1
|
Machida I, Shishikura M, Yamane Y, Sakai K. Representation of Natural Contours by a Neural Population in Monkey V4. eNeuro 2024; 11:ENEURO.0445-23.2024. [PMID: 38423791 PMCID: PMC10946029 DOI: 10.1523/eneuro.0445-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/18/2024] [Accepted: 02/22/2024] [Indexed: 03/02/2024] Open
Abstract
The cortical visual area, V4, has been considered to code contours that contribute to the intermediate-level representation of objects. The neural responses to the complex contour features intrinsic to natural contours are expected to clarify the essence of the representation. To approach the cortical coding of natural contours, we investigated the simultaneous coding of multiple contour features in monkey (Macaca fuscata) V4 neurons and their population-level representation. A substantial number of neurons showed significant tuning for two or more features such as curvature and closure, indicating that a substantial number of V4 neurons simultaneously code multiple contour features. A large portion of the neurons responded vigorously to acutely curved contours that surrounded the center of classical receptive field, suggesting that V4 neurons tend to code prominent features of object contours. The analysis of mutual information (MI) between the neural responses and each contour feature showed that most neurons exhibited similar magnitudes for each type of MI, indicating that many neurons showing the responses depended on multiple contour features. We next examined the population-level representation by using multidimensional scaling analysis. The neural preferences to the multiple contour features and that to natural stimuli compared with silhouette stimuli increased along with the primary and secondary axes, respectively, indicating the contribution of the multiple contour features and surface textures in the population responses. Our analyses suggested that V4 neurons simultaneously code multiple contour features in natural images and represent contour and surface properties in population.
Collapse
Affiliation(s)
- Itsuki Machida
- Department of Computer Science, University of Tsukuba, Tsukuba 305-8573, Japan
| | - Motofumi Shishikura
- Department of Computer Science, University of Tsukuba, Tsukuba 305-8573, Japan
| | - Yukako Yamane
- Neural Computation Unit, Okinawa Institute of Science and Technology, Okinawa 904-0495, Japan
| | - Ko Sakai
- Department of Computer Science, University of Tsukuba, Tsukuba 305-8573, Japan
| |
Collapse
|
2
|
Xu Y, Vignali L, Sigismondi F, Crepaldi D, Bottini R, Collignon O. Similar object shape representation encoded in the inferolateral occipitotemporal cortex of sighted and early blind people. PLoS Biol 2023; 21:e3001930. [PMID: 37490508 PMCID: PMC10368275 DOI: 10.1371/journal.pbio.3001930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 06/23/2023] [Indexed: 07/27/2023] Open
Abstract
We can sense an object's shape by vision or touch. Previous studies suggested that the inferolateral occipitotemporal cortex (ILOTC) implements supramodal shape representations as it responds more to seeing or touching objects than shapeless textures. However, such activation in the anterior portion of the ventral visual pathway could be due to the conceptual representation of an object or visual imagery triggered by touching an object. We addressed these possibilities by directly comparing shape and conceptual representations of objects in early blind (who lack visual experience/imagery) and sighted participants. We found that bilateral ILOTC in both groups showed stronger activation during a shape verification task than during a conceptual verification task made on the names of the same manmade objects. Moreover, the distributed activity in the ILOTC encoded shape similarity but not conceptual association among objects. Besides the ILOTC, we also found shape representation in both groups' bilateral ventral premotor cortices and intraparietal sulcus (IPS), a frontoparietal circuit relating to object grasping and haptic processing. In contrast, the conceptual verification task activated both groups' left perisylvian brain network relating to language processing and, interestingly, the cuneus in early blind participants only. The ILOTC had stronger functional connectivity to the frontoparietal circuit than to the left perisylvian network, forming a modular structure specialized in shape representation. Our results conclusively support that the ILOTC selectively implements shape representation independently of visual experience, and this unique functionality likely comes from its privileged connection to the frontoparietal haptic circuit.
Collapse
Affiliation(s)
- Yangwen Xu
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| | - Lorenzo Vignali
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
- International School for Advanced Studies (SISSA), Trieste, Italy
| | | | - Davide Crepaldi
- International School for Advanced Studies (SISSA), Trieste, Italy
| | - Roberto Bottini
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
| | - Olivier Collignon
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Trento, Italy
- Psychological Sciences Research Institute (IPSY) and Institute of NeuroScience (IoNS), University of Louvain, Louvain-la-Neuve, Belgium
- School of Health Sciences, HES-SO Valais-Wallis, The Sense Innovation and Research Center, Lausanne and Sion, Switzerland
| |
Collapse
|
3
|
Wei L, Li X, Huang L, Liu Y, Hu L, Shen W, Ding Q, Liang P. An fMRI study of visual geometric shapes processing. Front Neurosci 2023; 17:1087488. [PMID: 37008223 PMCID: PMC10062448 DOI: 10.3389/fnins.2023.1087488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/28/2023] [Indexed: 03/18/2023] Open
Abstract
Cross-modal correspondence has been consistently evidenced between shapes and other sensory attributes. Especially, the curvature of shapes may arouse the affective account, which may contribute to understanding the mechanism of cross-modal integration. Hence, the current study used the functional magnetic resonance imaging (fMRI) technique to examine brain activity’s specificity when people view circular and angular shapes. The circular shapes consisted of a circle and an ellipse, while the angular shapes consisted of a triangle and a star. Results show that the brain areas activated by circular shapes mainly involved the sub-occipital lobe, fusiform gyrus, sub and middle occipital gyrus, and cerebellar VI. The brain areas activated by angular shapes mainly involve the cuneus, middle occipital gyrus, lingual gyrus, and calcarine gyrus. The brain activation patterns of circular shapes did not differ significantly from those of angular shapes. Such a null finding was unexpected when previous cross-modal correspondence of shape curvature was considered. The different brain regions detected by circular and angular shapes and the potential explanations were discussed in the paper.
Collapse
Affiliation(s)
- Liuqing Wei
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China
- Brain and Cognition Research Center, Faculty of Education, Hubei University, Wuhan, China
| | - Xueying Li
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China
| | - Lina Huang
- Imaging Department, Changshu No. 2 People’s Hospital, The Clinical Medical College Affiliated to Xuzhou Medical University, Changshu, China
| | - Yuansheng Liu
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China
| | - Luming Hu
- Department of Psychology, School of Arts and Sciences, Beijing Normal University, Zhuhai, China
| | - Wenbin Shen
- Imaging Department, Changshu No. 2 People’s Hospital, The Clinical Medical College Affiliated to Xuzhou Medical University, Changshu, China
| | - Qingguo Ding
- Imaging Department, Changshu No. 2 People’s Hospital, The Clinical Medical College Affiliated to Xuzhou Medical University, Changshu, China
- *Correspondence: Qingguo Ding,
| | - Pei Liang
- Department of Psychology, Faculty of Education, Hubei University, Wuhan, China
- Brain and Cognition Research Center, Faculty of Education, Hubei University, Wuhan, China
- Imaging Department, Changshu No. 2 People’s Hospital, The Clinical Medical College Affiliated to Xuzhou Medical University, Changshu, China
- Pei Liang,
| |
Collapse
|
4
|
Ayzenberg V, Behrmann M. Does the brain's ventral visual pathway compute object shape? Trends Cogn Sci 2022; 26:1119-1132. [PMID: 36272937 DOI: 10.1016/j.tics.2022.09.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 09/22/2022] [Accepted: 09/26/2022] [Indexed: 11/11/2022]
Abstract
A rich behavioral literature has shown that human object recognition is supported by a representation of shape that is tolerant to variations in an object's appearance. Such 'global' shape representations are achieved by describing objects via the spatial arrangement of their local features, or structure, rather than by the appearance of the features themselves. However, accumulating evidence suggests that the ventral visual pathway - the primary substrate underlying object recognition - may not represent global shape. Instead, ventral representations may be better described as a basis set of local image features. We suggest that this evidence forces a reevaluation of the role of the ventral pathway in object perception and posits a broader network for shape perception that encompasses contributions from the dorsal pathway.
Collapse
Affiliation(s)
- Vladislav Ayzenberg
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Psychology Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
| | - Marlene Behrmann
- Neuroscience Institute, Carnegie Mellon University, Pittsburgh, PA 15213, USA; Psychology Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA; The Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| |
Collapse
|
5
|
Ayzenberg V, Kamps FS, Dilks DD, Lourenco SF. Skeletal representations of shape in the human visual cortex. Neuropsychologia 2022; 164:108092. [PMID: 34801519 PMCID: PMC9840386 DOI: 10.1016/j.neuropsychologia.2021.108092] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 11/07/2021] [Accepted: 11/17/2021] [Indexed: 01/17/2023]
Abstract
Shape perception is crucial for object recognition. However, it remains unknown exactly how shape information is represented and used by the visual system. Here, we tested the hypothesis that the visual system represents object shape via a skeletal structure. Using functional magnetic resonance imaging (fMRI) and representational similarity analysis (RSA), we found that a model of skeletal similarity explained significant unique variance in the response profiles of V3 and LO. Moreover, the skeletal model remained predictive in these regions even when controlling for other models of visual similarity that approximate low-to high-level visual features (i.e., Gabor-jet, GIST, HMAX, and AlexNet), and across different surface forms, a manipulation that altered object contours while preserving the underlying skeleton. Together, these findings shed light on shape processing in human vision, as well as the computational properties of V3 and LO. We discuss how these regions may support two putative roles of shape skeletons: namely, perceptual organization and object recognition.
Collapse
Affiliation(s)
- Vladislav Ayzenberg
- Department of Psychology, Carnegie Mellon University, USA,Corresponding author: (V. Ayzenberg)
| | - Frederik S. Kamps
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, USA
| | | | - Stella F. Lourenco
- Department of Psychology, Emory University, USA,Corresponding author: (S.F. Lourenco)
| |
Collapse
|