Colour is irrelevant for familiar face recognition: Evidence from event-related brain potentials

Familiar face recognition is based on image-invariant representations of known faces which can be activated from highly variable instances. While the existence of such representations is well-established, it is less clear what specific information is stored in them. Here, we examined whether colour, and more specifically hue and saturation, is beneficial for activating familiar face representations. In a series of three experiments, we used event-related brain potentials (ERPs) in an immediate repetition priming paradigm. In all three experiments, we observed clear ERP priming effects, with more negative amplitudes at occipito-temporal channels when identity was repeated between prime and target, relative to the non-repetition conditions, starting approximately 220 msec after target onset. In Experiment 1, these ERP repetition effects were highly similar for colour and greyscale primes. This finding was replicated in Experiment 2, which used spatially low-pass filtered primes to reduce high spatial frequency identity cues. Finally, prime faces in Experiment 3 were presented with reversed hue and saturation values. Again, ERP repetition effects were highly similar as compared to naturally coloured faces. These findings suggest that colour information is not beneficial, and indeed largely irrelevant for facial identity processing. We therefore conclude that familiar face representations do not contain identity-specific colour information.