What is the prevalence of developmental prosopagnosia? An empirical assessment of different diagnostic cutoffs

Autistic adults have insight into their relative face recognition ability

“…Many autistic individuals with severe co-occurring prosopagnosia may fail to meet diagnostic thresholds simply because of measurement error. Second, the severity of developmental prosopagnosia is thought to vary 53 . While some autistic individuals may experience severe developmental prosopagnosia, others may experience relatively mild forms.…”

Balanced Integration Score: A new way of classifying Developmental Prosopagnosia

“…These could be due to genuine heterogeneity, perhaps accentuated by the small sample sizes typical in neuropsychology. However, it is possible that the competing findings may, in part, also be explained by the varied approaches taken by different research groups to classifying DP (Bate & Tree, 2017) and by the range of different tests and measures used for classification and assessment of face processing in DP (for an overview see DeGutis et al, 2023;Robotham & Starrfelt, 2018). Broadly, the literature shows that approaches to categorisation differ across studies in three main, yet inter-related, ways.…”

“…How researchers choose to define study inclusion and exclusion for the DP and control groups has important implications for our ability to fully understand DP. A key question is why so many individuals who report severe problems recognising familiar faces in everyday life do not appear to meet the classification for DP (for a discussion see Burns et al, 2022;DeGutis et al, 2023)? For example, a recent large-scale study of 165 adults who reported severe everyday face recognition problems (Bate et al, 2019) showed that 61.8% of the 165 suspected DPs did not meet the commonly used diagnostic threshold of at least 2 SDs below control means on a minimum of two of the three commonly-used diagnostic tests.…”

“…The studies by Bate and colleagues (2019) and Burns et al, (2022) are relatively unusual in assessing the performance of all the self-reported DPs. More commonly in the literature only those participants who meet strict objective criteria for DP are included in studies (for a review see DeGutis et al, 2023). Unnecessary exclusion of a high proportion of potential participants who report this rare condition is problematic, both for practical and, arguably, ethical reasons (Burns et al, 2022).…”

“…Increasingly therefore, several research groups have begun to question whether the current approaches to classifying DP are appropriate and suggest that broader inclusion criteria might help inform our understanding of DP (Berger et al, 2022;Burns et al, 2022;Dalrymple & Palermo, 2016;DeGutis et al, 2023;Mishra et al, 2021;Stumps et al, 2020). Unless future research includes both the full range of individuals who report FR problems (potential DPs) and the full range of neurotypical individuals who score poorly on face processing tasks but do NOT report FR problems on the PI20 or similar questionnaire, we are unlikely to be able to satisfactorily characterise DP.…”