In humans, information about the face is very important for first impression formation and establishing interpersonal relationships. We investigated the effect of anticipation of an ongoing connection with others on brain activity and neutral face recognition using functional magnetic resonance imaging (fMRI).

Sixteen young, right-handed females participated in this study (mean age±standard deviation: 21.7±3.2 years, range 20–34 years). They were healthy undergraduate or graduate students with no history of significant medical, psychiatric, or neurological disorders. All gave written informed consent to participate, and Tokyo Metropolitan University Research Ethics Committee (No. 17048) approved the study. During fMRI scanning, subjects were shown photographs of people with neutral facial expressions (72 neutral photographs from the face database that made by the university of FEI). Subjects were asked to consider each photograph under the following conditions: Condition 1, “I will meet the person in this photo only once.”; Condition 2, “I will meet the person in this photo multiple times.” Each photo was presented for 8 s. The total fMRI duration was 408 s. All functional imaging data were preprocessed and analyzed using SPM8 implemented in MATLAB (significance set at an uncorrected P<0.001). We estimated brain activity differences between the 2 conditions.

The left caudate nucleus was significantly activated in Condition 2 compared with Condition 1. The right substantia nigra had a significantly different blood-oxygen-level dependent response in Condition 1 compared with Condition 2.

The anticipation of an ongoing connection could affect the first impression formation process in the human brain.