The multiple-faces effect was first investigated at the blind spot using familiar faces. We analyzed the effect into 4 categories: 1) disappearance/darkening/whitening of face parts; 2) variation in size of face parts; 3) perception of movement /change in facial expression; 4) perception of other faces. Categories 1 and 2 reflect initial impressions. Only reports falling into categories 3 and/or 4 show the multiple-faces effect. Results analyzed data from 37 subjects (using mother and/or father and/or other relatives' photographs). Analysis across subjects yielded 87% and 68% in categories 3 and 4, respectively. In category 3, changes in facial expression were 90% and 82% for mother and father faces, respectively. In category 4, other faces were more frequently observed with the mother's face (73%) than the father's (41%) face. We discuss these results in terms of peripheral processing of form considering a possible tuning for faces resulting from frequency of viewing the same face during early visual development.
Visual adaptation; face adaptation; face perception; multiple-faces effect; spatial frequency
