Left hemisphere abnormalities in developmental prosopagnosia when looking at faces but not words

Abstract

<jats:title>Abstract</jats:title> <jats:p>Developmental prosopagnosia is a disorder characterized by profound and lifelong difficulties with face recognition in the absence of sensory or intellectual deficits or known brain injury. While there has been a surge in research on developmental prosopagnosia over the last decade and a half, the cognitive mechanisms behind the disorder and its neural underpinnings remain elusive. Most recently it has been proposed that developmental prosopagnosia may be a manifestation of widespread disturbance in neural migration which affects both face responsive brain regions as well as other category-sensitive visual areas. We present a combined behavioural and functional MRI study of face, object and word processing in a group of developmental prosopagnosics (N = 15). We show that developmental prosopagnosia is associated with reduced activation of core ventral face areas during perception of faces. The reductions were bilateral but tended to be more pronounced in the left hemisphere. As the first study to address category selectivity for word processing in developmental prosopagnosia, we do not, however, find evidence for reduced activation of the visual word form area during perception of orthographic material. We also find no evidence for reduced activation of the lateral occipital complex during perception of objects. These imaging findings correspond well with the behavioural performance of the developmental prosopagnosics, who show severe impairment for faces but normal reading and recognition of line drawings. Our findings suggest that a general deficit in neural migration across ventral occipito-temporal cortex is not a viable explanation for developmental prosopagnosia. The finding of left hemisphere involvement in our group of developmental prosopagnosics was at first surprising. However, a closer look at existing studies shows similar, but hitherto undiscussed, findings. These left hemisphere abnormalities seen in developmental prosopagnosia contrasts with lesion and imaging studies suggesting primarily right hemisphere involvement in acquired prosopagnosia, and this may reflect that the left hemisphere is important for the development of a normal face recognition network.</jats:p>

Investigating the influence of autism spectrum traits on face processing mechanisms in developmental prosopagnosia

“…This reduced face-selectivity is consistent with previous studies (Jiahui et al, 2018) and the left FFA reduction in selectivity is consistent with a recent DP study by Gerlach et al (2019).…”

“…In contrast to individuals with ASD, DPs frequently demonstrate reduced face selectivity in core (OFA, FFA, pSTS) and extended (anterior temporal) face regions during localizer tasks (Jiahui, Yang, and Duchaine, 2018;Gerlach, Klargaard, Alnaes, Kolskar, Karstoft, Westlye, and Starrfelt, 2019) as well as reduced FFA face adaptation (Furl, Garrido, Dolan, Driver, and Duchaine, 2011) and reduced resting-state connectivity amongst face-selective regions (Song et al, 2015) (but see: Behrmann, Avidan, Marotta, and Kimchi, 2005). Overall, ASD commonly implicates brain regions/networks involved in social cognition and social utilization of face information (e.g., pSTS) whereas DP is often associated with ventral occipito-temporal and anterior temporal regions more involved in face perception and identification (e.g., OFA, FFA, anterior temporal face area).…”

The Architect Who Lost the Ability to Imagine: The Cerebral Basis of Visual Imagery

“…Fitting with a role of the left fusiform gyrus in visual imagery, some developmental prosopagnosics appear to have functional abnormalities in this region [70][71][72] as well as reduced or absent mental imagery, not only for faces but also for objects and scenes [73]. Barton and Cherkasova [74] examined face imagery in prosopagnosics for featural imagery (questions regarding facial features, e.g., "Who has a wider mouth: Sophia Loren or Ingrid Bergman?")…”

Normal colour perception in developmental prosopagnosia

“…Another potential concern about the study is the lateralisation of neural abnormalities in DP. Most imaging studies suggest that DP individuals tend to have bilateral abnormalities 33 , 36 , but some may have unilateral abnormalities 78 . It is possible that in the case of unilateral abnormalities, colour perception deficits may only be detected by careful testing in the corresponding hemifield.…”