Event-related potentials reveal the development of stable face representations from natural variability

ABSTRACT

Natural variability between instances of unfamiliar faces can make it difficult to reconcile two images as the same person. Yet for familiar faces, effortless recognition occurs even with considerable variability between images. To explore how stable face representations develop, we employed incidental learning in the form of a face sorting task. In each trial, multiple images of two facial identities were sorted into two corresponding piles. Following the sort, participants showed evidence of having learnt the faces performing more accurately on a matching task with seen than with unseen identities. Furthermore, ventral temporal event-related potentials were more negative in the N250 time range for previously seen than for previously unseen identities. These effects appear to demonstrate some degree of abstraction, rather than simple picture learning, as the neurophysiological and behavioural effects were observed with novel images of the previously seen identities. The results provide evidence of the development of facial representations, allowing a window onto natural mechanisms of face learning.

KEYWORDS:

• Event-related potentials
• Face learning
• Face recognition
• N250
• Stable representations

Acknowledgments

We are grateful to Kathrin Rauscher and Carolin S. Altmann for their help during EEG recordings.

Notes

1. Please note that a corresponding ANOVA, in which two participants with error rates of more than 2 standard deviations above the mean in the sorting task were excluded, yielded highly similar results. A significant main effect of exposure, F(1, 21) = 14.51, p < .001,  = .409, was related to more negative amplitudes for seen-in-sort-sIMG, seen-in-sort-dIMG, and famous relative to new-to-ERP IDs [all F(1, 21) > 13.26, all p < .002, all  > .387]. Famous trials were more negative than both seen-in-sort-sIMG and seen-in-sort-dIMG trials [both F(1, 21) > 6.24, both p < .021, both  = .229], and there was no difference between seen-in-sort-sIMG and seen-in-sort-dIMG trials, F(1, 21) = 0.98, p = .332,  = .045.

Additional information

Funding

The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (FP/2007–2013)/ERC [grant agreement no. 323262]; and from the Economic and Social Research Council, UK [grant number ES/J022950/1]; and an Experimental Psychology Society (EPS) study visit grant.