The emotional component of inner speech: A pilot exploratory fMRI study

Abstract

Inner speech is one of the most important human cognitive processes. Nevertheless, until now, many aspects of inner speech, particularly the emotional characteristics of inner speech, remain poorly understood. The main objectives of our study are to identify the neural substrate for the emotional (prosodic) dimension of inner speech and brain structures that control the suppression of expression in inner speech. To achieve these goals, a pilot exploratory fMRI study was carried out on 33 people. The subjects listened to pre-recorded phrases or individual words pronounced with different emotional connotations, after which they were internally spoken with the same emotion or with suppression of expression (neutral). The results show that there is an emotional component in inner speech, which is encoded by similar structures as in spoken speech. The unique role of the caudate nuclei in the suppression of expression in the inner speech was also shown.