Biology subjects

Duchaine, B.

Publications and source records attributed to Duchaine, B..

6 recordsLinked to original sources

bioRxiv2025

The first comprehensive case study of early-emerging prosopometamorphopsia

Prosopometamorphopsia (PMO) is a rare perceptual disorder characterized by facial distortions. This report presents the first thorough study of a case of PMO that emerged early in life. Zed has experienced lifelong, dynamic facial distortions in which features move, droop, disappear, expand, shrink, and rotate. He also experiences identity misrecognitions, in which he perceives familiar faces as strangers and vice versa (e.g., seeing his grandfather when viewing a young woman). Behavioral assessments indicate that Zeds distortions occur across viewpoints, visual field positions, picture-plane orientations, and visual angles. Neuropsychological testing revealed face identity recognition deficits, yet, despite his facial distortions, Zed can make accurate fine-grained perceptual judgments about facial age and sex. Structural MRI showed no lesions, but face-selectivity in two right posterior face-selective areas was reduced, and diffusion tensor imaging revealed lower white matter integrity in the left inferior fronto-occipital fasciculus. Zeds case offers new insights into early-emerging PMO, its manifestations, co-occurrence with other face-processing disorders, and underlying neural correlates.

neuroscience↗

bioRxiv2025

Overlooked neuroanatomical markers of face processing and developmental prosopagnosia in posteromedial cortex

Recent functional imaging studies implicate human posteromedial cortex (PMC)--composed of the posterior cingulate cortex, the precuneus, and retrosplenial cortex--in face processing. Separately, anatomical studies have identified previously overlooked cortical folds (sulci) in PMC associated with higher-level cognitive abilities. Here, we tested whether these newly identified sulci support face processing in neurotypical individuals and individuals with developmental prosopagnosia (DP). After manually labeling 1,642 sulci in 164 hemispheres, we first identified a gradient of face selectivity along the anterior-posterior axis of PMC that was consistent across three samples, including DP individuals. Second, we discovered a new anatomical locus in PMC that differed structurally and functionally between neurotypical and DP individuals. Finally, data-driven analysis revealed that right-hemisphere PMC sulcal morphology was associated with face recognition ability. These findings reveal a sulcal network in PMC that supports face processing, and they identify the first structural neuroanatomical marker of face processing deficits in PMC.

neuroscience↗

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↗

bioRxiv2025

Gyral crowns contribute to the cortical infrastructure of human face processing

Neuroanatomical features across spatial scales contribute to functional specialization and individual differences in behavior across species. Among species with gyrencephalic brains, gyral crown height, which measures a key aspect of the morphology of cortical folding, may represent an anatomical characteristic that importantly shapes neural function. Nevertheless, little is known about the relationship between functional selectivity and gyral crowns--especially in clinical populations. Here, we investigated this relationship and found that the size and gyral crown height of the middle, but not posterior, face-selective region on the fusiform gyrus (FG) was smaller in individuals with developmental prosopagnosia (DPs; N = 22, 68% female, aged 25-62) compared to neurotypical controls (NTs; N = 25, 60% females, aged 21-55), and this difference was related to face perception. Additional analyses replicated the relationship between gyral crowns and face selectivity in 1,053 NTs (55% females, aged 22-36). These results inform theoretical models of face processing while also providing a novel neuroanatomical feature contributing to the cortical infrastructure supporting face processing. Significance StatementUnderstanding how brain structure supports specialized brain functions is a central goal of neuroscience. Here, we identified a role of gyral crown height--an understudied cortical feature--in shaping the cortical infrastructure underlying face processing. By examining face-selective regions of the fusiform gyrus in both neurotypical individuals and those with developmental prosopagnosia, we demonstrate that reduced gyral crown height is associated with diminished face-selective region surface area and impaired face recognition ability. Furthermore, this structural-functional relationship extends to a large neurotypical sample of over 1,000 individuals, highlighting a generalizable link between cortical anatomy and functional specialization. These findings introduce a new neuroanatomical factor to theoretical models of face perception, which could extend to additional neurodevelopmental disorders and other cognitive tasks.

neuroscience↗

bioRxiv2022

Hominoid-specific sulcal variability is related to face perception ability

Human perception requires complex cortical networks that function at neuroanatomical scales of microns and temporal scales of milliseconds. Despite this complexity, what if just one morphological feature of the brain could predict perceptual ability? Here, we tested this hypothesis with pre-registered analyses of neuroanatomy and face perception in neurotypical controls (NTs) and individuals with developmental prosopagnosia (DPs). Results show that the length of the mid-fusiform sulcus (MFS), a hominoid-specific tertiary sulcus in ventral temporal cortex (VTC), was shorter in DPs than NTs. Furthermore, individual differences in MFS length in the right, but not left, hemisphere predicted individual differences in face perception. These results support theories linking brain structure and function to perception, as well as indicate that one feature - variability in MFS length - can predict face perception. Finally, these findings add to growing evidence supporting a role of morphological variability of late developing, tertiary sulci and individual differences in cognition.

neuroscience↗

bioRxiv2019

Music perception in acquired prosopagnosia: An anterior temporal syndrome for faces, voices, and music

BackgroundAcquired prosopagnosia is often associated with other deficits, such as dyschromatopsia and topographagnosia, from damage to adjacent perceptual networks. A recent study showed that some subjects with developmental prosopagnosia also have congenital amusia, but problems with music perception have not been described in the acquired variant.\n\nObjectiveOur goal was to determine if music perception was also impaired in subjects with acquired prosopagnosia, and if so, its anatomic correlate.\n\nMethodsWe studied eight subjects with acquired prosopagnosia, all of whom had extensive neuropsychological and neuroimaging testing. They performed a battery of tests evaluating pitch and rhythm processing, including the Montreal Battery for the Evaluation of Amusia.\n\nResultsThree of eight subjects with acquired prosopagnosia had impaired musical pitch perception while rhythm perception was spared. Two of the three also showed reduced musical memory. These three reported alterations in their emotional experience of music: one reported music anhedonia and aversion, while the remaining two had changes consistent with musicophilia. The lesions of these three subjects affected the right or bilateral temporal poles as well as the right amygdala and insula. None of the three prosopagnosic subjects with lesions limited to the inferior occipitotemporal cortex had impaired pitch perception or musical memory, or reported changes in music appreciation.\n\nConclusionTogether with the results of our previous studies of voice recognition, these findings indicate an anterior temporal agnosia syndrome that can include the amnestic variant of prosopagnosia, phonagnosia, and various alterations in music perception, including acquired amusia, reduced musical memory, and altered emotional responses to music.

neuroscience↗