Inner Speech in Portuguese: Acquisition Methods, Database and First Results

In this paper, we present a database developed for studying inner speech brain related areas using functional Magnetic Resonance Imaging (fMRI) in the context of the European Portuguese. First, we addressed the type of stimuli used in inner speech studies. In this sense, considering a preliminary study using a picture naming task, we defined a corpus. The corpus was designed based on cardinal vowels, syllable, disyllabic words and sentences with structure S(ubject)V(erb)O(bject) which were balanced in syllable number (six to ten). All the words used are common words from the Portuguese lexicon and possible ambiguities were excluded. Currently, the dataset includes data from twenty healthy participants native Portuguese speakers. Preliminary, exploratory analysis on the data allowed us to identify the most relevant areas part of the inner speech network, that include inferior frontal gyrus (including Broca’s area), supplementary motor area and precentral gyrus. Ultimately, the better understanding of the inner speech mechanisms will pave way to the development of novel intervention strategies in linguistic disorders.