Near-perfect prediction of reaction time for face gender judgments based on activity in ventral temporal cortex

Our mind can represent various objects from the physical world metaphorically into an abstract and complex high-dimensional object space, with a finite number of orthogonal axes encoding critical object features. Previous fMRI studies have shown that the middle fusiform sulcus in the ventral temporal cortex separates the real-world small-size map from the large-size map. Here we asked whether the feature of objects' real-world size constructed an axis of object space with deep convolutional neural networks (DCNNs) based on three criteria of sensitivity, independence and necessity that are impractical to be examined altogether with traditional approaches. A principal component analysis on features extracted by the DCNNs showed that objects' real-world size was encoded by an independent component, and the removal of this component significantly impaired DCNN's performance in recognizing objects. By manipulating stimuli, we found that the shape and texture of objects, rather than retina size, co-occurrence and task demands, accounted for the representation of the real-world size in the DCNNs. A follow-up fMRI experiment on humans further demonstrated that the shape, but not the texture, was used to infer the real-world size of objects in humans. In short, with both computational modeling and empirical human experiments, our study provided the first evidence supporting the feature of objects' real-world size as an axis of object space, and devised a novel paradigm for future exploring the structure of object space.

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The nature of the animacy organization in human ventral temporal cortex

eLife ◽

10.7554/elife.47142 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 4

Author(s):

Sushrut Thorat ◽

Daria Proklova ◽

Marius V Peelen

Keyword(s):

Neural Networks ◽

Convolutional Neural Networks ◽

Temporal Cortex ◽

Behavioral Experiments ◽

Diagnostic Features ◽

Social Agents ◽

Independent Components ◽

Ventral Temporal Cortex ◽

Organizing Principles ◽

The Continuum

The principles underlying the animacy organization of the ventral temporal cortex (VTC) remain hotly debated, with recent evidence pointing to an animacy continuum rather than a dichotomy. What drives this continuum? According to the visual categorization hypothesis, the continuum reflects the degree to which animals contain animal-diagnostic features. By contrast, the agency hypothesis posits that the continuum reflects the degree to which animals are perceived as (social) agents. Here, we tested both hypotheses with a stimulus set in which visual categorizability and agency were dissociated based on representations in convolutional neural networks and behavioral experiments. Using fMRI, we found that visual categorizability and agency explained independent components of the animacy continuum in VTC. Modeled together, they fully explained the animacy continuum. Finally, clusters explained by visual categorizability were localized posterior to clusters explained by agency. These results show that multiple organizing principles, including agency, underlie the animacy continuum in VTC.

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Birds of a Feather Flock Together: Experience-Driven Formation of Visual Object Categories in Human Ventral Temporal Cortex

PLoS ONE ◽

10.1371/journal.pone.0003995 ◽

2008 ◽

Vol 3 (12) ◽

pp. e3995 ◽

Cited By ~ 19

Author(s):

Marieke van der Linden ◽

Jaap M. J. Murre ◽

Miranda van Turennout

Keyword(s):

Temporal Cortex ◽

Visual Object ◽

Object Categories ◽

Ventral Temporal Cortex

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Feature Diagnosticity Affects Representations of Novel and Familiar Objects

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_00661 ◽

2014 ◽

Vol 26 (12) ◽

pp. 2735-2749 ◽

Cited By ~ 8

Author(s):

Nina S. Hsu ◽

Margaret L. Schlichting ◽

Sharon L. Thompson-Schill

Keyword(s):

Fruits And Vegetables ◽

Temporal Cortex ◽

Familiar Object ◽

Behavioral Effects ◽

Diagnostic Features ◽

Novel Objects ◽

Human Participants ◽

Ventral Temporal Cortex ◽

Concept Representations ◽

The Impact

Many features can describe a concept, but only some features define a concept in that they enable discrimination of items that are instances of a concept from (similar) items that are not. We refer to this property of some features as feature diagnosticity. Previous work has described the behavioral effects of feature diagnosticity, but there has been little work on explaining why and how these effects arise. In this study, we aimed to understand the impact of feature diagnosticity on concept representations across two complementary experiments. In Experiment 1, we manipulated the diagnosticity of one feature, color, for a set of novel objects that human participants learned over the course of 1 week. We report behavioral and neural evidence that diagnostic features are likely to be automatically recruited during remembering. Specifically, individuals activated color-selective regions of ventral temporal cortex (specifically, left fusiform gyrus and left inferior temporal gyrus) when thinking about the novel objects, although color information was never explicitly probed during the task. Moreover, multiple behavioral and neural measures of the effects of feature diagnosticity were correlated across participants. In Experiment 2, we examined relative color association in familiar object categories, which varied in feature diagnosticity (fruits and vegetables, household items). Taken together, these results offer novel insights into the neural mechanisms underlying concept representations by demonstrating that automatic recruitment of diagnostic information gives rise to behavioral effects of feature diagnosticity.

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