Characterising the behavioural and neural deficits of face recognition in developmental prosopagnosia

Developmental prosopagnosia (DP) is a neurodevelopmental condition in which there is an impairment in the ability to recognise face identities. The aim of this thesis was to explore the behavioural and neural deficits that characterise DP. Chapter 2 examined a current debate about the extent to which DP is face-specific or also affects the recognition of other objects. We asked whether objects that were perceived as faces (pareidolia) would also be affected in DP. Recognition of pareidolic objects was impaired in DP, but only if the objects had similar image properties to faces. This suggests that the underlying deficit in DP may reflect a disruption to processing image properties typically found in face images. In Chapters 3 and 4, we demonstrated that the deficit in DP extends to faces from different races and faces from different species. These findings suggest that the deficit in DP encompasses a range of configural and morphological structures. Chapters 5 and 6 explored the neural correlates of DP. Chapter 5 explored the identity recognition deficits in DP through investigating the neural signatures elicited by individual faces. We show that in contrast to neurotypical controls, DPs do not evidence identity discrimination at the neural level. Chapter 5 further showed that DP
is marked by alterations in the overall functional connectivity organization. Finally, Chapter 6 showed that, although global structural connectivity is not affected in DP, there were local reductions in connectivity within the temporal lobe. Taken together, the results from this thesis provide new insights into our understanding of the behavioural and neural mechanisms that underlie the deficits evident in DP.