The domain-specificity of face matching impairments in 40 cases of developmental prosopagnosia

Abstract

A prevailing debate in the psychological literature concerns the domain-specificity of the face recognition system, where evidence from typical and neurological participants has been interpreted as evidence that faces are "special". Although several studies have investigated the same question in cases of developmental prosopagnosia, the vast majority of this evidence has recently been discounted due to methodological concerns. This leaves an uncomfortable void in the literature, restricting our understanding of the typical and atypical development of the face recognition system. The current study addressed this issue in 40 individuals with developmental prosopagnosia, completing a sequential same/different face and biological (hands) and non-biological (houses) object matching task, with upright and inverted conditions. Findings support domain-specific accounts of face-processing for both hands and houses: while significant correlations emerged between all the object categories, no condition correlated with performance in the upright faces condition. Further, a categorical analysis demonstrated that, when face matching was impaired, object matching skills were classically dissociated in six out of 15 individuals (four for both categories). These findings provide evidence about domain-specificity in developmental disorders of face recognition, and present a theoretically-driven means of partitioning developmental prosopagnosia

Diagnosing developmental prosopagnosia: repeat assessment using the Cambridge Face Memory Test

“…This hypothesis is supported by our analyses that directly addressed the domain-specificity of the face recognition difficulties reported by our population-a question that has received much attention in very recent years [16,79,80]. In the current study, two of the 15 laboratory participants who completed the CFMT1 and the CCMT were impaired on both tests, as were two of the 12 online participants who completed these tasks.…”

“…Currently, most researchers diagnose the condition using a combination of the Cambridge Face Memory Test (CFMT: [ 14 ]), the Cambridge Face Perception Test (CFPT: [ 15 ]) and a famous faces test (e.g. [ 16 – 18 ]). Dominant recommendations suggest that DP is diagnosed when scores fall into the impaired range (typically at least two s.d.…”

“…The test substantially improves hit rates for diagnosing DP in comparison to other well-known face recognition tests [ 2 , 14 , 39 ], and shows a substantial inversion effect [ 15 , 40 ]. Correlation studies demonstrate the independence of CFMT performance from other cognitive abilities such as IQ [ 41 , 42 ], object recognition [ 16 , 43 ], verbal memory [ 38 ] and global attention [ 42 ]. However, the test–retest reliability of the CFMT has not yet been investigated, and it is currently unknown whether practice effects occur on repeat administration of the task.…”

Normal colour perception in developmental prosopagnosia

“…This finding indicates that, in the case of colour perception, DP does not appear to be heterogenous. Our finding aligns with the theoretical view that DP is a domain-specific disorder of face processing 29 , 63 , and that non-face deficits in DP likely result from independent impairments that may co-vary with DP. Our finding also puts a constraint on more generalist theories that seek to explain DP in terms of broader visual impairments beyond face processing 22 , by requiring those domain-general models to account for normal colour perception.…”

“…Our study provides strong evidence that helps clarify the extent of broader visual deficits in DP. Research into this issue has mainly focused on testing visual recognition of non-face objects 24 , 25 , 28 , 63 – 66 , but a growing number of studies has started to assess a broader range of visual functions including biological motion 10 , 67 , navigation 30 , 31 , 68 , word processing 69 , and colour vision 43 . These studies tend to find mixed results 22 , 23 , likely due their small sample sizes and the potentially heterogenous nature of DP.…”