The multiple-faces effect using fMRI: a tendency to reduced repetition priming for familiar faces presented at periphery.

Abstract

The multiple-faces effect (Perception, 2000, 29(11): 1393-1394) was first investigated at the blind spot using familiar faces. In this effect (where the face is presented peripherally) subjects may perceive changes in facial expressions, movement of face parts or other faces different from the one being shown. We studied this effect with event-related functional magnetic resonance imaging (fMRI) using blood oxygenation level-dependent (BOLD) contrast. Ten subjects (6 males and 4 females) participated in the experiment. We used two printed faces (i.e. 1 young male and 1 young female) configured to be presented either at the center, or at the right or left sides. We also presented a chair in the same configurations. All stimuli were shown binocularly and had a black dot indicating the fixation point. Each subject was presented with one of the faces and the chair in 12 experimental sessions where each of the six stimuli was repeated. Among other aspects, we tested the effect of repetition and face familiarity for observing the multiple-faces effect. Our preliminary on-going analysis of results shows that with very familiar faces both the fusiform and occipital areas are activated even after previous extensive exposure. This was true even for less familiar faces (i.e. peers, or unfamiliar). Considering these results, we intend to continue the study with new subjects using faces of the mother.

Footnotes

 Financial support: CNPq and FACEPE.