Abstract
People are generally better at recognizing faces from their own race than from a different race. The so-called other-race effect has been examined in numerous behavioral studies, but its underlying neural processes have been less extensively researched. This study investigated how differences between own-race and other-race faces influence memory encoding and recognition memory. Event-related potentials (ERPs) of Asian and Caucasian participants were recorded during the study and test phases of a Remember-Know paradigm with Asian and Caucasian faces. The other-race effect was apparent in both groups, neither of which recognized other-race faces as well as own-race faces; but Caucasian subjects showed stronger other-race effects in memory performance. Using ERPs, we independently investigated the influence of stimulus race on two time points of memory: encoding and recollection. In the study phase, memory encoding was measured with mean amplitudes and the ERP difference due to memory (Dm). Correctly “recollected,” own-race faces elicited lower mean amplitudes and were thus more efficiently encoded into memory than correctly “recollected” other-race faces. Dms for subsequent recollection and familiarity were indistinguishable only for own-race faces, which suggest that more elaborate memory encoding occurred for own-race than other-race faces. Experience with a race also influenced old/new effects, ERP correlates of recollection measured during recognition testing, but only for Caucasian subjects. Own-race faces elicited a typical parietal old/new effect, whereas old/new effects for other-race faces were dominated by activity in frontal brain regions, suggesting a stronger involvement of cognitive control processes. The temporal dynamics of memory retrieval were also influenced by the race of a face. Whereas recognition of other-race faces was prolonged until at least 1200 ms and required post-retrieval monitoring, recollection of own-race faces was completed after about 900 ms. These results indicate that the other-race effect is a memory encoding- and recognition-based phenomenon.
This research was funded by NSF grant #SBE-0542013 to the Temporal Dynamics of Learning Center (an NSF Science of Learning Center), NIH Grant MH64812, and a James S. McDonnell Foundation grant to the Perceptual Expertise Network.