Emotional Rating of Pseudo-speech is Influenced by the Spatial Location of the Acoustic Source

IGNACIO SPIOUSAS; JORGE ARMONY

Montreal

Jornada; Douglas Research Day; 2017

Douglas Mental Health University Institute

Background: The rapid and accurate decoding of emotional expressions is crucial for social interactions and, in some cases, even for survival. Emotional information is often multimodal, typically relying on the visual and auditory systems. However, when such stimuli originate outside the individual?s visual field, only the acoustic information is present. It has therefore been hypothesized that in such cases the perceived emotional value of these stimuli should be enhanced. Methods: We investigate how the relative spatial location of a vocal expression (pseudo-speech prosody) affects its perceived emotional value. To this end, we employed a spherical array of loudspeakers (diameter 1.8m), housed in a semi-anechoic chamber, which allowed us to explore different source locations, including some above the horizontal plane (e.g. at the top of the head) and outside the visual field (e.g., behind the listener). Thirty-five healthy participants were asked to rate, using a continuous visual-analog scale, the perceived valence of a set of 30 pseudo-sentences, from five emotional categories (angry, fearful, happy, sad and neutral), arriving from nine different spatial locations. Results: Fearful expressions originating directly at the back were perceived as more negative, and angry expressions presented in the front