Table of Contents
International Journal of Brain Science
Volume 2015 (2015), Article ID 719213, 7 pages
http://dx.doi.org/10.1155/2015/719213
Research Article

Effects of Facial Expression and Language on Trustworthiness and Brain Activities

1Neurorehabilitation Research Center, Kio University, Nara, Japan
2Department of Rehabilitation, Kitade Hospital, Wakayama, Japan

Received 23 January 2015; Revised 22 May 2015; Accepted 24 May 2015

Academic Editor: Martin Herrmann

Copyright © 2015 Shu Morioka et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Social communication uses verbal and nonverbal language. We examined the degree of trust and brain activity when verbal and facial expressions are incongruent. Fourteen healthy volunteers viewed photographs of 8 people with pleasant (smile) or unpleasant expressions (disgust) alone or combined with a verbal [positive/negative] expression. As an index for degree of trust, subjects were asked to offer a donation when told that the person in the photograph was troubled financially. Positive emotions and degree of trust were evaluated using the Visual Analogue Scale (VAS). Event-related potentials (ERPs) were obtained at 170–240 ms after viewing the photographs. Brain activity during incongruent conditions was localized using standardized Low Resolution Brain Electromagnetic Tomography (sLORETA). VAS scores for positive smile condition were significantly higher than those for the other conditions (). The donation offered was significantly lower for incongruence between verbal and facial expressions, particularly for negative smile condition. EEG showed more activity in the parietal lobe with incongruent than with congruent conditions. Incongruence [negative smile] elicited the least positive emotion, degree of trust, and amount of offer. Our results indicate that incongruent sensory information increased activity in the parietal lobe, which may be a basis of mentalizing.