Biology subjects

Cortinovis, D.

Publications and source records attributed to Cortinovis, D..

3 recordsLinked to original sources

bioRxiv2026

Object dimensions underlying food representations in visual cortex

Recent work has revealed two food-selective areas in the lateral and ventromedial occipitotemporal cortex (OTC). These studies have shown that food selectivity in these regions cannot be explained by mid-level features like shape, texture, or colour but differences in their representational content remain unclear. Across two fMRI experiments conducted in the same group of participants, we characterized the dimensions underlying food representations in lateral and ventral OTC by examining the contribution of action-related object properties, such as manipulability, relevant to object interaction, and visual features, such as colour and ensemble statistics, relevant to object recognition. Our results reveal a clear dissociation between lateral and ventral OTC, indicating that food representations in these regions reflect distinct computational constraints. In lateral OTC, food representations were primarily associated with action-related properties shared between food and other graspable objects, whereas in ventral OTC, food representations were sensitive to surface object properties, such as colour and ensemble configuration. Consistent with this distinction, lateral OTC showed greater sensitivity to individual objects against distinctive background and responded equally to colour and greyscale stimuli, while ventral OTC exhibited greater sensitivity to coloured stimuli and ensembles with no distinctive background. Finally, topographic artificial neural networks implementing architectural constraints meant to capture OTC spatial organization similarly exhibited two dissociable clusters of food-selective units based on sensitivity to ensemble statistics. Together, these findings suggest that lateral food representations reflect action-relevant properties shared with other manipulable objects, whereas ventral food representations arise from surface-based visual features critical for food identification.

neuroscience↗

bioRxiv2026

Encoding models uncover fine-grained feature selectivity for bodies, hands and tools

Category-selective areas in the occipitotemporal cortex (OTC) are typically characterized by broad tuning, yet neuroimaging suggests a finer-grained organization reflecting distinct computational roles. We combined image-level fMRI with artificial neural network (ANN)-based encoding models to investigate the selectivity and feature sensitivity of category-selective areas in ventral and lateral OTC. Using densely sampled fMRI data in three participants across six sessions, we identified functional dissociations between body, hand, and tool responses at the individual image level. Area-specific encoding models accurately predicted responses to millions of novel images, maintaining clear category preferences. Importantly, comparisons between models trained on areas selective for the same category revealed distinct feature sensitivities consistent with the areas anatomical location and hemispheric lateralization. These findings provide evidence for fine-grained specialization within OTC and demonstrate how ANN-based encoding models can uncover the computational, feature-level basis of category selectivity.

neuroscience↗

bioRxiv2025

Investigating action topography in visual cortex and deep artificial neural networks

High-level visual cortex contains category-selective areas embedded within larger-scale topographic maps like animacy and real-world size. Here, we propose action as a key organizing factor shaping visual cortex topography and assess the ability of topographic deep artificial neural networks (DANNs) in capturing this organization. Using fMRI, we examined responses to images of body-parts and objects with different degrees of action properties. In left lateral occipitotemporal cortex, we identified a topographically-organized action gradient, with overlapping activations for bodies, hands, tools, and manipulable objects along a dorsal-posterior to ventral-anterior axis, culminating at the intersection of body parts and objects exhibiting higher action properties. Multivariate analyses confirmed action as a crucial organizing principle, while shape and animacy dominated ventral occipitotemporal cortex and DANNs, which exhibited no action-based organization. Our proposed action dimension serves as a further organizing principle of object categories, advancing understanding of visual cortex organization and its divergence from DANN-based models.

neuroscience↗