Biology subjects

Kidder, A.

Publications and source records attributed to Kidder, A..

6 recordsLinked to original sources

bioRxiv2025

Developmental prosopagnosics have normal spatial integration in posterior ventral face-selective regions

Population receptive field (pRF) mapping is an influential neuroimaging technique used to estimate the region of visual space modulating the response of a neuronal population. While pRF mapping has advanced our understanding of visual cortical organization, evidence linking variation in pRF properties to behavioral performance remains limited. One of the most compelling pRF-to-behavior relationships has emerged from research into developmental prosopagnosia (DP). Individuals with DP have severe deficits in facial identity recognition sometimes linked to diminished holistic processing of faces. This perceptual deficit could be explained at the neural level by abnormally small pRFs in face-selective regions that restrict spatial integration of the face information. This hypothesis is supported by data from a small group of DPs but needs to be rigorously evaluated in a larger sample. Here, we measured pRF properties in 20 individuals with DP and 20 controls using a stimulus designed to robustly activate both low- and high-level visual areas. Consistent with previous studies, DPs exhibited weaker face selectivity in core ventral face-selective areas. Crucially, however, across the visual processing hierarchy - from early visual cortex, to intermediate visual areas, and face-selective areas - DPs and controls exhibited remarkable similarity in pRF properties, including pRF size, visual field coverage, and the distribution of pRF centers. Using a larger sample and the latest methods for mapping and modeling pRFs, these results challenge theories attributing DP to reduced spatial integration in face-selective regions. This underscores the need to explore alternative neural mechanisms of DP and to re-evaluate links between pRF properties and behavior more broadly.

neuroscience↗

bioRxiv2024

Mapping object space dimensions: new insights from temporal dynamics

How is object information organized in high-level visual cortex? Recently, a comprehensive model of object space in macaques was proposed, defined by the orthogonal axes of animacy and aspect ratio (Bao et al., 2020). However, when using stimuli that dissociated category, animacy, and aspect ratio in humans, no tuning of aspect ratio was observed in fMRI data (Yargholi & Op de Beeck, 2023). This difference could be a result of different stimuli, the limited temporal resolution of fMRI, or information available about the presented stimuli. Here, we asked if and when information about aspect ratio, animacy, and category is available over time. We collected whole-brain electroencephalography (EEG) data while participants (N = 20) viewed the stimulus set used by Yargholi & Op de Beeck (2023). To mask object details and increase reliance on shape information, we also presented silhouette versions of the stimuli. Stimuli were presented in 5Hz streams using rapid serial visual presentation, with intact and silhouette stimuli sets were shown in separate streams. Using standard multivariate decoding pipelines and representational similarity analysis, we found that aspect ratio, category, and animacy were represented during visual object processing. The dominant dimension was modulated by stimulus type, demonstrating that the observable dimensions of object space depend on the nature of the stimuli presented. Taken together, these findings demonstrate that aspect ratio is represented during object processing, however earlier and more transiently than categorical dimensions, such as animacy. By focusing on underlying temporal dynamics, our results provide clear new insights into the contradicting findings reported in previous work and reveal a more nuanced understanding of how object space evolves over time.

neuroscience↗

bioRxiv2022

Distributed cortical regions for the recall of people, places and objects

Human medial parietal cortex (MPC) is recruited during multiple cognitive processes. Previously, we demonstrated regions specific to recall of people or places and proposed that the functional organization of MPC mirrors the category selectivity defining the medial-lateral axis of ventral temporal cortex (VTC). However, prior work considered recall of people and places only and VTC also shows object-selectivity sandwiched between face- and scene-selective regions. Here, we tested a strong prediction of our proposal: like VTC, MPC should show a region specifically recruited during object recall, and its relative cortical position should mirror the one of VTC. While responses during people and place recall showed a striking replication of prior findings, we did not observe any evidence for object-recall effects within MPC, which differentiates it from the spatial organization in VTC. Importantly, beyond MPC, robust recall-effects were observed for people, places, and objects on the lateral surface of the brain. Place-recall effects were present in the angular gyrus, frontal eye fields and peripheral portions of early visual cortex, whereas people-recall selectively drove response in the right posterior superior temporal sulcus. Object-recall effects were largely restricted to a region posterior to left somatosensory cortex, in the vicinity of the supramarginal gyrus. Taken together, these data demonstrate that while there are distributed regions active during recall of people, places and objects, the functional organization of MPC does not mirror the medial-lateral axis of VTC but reflects only the most salient features of that axis - namely representations of people and places. Significance statementHuman medial parietal cortex (MPC) is recruited during multiple cognitive processes. Recently, we proposed a framework for interpreting the functional organization of MPC by suggesting that it reflects the categorical preferences for people and places that is evident also in ventral temporal cortex (VTC). Because VTC also exhibits selectivity for objects, we here extend this framework to test whether MPC also shows object selectivity during recall. Robust people and place recall effects were evident in MPC, but we found no evidence for object-recall within MPC, suggesting that MPC and VTC are not mirror-copies of each other. Together, these data suggest that the functional organization of MPC reflects the most salient categorical representations within VTC for people and places.

neuroscience↗

bioRxiv2022

THINGS-data: A multimodal collection of large-scale datasets for investigating object representations in brain and behavior

Understanding object representations requires a broad, comprehensive sampling of the objects in our visual world with dense measurements of brain activity and behavior. Here we present THINGS-data, a multimodal collection of large-scale neuroimaging and behavioral datasets in humans, comprising densely-sampled functional MRI and magnetoencephalographic recordings, as well as 4.70 million similarity judgments in response to thousands of photographic images for up to 1,854 object concepts. THINGS-data is unique in its breadth of richly-annotated objects, allowing for testing countless hypotheses at scale while assessing the reproducibility of previous findings. Beyond the unique insights promised by each individual dataset, the multimodality of THINGS-data allows combining datasets for a much broader view into object processing than previously possible. Our analyses demonstrate the high quality of the datasets and provide five examples of hypothesis-driven and data-driven applications. THINGS-data constitutes the core public release of the THINGS initiative (https://things-initiative.org) for bridging the gap between disciplines and the advancement of cognitive neuroscience.

neuroscience↗

bioRxiv2019

Distinct subdivisions of human medial parietal cortex are recruited differentially for memory recall of places and people

Human medial parietal cortex (MPC) is implicated in multiple cognitive processes including memory recall, visual scene processing and navigation. It is also considered a core component of the default mode network. Here, we combine fMRI data across three independent experiments to demonstrate distinct subdivisions of MPC that are selectively recruited during memory recall of either specific places or specific people. First, distinct regions of MPC were identified on the basis of differential functional connectivity with medial and lateral regions of anterior ventral temporal cortex (VTC). Second, these same medial regions exhibited differential responses to the visual presentation of different stimulus categories, with clear preferences for scenes and faces, respectively. Third, and most critically, these regions were selectively recruited during either place or people memory recall. These subdivisions also showed a striking relationship with ventral and dorsal divisions of the default mode network. Taken together, these data reveal distinct subdivisions within MPC for the recall of places and people and moreover, suggest that the organizing principle defining the medial-lateral axis of VTC is reflected in MPC, but in the context of memory recall.

neuroscience↗

bioRxiv2019

THINGS: A database of 1,854 object concepts and more than 26,000 naturalistic object images

In recent years, the use of a large number of object concepts and naturalistic object images has been growing enormously in cognitive neuroscience research. Classical databases of object concepts are based mostly on a manually-curated set of concepts. Further, databases of naturalistic object images typically consist of single images of objects cropped from their background, or a large number of uncontrolled naturalistic images of varying quality, requiring elaborate manual image curation. Here we provide a set of 1,854 diverse object concepts sampled systematically from concrete picturable and nameable nouns in the American English language. Using these object concepts, we conducted a large-scale web image search to compile a database of 26,107 high-quality naturalistic images of those objects, with 12 or more object images per concept and all images cropped to square size. Using crowdsourcing, we provide higher-level category membership for the 27 most common categories and validate them by relating them to representations in a semantic embedding derived from large text corpora. Finally, by feeding images through a deep convolutional neural network, we demonstrate that they exhibit high selectivity for different object concepts, while at the same time preserving variability of different object images within each concept. Together, the THINGS database provides a rich resource of object concepts and object images and offers a tool for both systematic and large-scale naturalistic research in the fields of psychology, neuroscience, and computer science.

neuroscience↗