Eye-Movement Strategies in Developmental Prosopagnosia and “Super” Face Recognition

Abstract

Developmental prosopagnosia (DP) is a cognitive condition characterised by a severe deficit in face recognition. Few investigations have examined whether impairments at the early stages of processing may underpin the condition, and it is also unknown whether DP is simply the "bottom end" of the typical face-processing spectrum. To address these issues, we monitored the eye-movements of DPs, typical perceivers and "super recognizers" (SRs) while they viewed a set of static images displaying people engaged in naturalistic social scenarios.Three key findings emerged: (1) individuals with more severe prosopagnosia spent less time examining the internal facial region, (2) as observed in acquired prosopagnosia, some DPs spent less time examining the eyes and more time examining the mouth than controls, and (3) SRs spent more time examining the nose -a measure that also correlated with face recognition ability in controls. These findings support previous suggestions that DP is a heterogeneous condition, but suggest that at least the most severe cases represent a group of individuals that qualitatively differ from the typical population. While SRs seem to merely be those at the "top end" of normal, this work identifies the nose as a critical region for successful face recognition.Keywords: prosopagnosia, super recognizers, face recognition, eye movements, individual differences. Eye Movements and Face Recognition 3Eye-Movement Strategies in Developmental Prosopagnosia and "Super" Face Recognition Prosopagnosia is a neuropsychological disorder characterized by a failure to recognize familiar faces. While some individuals acquire the condition following neurological trauma (e.g. Damasio, Damasio, & Von Hoesen, 1982), it is thought that approximately two per cent of the population have developmental prosopagnosia (DP: Bennetts, Murray, Boyce, & Bate, under review for this review; Bowles et al., 2009). This form of the disorder has been attributed to a failure to develop the visual recognition mechanisms necessary for successful face recognition, despite intact low-level visual and intellectual functions (Susilo & Duchaine, 2013). Interestingly, there also appears to be a genetic component to the condition in at least some individuals (Duchaine, Germine, & Nakayama, 2007; Grueter et al., 2007).Due to considerable difficulties hindering early diagnosis of face recognition difficulties, it is essentially impossible to distinguish the former, developmental, from the latter, congenital, form of prosopagnosia. For the purpose of this paper we are thus referring to all types of prosopagnosia unrelated to known neurological trauma and without concomitant disorders known to affect face processing as "developmental".A multitude of work with both healthy and impaired participants has contributed to cognitive neuropsychological theories of face recognition, such that it is generally accepted that the process consists of a series of sequential stages that can selectively be damaged by neurological trauma (e.g. Bruce & Young, ...

Reduced sensitivity to contrast signals from the eye region in developmental prosopagnosia

“…If there is a general tendency for DPs not to fixate on the eye region but on the lower part of faces (e.g. Bobak, Parris, Gregory, Bennetts, & Bate, 2016;Schwarzer et al, 2007), this might result in the development of an increased perceptual sensitivity to contrast signals from the upper visual field region that contains the eyes. In this context it is worth noting that typical N170 amplitude enhancements to deviations in contrast polarity from canonical face templates progressively emerge throughout childhood and into early adulthood (e.g., Itier & Taylor, 2004a).…”

The Kent Face Matching Test

“…However, these three tests are unified on the basis that all focus on the identity processing of unfamiliar faces. The CFMT and CFPT have been used widely and are typically employed to assess impairments in face processing (see, e.g., Bobak, Parris, Gregory, Bennetts, & Bate, 2017;Ulrich et al, 2017;White et al, 2017), as well as superior recognition ability (Bobak, Hancock, & Bate, 2016;Bobak, Parris, et al, 2017;Russell, Duchaine, & Nakayama, 2009). Thus, the CFMT and CFPT provide suitable tests against which performance in the KFMT can be compared.…”

Robust associations between the 20-item prosopagnosia index and the Cambridge Face Memory Test in the general population

“…Many authors also report performance on famous face recognition tests (e.g. [7,15,16]). In addition to scores on computer-based tests, however, self-report measures provide a complementary source of diagnostic evidence.…”