Event-related potentials in the implicit recognition of faces / 中华物理医学与康复杂志

ABSTRACT

Objective To use event-related potentials to identify whether face recognition is implicit, and to investigate specificity, race and inversion effects in face recognition. Methods Upright and inverted photographs of Eastern and Western human faces, upright dog faces and a mobile phone were presented in random order for 150 ms to 20 healthy subjects. The subject's attention was diverted away to search for the letter ”f ” in 6 small letters below the photos. Behavioral data were recorded synchronous with event-related potentials (ERPs). Results The P100,N170 and P170 potentials were enhanced and accelerated by faces compared with non-face images. The amplitude of P100 had the strongest correlation with the type of stimulus, showing the biggest amplitude with the mobile phone image (9.5 μV ), followed by the dog face (7.5 μV ). The weakest amplitude was evoked by the human face (6.9 μV). The amplitude of N170 responded most strongly to the human face, followed by the mobile phone (0.5 μV) and the dog face ( -1.9 μV). The P170 amplitude was largest with the human face and the latency was shortest (7.8 μV and 162.2 ms), followed by the dog face (5.2 μV, 174.4 ms) and the mobile phone (5.1 μV,173.5 ms). ERP components were not affected by the orientations or races of the faces in this situation. No difference was found in the late positive component evoked by the human faces and other images. Conclusions Implicit face recognition may depend on the specifics of the stimulus, although no race effect or inversion effect was detected using this procedure.