Individual differences in face processing

Human ability to recognize identities from faces is a fundamental cognitive skill that underlies our functioning in the social world. This ability varies widely in the general population, with the ends of the spectrum of abilities characterized by ‘atypical’ populations (people with developmental prosopagnosia, autism, and super recognition). Different theoretical models have been suggested to explain this variability, suggesting atypical visual perception (e.g., scanning patterns) or information integration (e.g., holistic processing). However, experimental evidence for these theories has been mixed, with most models inadequately accounting for individual differences. This thesis seeks to improve our approach to measuring face perception to advance our understanding of face recognition subprocesses.
Chapter 1 reviews the current conceptualization of atypical groups and outlines the theoretical framework for my research. Key hypotheses and mechanisms are outlined to improve measurement of identity processing across abilities. In particular, I focus on tests of face perception and memory and their shortcomings in the context of measuring individual differences, and outlined a novel way of developing face processing tests relying on facial recognition algorithms.
Chapter 2 outlined the process of developing and validating a novel measure of face perception, the Oxford Face Matching Test (OFMT). It revealed that the novel measure captures a wide range of performance in typical groups and is stable over time. Chapter 3 explored how the OFMT can be utilized in person and online to measure face recognition processes in a large sample of diverse neurotypical participants. Results confirmed the hypothesized contributions of face perception and face matching to face memory.
Chapters 4, 5, and 6 explored whether administration of the OFMT gives sufficiently sensitive scores at the ends of the spectrum in large groups of developmental prosopagnosics (Chapter 4), super recognisers (Chapter 5) and people with autism (Chapter 6). These chapter investigated the relationship between independently measured subprocesses necessary for successful face recognition. Findings suggested different patterns of atypicality, with super recognizers showing superior performance on all subprocesses, and people with autism and developmental prosopagnosia showing different patterns of impairments with face perception, matching and memory.
Chapter 7 looked at ageing-related changes to face perception and memory abilities in a large sample of healthy participants across a range of ages. Results revealed effects of ageing on face matching tests, but importantly no ageing-related effects on face memory when face perception was measured precisely using the more sensitive OFMT.
In Chapter 8, I discuss the implications of this body of work for updating theoretical models of face recognition and applying novel methods to the development of future face processing measures, as well as their application in real-life scenarios of training and automation of security processes. This body of work overhauls the methodological approach to measuring individual differences in face perception and offers a novel approach to independently capturing subprocesses necessary for face recognition. These methods hold promise for answering long-standing questions of the relationships between these subprocesses and the resulting explanatory mechanisms of atypical perception.

Advisor: Bird, G