The Cognitive and Neural Basis of Developmental Prosopagnosia

Abstract

Developmental prosopagnosia (DP) is a severe impairment of visual face recognition in the absence of any apparent brain damage. The factors responsible for DP have not yet been fully identified. This article provides a selective review of recent studies investigating cognitive and neural processes that may contribute to the face recognition deficits in DP, focusing primarily on event-related brain potential (ERP) measures of face perception and recognition. Studies that measured the face-sensitive N170 component as a marker of perceptual face processing have shown that the perceptual discrimination between faces and non-face objects is intact in DP. Other N170 studies suggest that faces are not represented in the typical fashion in DP. Individuals with DP appear to have specific difficulties in processing spatial and contrast deviations from canonical upright visualperceptual face templates. The rapid detection of emotional facial expressions appears to be unaffected in DP. ERP studies of the activation of visual memory for individual faces and of the explicit identification of particular individuals have revealed differences between DPs and controls in the timing of these processes and in the links between visual face memory and explicit face recognition. These observations suggest that the speed and efficiency of information propagation through the cortical face network is altered in DP. The nature of the perceptual impairments in DP suggests that atypical visual experience with the eye region of faces over development may be an important contributing factor to DP.

Commonly associated face and object recognition impairments have implications for the cognitive architecture

“…This conclusion is consistent with the emerging view that face processing is often less functionally specialised in DPs than in the general population (e.g. Towler, Fisher, & Eimer, 2017). Because individuals with DP have impaired faceprocessing systems, they may rely more strongly upon more general visual recognition mechanisms, and as a result often share more variance between face and object recognition.…”

Normal composite face effects in developmental prosopagnosia

“…In typical observers, inverted faces reliably elicit larger N170 potentials than upright faces (Bentin, Allison, Puce, Perez, & McCarthy, 1996;Eimer, 2000;Rossion et al, 1999). A group of 16 DPs, however, showed no difference in their N170s to upright and inverted faces at the group level (Towler, Fisher, & Eimer, 2017;Towler et al, 2012). While the reason for the discrepancy between these findings is unclear, it appears that behavioural inversion effects and the N170 inversion effect are measuring different aspects of face processing.…”

The Montreal Protocol for Identification of Amusia

“…Researchers studying such disorders as dyslexia and specific language impairment (e.g., Aram, Morris, & Hall, 1993;Bishop & Snowling, 2004;Tomblin, Records, & Zhang, 1996), dyscalculia (e.g., Butterworth & Laurillard, 2010;Shalev, Auerbach, Manor, & Gross-Tsur, 2000), and prosopagnosia (e.g., Bowles et al, 2009; Duchaine & Nakayama, 2006;Towler, Fisher, & Eimer, 2017) face the same challenge. For these disorders, which all lack a single, unambiguous defining characteristic such as a specific genotype, individual performance must be categorized as Bimpaired^on the basis of continuous distributions of scores, meaning that the cutoff is largely arbitrary and is developed via consensus in the field (Towler et al, 2017). As was argued by Henry and McAuley (2010), one way to develop a more rigorous practice around the identification of these disorders will be to use multiple dependent measures and to compare patterns of performance to theoretically defined control versus disordered phenotypes.…”