Abstract
There are large individual differences in perceiving, learning, and recognizing faces swiftly and accurately that have never been systematically investigated. By studying individual differences in 209 participants in a broad variety of indicators, we distinguished three component abilities of face cognition: face perception, face memory, and the speed of face cognition. Our results showed that these component abilities are also distinguishable from such traditional mental abilities as object cognition, general cognitive ability, mental speed, and general memory. We used event-related brain potentials (ERPs) to examine the neural basis of the component abilities in face cognition and to see how individual differences are reflected in relevant ERPs. For this purpose, the N170, the difference due to memory, the early and late repetition effects, and the old/new effect were measured in 85 participants of the original sample. Because the ERPs showed high psychometric quality (that is, internal consistency and unidimensionality), we could use structural equation modeling to investigate the relationships of these ERPs to the three component abilities of face cognition. The latent factors of repetition effects, of old/new effect, and of N170 latency correlated moderately with the component abilities. Individuals with faster structural encoding, as measured with N170, performed better in face perception, but not face memory or speed of face cognition. Individuals with earlier and higher brain activation during face recognition, as measured with priming and old/new effects, performed better in face perception and face memory only. Individuals with higher pre-activation of memory representations, as measured with the early repetition effect, processed faces faster. Our research thus shows that structural equation models can be used both to study individual differences in ERPs, and to clarify the relationships of the processes indicated by specific ERPs.
This research was supported by a grant from the State of Berlin (NaFöG) to G. H. and by a grant from the Deutsche Forschungs-gemeinschaft (Wi 2667/2-2) to O. W. and W. S.