frankfurt, Germany
| | - Rasmus Roese
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany
| | - Sylvia van Stijn
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,Max Planck Institute for Brain Research, Frankfurt, Germany
| | - William Barnes
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany
| | - Jarrod R Dowdall
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany
| | - Wolf Singer
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,Frankfurt Institute for Advanced Studies, Frankfurt, Germany
| | - Pascal Fries
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Nijmegen, Netherlands
| | - Martin Vinck
- Ernst Strüngmann Institute (ESI) for Neuroscience in Cooperation with Max Planck Society, Frankfurt, Germany
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29
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Tivadar RI, Retsa C, Turoman N, Matusz PJ, Murray MM. Sounds enhance visual completion processes. Neuroimage 2018; 179:480-488. [PMID: 29959049 DOI: 10.1016/j.neuroimage.2018.06.070] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 06/13/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022] Open
Abstract
Everyday vision includes the detection of stimuli, figure-ground segregation, as well as object localization and recognition. Such processes must often surmount impoverished or noisy conditions; borders are perceived despite occlusion or absent contrast gradients. These illusory contours (ICs) are an example of so-called mid-level vision, with an event-related potential (ERP) correlate at ∼100-150 ms post-stimulus onset and originating within lateral-occipital cortices (the ICeffect). Presently, visual completion processes supporting IC perception are considered exclusively visual; any influence from other sensory modalities is currently unknown. It is now well-established that multisensory processes can influence both low-level vision (e.g. detection) as well as higher-level object recognition. By contrast, it is unknown if mid-level vision exhibits multisensory benefits and, if so, through what mechanisms. We hypothesized that sounds would impact the ICeffect. We recorded 128-channel ERPs from 17 healthy, sighted participants who viewed ICs or no-contour (NC) counterparts either in the presence or absence of task-irrelevant sounds. The ICeffect was enhanced by sounds and resulted in the recruitment of a distinct configuration of active brain areas over the 70-170 ms post-stimulus period. IC-related source-level activity within the lateral occipital cortex (LOC), inferior parietal lobe (IPL), as well as primary visual cortex (V1) were enhanced by sounds. Moreover, the activity in these regions was correlated when sounds were present, but not when absent. Results from a control experiment, which employed amodal variants of the stimuli, suggested that sounds impact the perceived brightness of the IC rather than shape formation per se. We provide the first demonstration that multisensory processes augment mid-level vision and everyday visual completion processes, and that one of the mechanisms is brightness enhancement. These results have important implications for the design of treatments and/or visual aids for low-vision patients.
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Affiliation(s)
- Ruxandra I Tivadar
- The LINE (Laboratory for Investigative Neurophysiology), Department of Radiology, University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland; Department of Ophthalmology, University of Lausanne and Fondation Asile des Aveugles, 1003, Lausanne, Switzerland
| | - Chrysa Retsa
- The LINE (Laboratory for Investigative Neurophysiology), Department of Radiology, University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland
| | - Nora Turoman
- The LINE (Laboratory for Investigative Neurophysiology), Department of Radiology, University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland
| | - Pawel J Matusz
- The LINE (Laboratory for Investigative Neurophysiology), Department of Radiology, University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland; Information Systems Institute at the University of Applied Sciences Western Switzerland (HES-SO Valais), 3960, Sierre, Switzerland
| | - Micah M Murray
- The LINE (Laboratory for Investigative Neurophysiology), Department of Radiology, University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland; Department of Ophthalmology, University of Lausanne and Fondation Asile des Aveugles, 1003, Lausanne, Switzerland; The EEG Brain Mapping Core, Center for Biomedical Imaging (CIBM), University Hospital Center and University of Lausanne, 1011, Lausanne, Switzerland; Department of Hearing and Speech Sciences, Vanderbilt University, Nashville, TN, 37203-5721, USA.
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Roth ZN, Heeger DJ, Merriam EP. Stimulus vignetting and orientation selectivity in human visual cortex. eLife 2018; 7:e37241. [PMID: 30106372 PMCID: PMC6092116 DOI: 10.7554/elife.37241] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 07/01/2018] [Indexed: 01/03/2023] Open
Abstract
Neural selectivity to orientation is one of the simplest and most thoroughly-studied cortical sensory features. Here, we show that a large body of research that purported to measure orientation tuning may have in fact been inadvertently measuring sensitivity to second-order changes in luminance, a phenomenon we term 'vignetting'. Using a computational model of neural responses in primary visual cortex (V1), we demonstrate the impact of vignetting on simulated V1 responses. We then used the model to generate a set of predictions, which we confirmed with functional MRI experiments in human observers. Our results demonstrate that stimulus vignetting can wholly determine the orientation selectivity of responses in visual cortex measured at a macroscopic scale, and suggest a reinterpretation of a well-established literature on orientation processing in visual cortex.
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Affiliation(s)
- Zvi N Roth
- Laboratory of Brain and CognitionNational Institute of Mental Health, National Institutes of HealthBethesdaUnited States
| | - David J Heeger
- Department of PsychologyNew York UniversityNew YorkUnited States
- Center for Neural ScienceNew York UniversityNew YorkUnited States
| | - Elisha P Merriam
- Laboratory of Brain and CognitionNational Institute of Mental Health, National Institutes of HealthBethesdaUnited States
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31
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Thomas RA, Metzen MG, Chacron MJ. Weakly electric fish distinguish between envelope stimuli arising from different behavioral contexts. ACTA ACUST UNITED AC 2018; 221:jeb.178244. [PMID: 29954835 DOI: 10.1242/jeb.178244] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2018] [Accepted: 06/14/2018] [Indexed: 11/20/2022]
Abstract
Understanding how sensory information is processed by the brain in order to give rise to behavior remains poorly understood in general. Here, we investigated the behavioral responses of the weakly electric fish Apteronotus albifrons to stimuli arising from different contexts, by measuring changes in the electric organ discharge (EOD) frequency. Specifically, we focused on envelopes, which can arise either because of movement (i.e. motion envelopes) or because of interactions between the electric fields of three of more fish (i.e. social envelopes). Overall, we found that the animal's EOD frequency effectively tracked the detailed time course of both motion and social envelopes. In general, behavioral sensitivity (i.e. gain) decreased while phase lag increased with increasing envelope and carrier frequency. However, changes in gain and phase lag as a function of changes in carrier frequency were more prominent for motion than for social envelopes in general. Importantly, we compared behavioral responses to motion and social envelopes with similar characteristics. Although behavioral sensitivities were similar, we observed an increased response lag for social envelopes, primarily for low carrier frequencies. Thus, our results imply that the organism can, based on behavioral responses, distinguish envelope stimuli resulting from movement from those that instead result from social interactions. We discuss the implications of our results for neural coding of envelopes and propose that behavioral responses to motion and social envelopes are mediated by different neural circuits in the brain.
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Affiliation(s)
- Rhalena A Thomas
- Department of Physiology, McGill University, Montreal, Quebec, Canada H3G 1Y6
| | - Michael G Metzen
- Department of Physiology, McGill University, Montreal, Quebec, Canada H3G 1Y6
| | - Maurice J Chacron
- Department of Physiology, McGill University, Montreal, Quebec, Canada H3G 1Y6
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32
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Brain mechanisms for perceiving illusory lines in humans. Neuroimage 2018; 181:182-189. [PMID: 30008430 DOI: 10.1016/j.neuroimage.2018.07.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 06/29/2018] [Accepted: 07/06/2018] [Indexed: 11/23/2022] Open
Abstract
Illusory contours (ICs) are perceptions of visual borders despite absent contrast gradients. The psychophysical and neurobiological mechanisms of IC processes have been studied across species and diverse brain imaging/mapping techniques. Nonetheless, debate continues regarding whether IC sensitivity results from a (presumably) feedforward process within low-level visual cortices (V1/V2) or instead are processed first within higher-order brain regions, such as lateral occipital cortices (LOC). Studies in animal models, which generally favour a feedforward mechanism within V1/V2, have typically involved stimuli inducing IC lines. By contrast, studies in humans generally favour a mechanism where IC sensitivity is mediated by LOC and have typically involved stimuli inducing IC forms or shapes. Thus, the particular stimulus features used may strongly contribute to the model of IC sensitivity supported. To address this, we recorded visual evoked potentials (VEPs) while presenting human observers with an array of 10 inducers within the central 5°, two of which could be oriented to induce an IC line on a given trial. VEPs were analysed using an electrical neuroimaging framework. Sensitivity to the presence vs. absence of centrally-presented IC lines was first apparent at ∼200 ms post-stimulus onset and was evident as topographic differences across conditions. We also localized these differences to the LOC. The timing and localization of these effects are consistent with a model of IC sensitivity commencing within higher-level visual cortices. We propose that prior observations of effects within lower-tier cortices (V1/V2) are the result of feedback from IC sensitivity that originates instead within higher-tier cortices (LOC).
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33
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Elliott SL, Shevell SK. Illusory edges comingle with real edges in the neural representation of objects. Vision Res 2018; 144:47-51. [PMID: 29454884 DOI: 10.1016/j.visres.2018.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 01/19/2018] [Accepted: 01/20/2018] [Indexed: 11/29/2022]
Abstract
The visual system must transform a point-by-point biological representation from the photoreceptors into neural representations of separate objects. Even a uniform circular patch of light that slowly modulates in luminance can be segmented into separate central and surrounding areas merely by introducing black lines to outline a central square. The black lines cause brightness induction in the center even though the light inside and outside the square is always identical, as predicted by spatial antagonism between the square central area and its surround. Importantly, illusory Kanizsa lines forming the square are as effective for this brightness induction as real black lines, suggesting a 'form-cue invariant' cortical neural representation that does not distinguish between a central region set off by real or illusory edges. An open question is whether separate subsystems generate objects defined by real versus illusory edges, each providing the same form-cue invariant neural representation of an object, or whether form-cue invariance extends to integrating component pieces that together define an object. Experiments here show object segmentation when subparts of a square are defined by a mixture of real and illusory edges. Subjects adjusted the Michelson contrast of a separate patch to match the perceived modulation depth within the central region of a circular field that slowly oscillated in luminance. A closed, four-sided figure, no matter how constructed, reduced the perceived modulation depth within the central region. This shows that both real and illusory subparts can be integrated to segment center from surround. It supports a strong version of form-cue invariance in which neural mechanisms responsible for object segmentation are impartial to the piecemeal cues that are integrated to define an object.
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Affiliation(s)
- Sarah L Elliott
- Department of Psychology, Roosevelt University, 430 S. Michigan Ave, Chicago, IL 60605, United States; Institute for Mind & Biology, University of Chicago, United States.
| | - Steven K Shevell
- Department of Psychology, The University of Chicago, 940 E. 57th St., Chicago, IL 60637, United States; Institute for Mind & Biology, University of Chicago, United States; Department of Ophthalmology & Visual Science, University of Chicago, United States
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34
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Contour interpolation: A case study in Modularity of Mind. Cognition 2018; 174:1-18. [PMID: 29407601 DOI: 10.1016/j.cognition.2018.01.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 01/17/2018] [Accepted: 01/18/2018] [Indexed: 01/29/2023]
Abstract
In his monograph Modularity of Mind (1983), philosopher Jerry Fodor argued that mental architecture can be partly decomposed into computational organs termed modules, which were characterized as having nine co-occurring features such as automaticity, domain specificity, and informational encapsulation. Do modules exist? Debates thus far have been framed very generally with few, if any, detailed case studies. The topic is important because it has direct implications on current debates in cognitive science and because it potentially provides a viable framework from which to further understand and make hypotheses about the mind's structure and function. Here, the case is made for the modularity of contour interpolation, which is a perceptual process that represents non-visible edges on the basis of how surrounding visible edges are spatiotemporally configured. There is substantial evidence that interpolation is domain specific, mandatory, fast, and developmentally well-sequenced; that it produces representationally impoverished outputs; that it relies upon a relatively fixed neural architecture that can be selectively impaired; that it is encapsulated from belief and expectation; and that its inner workings cannot be fathomed through conscious introspection. Upon differentiating contour interpolation from a higher-order contour representational ability ("contour abstraction") and upon accommodating seemingly inconsistent experimental results, it is argued that interpolation is modular to the extent that the initiating conditions for interpolation are strong. As interpolated contours become more salient, the modularity features emerge. The empirical data, taken as a whole, show that at least certain parts of the mind are modularly organized.
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35
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Spatially selective responses to Kanizsa and occlusion stimuli in human visual cortex. Sci Rep 2018; 8:611. [PMID: 29330457 PMCID: PMC5766606 DOI: 10.1038/s41598-017-19121-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Accepted: 12/16/2017] [Indexed: 11/12/2022] Open
Abstract
Early visual cortex responds to illusory contours in which abutting lines or collinear edges imply the presence of an occluding surface, as well as to occluded parts of an object. Here we used functional magnetic resonance imaging (fMRI) and population receptive field (pRF) analysis to map retinotopic responses in early visual cortex using bar stimuli defined by illusory contours, occluded parts of a bar, or subtle luminance contrast. All conditions produced retinotopic responses in early visual field maps even though signal-to-noise ratios were very low. We found that signal-to-noise ratios and coherence with independent high-contrast mapping data increased from V1 to V2 to V3. Moreover, we found no differences of signal-to-noise ratios or pRF sizes between the low-contrast luminance and illusion conditions. We propose that all three conditions mapped spatial attention to the bar location rather than activations specifically related to illusory contours or occlusion.
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36
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Leinweber M, Ward DR, Sobczak JM, Attinger A, Keller GB. A Sensorimotor Circuit in Mouse Cortex for Visual Flow Predictions. Neuron 2017; 95:1420-1432.e5. [PMID: 28910624 DOI: 10.1016/j.neuron.2017.08.036] [Citation(s) in RCA: 165] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 06/30/2017] [Accepted: 08/24/2017] [Indexed: 11/26/2022]
Abstract
The cortex is organized as a hierarchical processing structure. Feedback from higher levels of the hierarchy, known as top-down signals, have been shown to be involved in attentional and contextual modulation of sensory responses. Here we argue that top-down input to the primary visual cortex (V1) from A24b and the adjacent secondary motor cortex (M2) signals a prediction of visual flow based on motor output. A24b/M2 sends a dense and topographically organized projection to V1 that targets most neurons in layer 2/3. By imaging the activity of A24b/M2 axons in V1 of mice learning to navigate a 2D virtual environment, we found that their activity was strongly correlated with locomotion and resulting visual flow feedback in an experience-dependent manner. When mice were trained to navigate a left-right inverted virtual environment, correlations of neural activity with behavior reversed to match visual flow. These findings are consistent with a predictive coding interpretation of visual processing.
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Affiliation(s)
- Marcus Leinweber
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Daniel R Ward
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Jan M Sobczak
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Alexander Attinger
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Georg B Keller
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland.
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Aitchison L, Lengyel M. With or without you: predictive coding and Bayesian inference in the brain. Curr Opin Neurobiol 2017; 46:219-227. [PMID: 28942084 DOI: 10.1016/j.conb.2017.08.010] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Accepted: 08/23/2017] [Indexed: 12/24/2022]
Abstract
Two theoretical ideas have emerged recently with the ambition to provide a unifying functional explanation of neural population coding and dynamics: predictive coding and Bayesian inference. Here, we describe the two theories and their combination into a single framework: Bayesian predictive coding. We clarify how the two theories can be distinguished, despite sharing core computational concepts and addressing an overlapping set of empirical phenomena. We argue that predictive coding is an algorithmic/representational motif that can serve several different computational goals of which Bayesian inference is but one. Conversely, while Bayesian inference can utilize predictive coding, it can also be realized by a variety of other representations. We critically evaluate the experimental evidence supporting Bayesian predictive coding and discuss how to test it more directly.
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Affiliation(s)
- Laurence Aitchison
- Computational & Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom
| | - Máté Lengyel
- Computational & Biological Learning Lab, Department of Engineering, University of Cambridge, Cambridge, United Kingdom; Department of Cognitive Science, Central European University, Budapest, Hungary.
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Consistency of Border-Ownership Cells across Artificial Stimuli, Natural Stimuli, and Stimuli with Ambiguous Contours. J Neurosci 2017; 36:11338-11349. [PMID: 27807174 DOI: 10.1523/jneurosci.1857-16.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/10/2016] [Indexed: 11/21/2022] Open
Abstract
Segmentation and recognition of objects in a visual scene are two problems that are hard to solve separately from each other. When segmenting an ambiguous scene, it is helpful to already know the present objects and their shapes. However, for recognizing an object in clutter, one would like to consider its isolated segment alone to avoid confounds from features of other objects. Border-ownership cells (Zhou et al., 2000) appear to play an important role in segmentation, as they signal the side-of-figure of artificial stimuli. The present work explores the role of border-ownership cells in dorsal macaque visual areas V2 and V3 in the segmentation of natural object stimuli and locally ambiguous stimuli. We report two major results. First, compared with previous estimates, we found a smaller percentage of cells that were consistent across artificial stimuli used previously. Second, we found that the average response of those neurons that did respond consistently to the side-of-figure of artificial stimuli also consistently signaled, as a population, the side-of-figure for borders of single faces, occluding faces and, with higher latencies, even stimuli with illusory contours, such as Mooney faces and natural faces completely missing local edge information. In contrast, the local edge or the outlines of the face alone could not always evoke a significant border-ownership signal. Our results underscore that border ownership is coded by a population of cells, and indicate that these cells integrate a variety of cues, including low-level features and global object context, to compute the segmentation of the scene. SIGNIFICANCE STATEMENT To distinguish different objects in a natural scene, the brain must segment the image into regions corresponding to objects. The so-called "border-ownership" cells appear to be dedicated to this task, as they signal for a given edge on which side the object is that owns it. Here, we report that individual border-ownership cells are unreliable when tested across a battery of artificial stimuli used previously but can signal border-ownership consistently as a population. We show that these border-ownership population signals are also suited for signaling border-ownership for natural objects and at longer latency, even for stimuli without local edge information. Our results suggest that border-ownership cells integrate both local, low-level and global, high-level cues to segment the scene.
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Jimenez M, Montoro PR, Luna D. Global shape integration and illusory form perception in the absence of awareness. Conscious Cogn 2017; 53:31-46. [PMID: 28618282 DOI: 10.1016/j.concog.2017.05.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Revised: 05/10/2017] [Accepted: 05/22/2017] [Indexed: 11/26/2022]
Abstract
Previous research on perceptual organization operations still provides contradictory evidence on whether the integration of sparse local elements into coherently unified shapes and the construction of the illusory form are accomplished without the need of awareness. In the present study, three experiments were conducted in which participants were presented with masked (Experiment 1, SOA=27ms; Experiment 2; SOA=53ms) and unmasked (Experiment 3) primes consisting of geometric shapes (a square or a diamond) that could be congruent or incongruent with subsequent probe stimuli (square vs. diamond). Furthermore, the primes were divided into: a grouping condition (where local elements may group together into global shapes), an illusory condition (where the arrangement of local elements produced illusory shapes) and a hybrid condition (where both operations were presented simultaneously). While no priming effects were found for the shortest SOA (27ms), both grouping and illusory primes produced significant priming effects in the longer SOA (53ms). On the other hand, results in Experiment 3 (unmasked) showed strong priming effects for the grouping of the inducers in both the grouping and the hybrid conditions, and also a significant but weaker priming effect for the illusory condition. Overall, our results support the possibility of the integration of local visual features into a global shape in the absence of awareness and, likewise, they suggest an early -subliminal- construction of the illusory shape, implying that feedback projections from higher to lower visual areas are not crucial in the construction of the illusory form.
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Affiliation(s)
- Mikel Jimenez
- Departamento de Psicología Básica 1, Facultad de Psicología, UNED, C/Juan del Rosal 10, 28040 Madrid, Spain.
| | - Pedro R Montoro
- Departamento de Psicología Básica 1, Facultad de Psicología, UNED, C/Juan del Rosal 10, 28040 Madrid, Spain
| | - Dolores Luna
- Departamento de Psicología Básica 1, Facultad de Psicología, UNED, C/Juan del Rosal 10, 28040 Madrid, Spain
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Abstract
Recent findings in neuroscience strongly suggest that an object's features (e.g., its color, texture, shape, etc.) are represented in separate areas of the visual cortex. Although represented in separate neuronal areas, somehow the feature representations are brought together as a single, unified object of visual consciousness. This raises a question of binding: how do neural activities in separate areas of the visual cortex function to produce a feature-unified object of visual consciousness? Several prominent neuroscientists have adopted neural synchrony and attention-based approaches to explain object feature binding. I argue that although neural synchrony and/or attentional mechanisms might function to disambiguate an object's features, it is difficult to see how either of these mechanisms could fully explain the unity of an object's features at the level of visual consciousness. After presenting a detailed critique of neural synchrony and attention-based approaches to object feature binding, I propose interactive hierarchical structuralism (IHS) . This view suggests that a unified percept (i.e., a feature-unified object of visual consciousness) is not reducible to the activity of any cognitive capacity or to any localized neural area, but emerges out of the interaction of visual information organized by spatial structuring capacities correlated with lower, higher, and intermediate levels of the visual hierarchy. After clarifying different notions of emergence and elaborating evidence for IHS, I discuss how IHS can be tested through transcranial magnetic stimulation and masking. In the final section I present some further implications/advantages of IHS.
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Banica T, Schwarzkopf DS. Induction of Kanizsa Contours Requires Awareness of the Inducing Context. PLoS One 2016; 11:e0161177. [PMID: 27518569 PMCID: PMC4982671 DOI: 10.1371/journal.pone.0161177] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 08/01/2016] [Indexed: 11/18/2022] Open
Abstract
It remains unknown to what extent the human visual system interprets information about complex scenes without conscious analysis. Here we used visual masking techniques to assess whether illusory contours (Kanizsa shapes) are perceived when the inducing context creating this illusion does not reach awareness. In the first experiment we tested perception directly by having participants discriminate the orientation of an illusory contour. In the second experiment, we exploited the fact that the presence of an illusory contour enhances performance on a spatial localization task. Moreover, in the latter experiment we also used a different masking method to rule out the effect of stimulus duration. Our results suggest that participants do not perceive illusory contours when they are unaware of the inducing context. This is consistent with theories of a multistage, recurrent process of perceptual integration. Our findings thus challenge some reports, including those from neurophysiological experiments in anaesthetized animals. Furthermore, we discuss the importance to test the presence of the phenomenal percept directly with appropriate methods.
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Affiliation(s)
- Theodora Banica
- Experimental Psychology, University College London, 26 Bedford Way, London, United Kingdom
| | - D. Samuel Schwarzkopf
- Experimental Psychology, University College London, 26 Bedford Way, London, United Kingdom
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London, United Kingdom
- * E-mail:
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Early suppression effect in human primary visual cortex during Kanizsa illusion processing: A magnetoencephalographic evidence. Vis Neurosci 2016; 33:E007. [PMID: 27485162 DOI: 10.1017/s0952523816000031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Detection of illusory contours (ICs) such as Kanizsa figures is known to depend primarily upon the lateral occipital complex. Yet there is no universal agreement on the role of the primary visual cortex in this process; some existing evidence hints that an early stage of the visual response in V1 may involve relative suppression to Kanizsa figures compared with controls. Iso-oriented luminance borders, which are responsible for Kanizsa illusion, may evoke surround suppression in V1 and adjacent areas leading to the reduction in the initial response to Kanizsa figures. We attempted to test the existence, as well as to find localization and timing of the early suppression effect produced by Kanizsa figures in adult nonclinical human participants. We used two sizes of visual stimuli (4.5 and 9.0°) in order to probe the effect at two different levels of eccentricity; the stimuli were presented centrally in passive viewing conditions. We recorded magnetoencephalogram, which is more sensitive than electroencephalogram to activity originating from V1 and V2 areas. We restricted our analysis to the medial occipital area and the occipital pole, and to a 40-120 ms time window after the stimulus onset. By applying threshold-free cluster enhancement technique in combination with permutation statistics, we were able to detect the inverted IC effect-a relative suppression of the response to the Kanizsa figures compared with the control stimuli. The current finding is highly compatible with the explanation involving surround suppression evoked by iso-oriented collinear borders. The effect may be related to the principle of sparse coding, according to which V1 suppresses representations of inner parts of collinear assemblies as being informationally redundant. Such a mechanism is likely to be an important preliminary step preceding object contour detection.
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Abstract
It has been suggested that contour junctions may be used as cues for occlusion. Ecologically, T-junctions and L-junctions are concurrent with situations of occlusion: they arise when the bounding contour of the occluding surface intersects with that of the occluded surface. However, there are other image properties that can be used as cues for occlusion. Here the role of junctions is directly compared with other occlusion cues—specifically, relatability and surface-similarity—in the emergence of amodal completion and illusory contour perception. Stimuli have been constructed that differ only in the junction structure, with the other occlusion cues kept unchanged. L-junctions and T-junctions were eliminated from the image or manipulated so as to be locally inconsistent with the (still valid) global occlusion interpretation. Although the other occlusion cues of relatability and surface similarity still existed in the image, subjects reported not perceiving illusory contours or amodal completion in junction-manipulated images. Junction manipulation also affected the perceived stereoscopic depth and motion of image regions, depending on whether they were perceived to amodally complete with a disjoint region in the image. These results are interpreted in terms of the role of junctions in the processes of surface completion and contour matching. It is proposed that junctions, being a local cue for occlusion, are used to launch completion processes. Other, more global occlusion cues, such as relatability, play a part at a later stage, once completion processes have been launched.
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Affiliation(s)
- N Rubin
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
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Abstract
We investigated whether 4-month-old infants are capable of perceiving illusory contours produced by the Kanizsa-square display, first introduced by Prazdny (1983, Perception & Psychophysics34 403–404), which tests whether a viewer perceives the illusory contour in the absence of brightness contrast (illusory brightness). Because the illusory square appears to move across the computer screen and infants are attracted to motion, this display holds their interest. In experiment 1, 4-month-old infants were tested for their ability to distinguish between a continuously moving illusory square and a continuously moving control display in which the pacman elements were rotated so that the perception of subjective contours did not occur. Data analysis revealed a significant preference for the subjective contour display. In experiment 2, habituation-dishabituation was used with 4-month-old infants. They were tested for their ability to discriminate between the illusory Kanizsa square that continuously moved back and forth and an illusory square which changed positions randomly. Although the infants did not show differences in dishabituation as a function of the habituation display, they looked significantly longer at the continuously moving display.
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Affiliation(s)
- Michael Kavsek
- Department of Psychology, University of Bonn, Romerstrasse 164, D 53117 Bonn, Germany.
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Parietal cortex mediates perceptual Gestalt grouping independent of stimulus size. Neuroimage 2016; 133:367-377. [DOI: 10.1016/j.neuroimage.2016.03.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/22/2016] [Accepted: 03/04/2016] [Indexed: 11/19/2022] Open
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Grossberg S. How Does the Cerebral Cortex Work? Development, Learning, Attention, and 3-D Vision by Laminar Circuits of Visual Cortex. ACTA ACUST UNITED AC 2016; 2:47-76. [PMID: 17715598 DOI: 10.1177/1534582303002001003] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A key goal of behavioral and cognitive neuroscience is to link brain mechanisms to behavioral functions. The present article describes recent progress toward explaining how the visual cortex sees. Visual cortex, like many parts of perceptual and cognitive neocortex, is organized into six main layers of cells, as well as characteristic sublamina. Here it is proposed how these layered circuits help to realize processes of development, learning, perceptual grouping, attention, and 3-D vision through a combination of bottom-up, horizontal, and top-down interactions. A main theme is that the mechanisms which enable development and learning to occur in a stable way imply properties of adult behavior. These results thus begin to unify three fields: infant cortical development, adult cortical neurophysiology and anatomy, and adult visual perception. The identified cortical mechanisms promise to generalize to explain how other perceptual and cognitive processes work.
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Kirjakovski A, Matsumoto E. Numerosity underestimation in sets with illusory contours. Vision Res 2016; 122:34-42. [PMID: 27038561 DOI: 10.1016/j.visres.2016.03.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 03/16/2016] [Accepted: 03/18/2016] [Indexed: 10/22/2022]
Abstract
People underestimate the numerosity of collections in which a few dots are connected in pairs by task-irrelevant lines. Such configural processing suggests that visual numerosity depends on the perceived scene segments, rather than on the perceived total area occupied by a collection. However, a methodology that uses irrelevant line connections may also introduce unnecessary distraction and variety, or obscure the perception of task-relevant items, given the saliency of the lines. To avoid such potentially confounding variables, we conducted four experiments where the line-connected dots were replaced with collinear inducers of Kanizsa-type illusory contours. Our participants had to compare two simultaneously presented collections and choose the more numerous one. Displays comprised c-shaped inducers and disks (Experiment 1), c-shaped inducers only (Experiments 2 and 4), or closed inducers (Experiment 3). One display always showed a 12- (Experiments 1-3) or 48-item reference pattern (Experiment 4); the other was a test pattern with numerosity varying between 9 and 15 (Experiments 1-3) or 36-60 items (Experiment 4). By manipulating the number of illusory contours in the test patterns, the level of connectedness increased or decreased respectively. The fitted psychometric functions revealed an underestimation that increased with the number of illusory contours in Experiments 1 and 2, but was absent in Experiments 3 and 4, where illusory contours were more difficult to perceive or larger numerosities were used. Results corroborate claims that visual numerosity estimation depends on segmented inputs, but only within moderate numerical ranges.
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Affiliation(s)
- Atanas Kirjakovski
- Graduate School of Intercultural Studies, Kobe University, 1-2-1 Tsurukabuto, Nada-ku, Kobe 657-8501, Japan.
| | - Eriko Matsumoto
- Graduate School of Intercultural Studies, Kobe University, 1-2-1 Tsurukabuto, Nada-ku, Kobe 657-8501, Japan.
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Anken J, Knebel JF, Crottaz-Herbette S, Matusz PJ, Lefebvre J, Murray MM. Cue-dependent circuits for illusory contours in humans. Neuroimage 2016; 129:335-344. [DOI: 10.1016/j.neuroimage.2016.01.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/22/2015] [Accepted: 01/22/2016] [Indexed: 10/22/2022] Open
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Applying Transcranial Magnetic Stimulation (TMS) Over the Dorsal Visual Pathway Induces Schizophrenia-like Disruption of Perceptual Closure. Brain Topogr 2016; 29:552-60. [PMID: 27021230 DOI: 10.1007/s10548-016-0487-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 03/21/2016] [Indexed: 10/22/2022]
Abstract
Perceptual closure ability is postulated to depend upon rapid transmission of magnocellular information to prefrontal cortex via the dorsal stream. In contrast, illusory contour processing requires only local interactions within primary and ventral stream visual regions, such as lateral occipital complex. Schizophrenia is associated with deficits in perceptual closure versus illusory contours processing that is hypothesized to reflect impaired magnocellular/dorsal stream. Perceptual closure and illusory contours performance was evaluated in separate groups of 12 healthy volunteers during no TMS, and during repetitive 10 Hz rTMS stimulation over dorsal stream or vertex (TMS-vertex). Perceptual closure and illusory contours were performed in 11 schizophrenia patients, no TMS was applied in these patients. TMS effects were evaluated with repeated measures ANOVA across treatments. rTMS significantly increased perceptual closure identification thresholds, with significant difference between TMS-dorsal stream and no TMS. TMS-dorsal stream also significantly reduced perceptual closure but not illusory contours accuracy. Schizophrenia patients showed increased perceptual closure identification thresholds relative to controls in the no TMS condition, but similar to controls in the TMS-dorsal stream condition. Conclusions of this study are that magnocellular/dorsal stream input is critical for perceptual closure but not illusory contours performance, supporting both trickledown theories of normal perceptual closure function, and magnocellular/dorsal stream theories of visual dysfunction in schizophrenia.
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Erlikhman G, Gurariy G, Mruczek REB, Caplovitz GP. The neural representation of objects formed through the spatiotemporal integration of visual transients. Neuroimage 2016; 142:67-78. [PMID: 27033688 DOI: 10.1016/j.neuroimage.2016.03.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 03/15/2016] [Accepted: 03/17/2016] [Indexed: 11/18/2022] Open
Abstract
Oftentimes, objects are only partially and transiently visible as parts of them become occluded during observer or object motion. The visual system can integrate such object fragments across space and time into perceptual wholes or spatiotemporal objects. This integrative and dynamic process may involve both ventral and dorsal visual processing pathways, along which shape and spatial representations are thought to arise. We measured fMRI BOLD response to spatiotemporal objects and used multi-voxel pattern analysis (MVPA) to decode shape information across 20 topographic regions of visual cortex. Object identity could be decoded throughout visual cortex, including intermediate (V3A, V3B, hV4, LO1-2,) and dorsal (TO1-2, and IPS0-1) visual areas. Shape-specific information, therefore, may not be limited to early and ventral visual areas, particularly when it is dynamic and must be integrated. Contrary to the classic view that the representation of objects is the purview of the ventral stream, intermediate and dorsal areas may play a distinct and critical role in the construction of object representations across space and time.
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Affiliation(s)
| | | | - Ryan E B Mruczek
- Department of Psychology, University of Nevada, Reno, USA; Department of Psychology, Worcester State University, USA
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