Linda H. Lidborg¹, Anna Yue Gao¹, A. Mike Burton^2,3, Holger Wiese¹; ¹Durham University, ²University of York, ³Bond University

Previous research has suggested that attentional capacity limits permit the processing of just one face at a time. However, we have previously shown that the brain is capable of processing two different facial identities, if faces are simultaneously presented in equally relevant spatial locations. Here, we used event-related potentials (ERP) and immediate repetition priming to test whether two facial identities are still processed simultaneously when one face is made more relevant than the other. In Experiment 1, stimuli consisted of both famous and unfamiliar faces. Two facial primes were presented simultaneously: one prime appeared in a central location in every trial, while an additional, peripheral prime unpredictably appeared to the left or to the right of the central prime. Here, we observed an ERP priming effect with more negative amplitudes at occipito-temporal electrodes for central but not peripheral familiar faces from 300 ms onwards. Similarly, an unfamiliar central prime also did not allow for the processing of a peripheral familiar prime. In Experiment 2, primes consisted of faces or written names of familiar celebrities. The prime locations were identical to Experiment 1; however, while the peripheral prime was always a face, the central prime could be either a face or a name. Here, we observed ERP priming effects for peripheral faces when the central prime showed a name, but not when the central prime showed a face. Together, these results suggest that while it is possible for the brain to process peripheral (less relevant) faces, this only occurs if the central stimulus is not also a face; a centrally presented face captures domain-sensitive attentional resources independent of familiarity and blocks the processing of an additional face.

Acknowledgements: Funded by Economic and Social Research Council (ESRC, UK) grant ES/X014657/1 to HW and AMB.