Features of Internal Pronunciation of Words by a Group of People with Rhotacism in Comparison with Normative Pronunciation

Existing studies in the field of speech disorders do not provide a systematic understanding of the relationship between the bioelectrical activity of the brain and the nature of speech disorders, the characteristics of the processes of speech perception and internal pronunciation. This work is aimed at comparing the activity of the brain during the internal pronunciation of words by a group of people without speech disorders and a group of people with rhotacism. For the first time, an analysis and comparison of event-related potentials (ERP) of the brain in the process of internal pronunciation in people with and without rhotacism was carried out. The electroencephalographic (EEG) study involved 36 people, 18 of them had a speech disorder in the form of rhotacism. The subjects were presented with auditory stimuli (words) spoken by a speaker with standard sound pronunciation. The subject’s task was to mentally repeat the word, maintaining the intonation and pronunciation features, as in external speech. The results obtained in this study using a new method of localization of brain activity demonstrate significant differences in ERP during the mental pronunciation of words between the studied groups of people in a number of brain structures, including cortical and subcortical formations. The group of people with rhotacism is characterized by the presence of a pronounced ERP N200 in more evolutionarily early brain structures, such as the midbrain, medulla oblongata and insular lobe on the left. The group of people without speech disorders is characterized by the presence of pronounced ERP in the following structures: caudate nuclei on the right and left, right globus pallidus, cingulate cortex, striatum, dorsomedial prefrontal cortex, anterior cingulate cortex, field 17 on the right and left, Broca’s area on the right, Wernicke’s area on the right, angular gyrus on the right, anterior prefrontal cortex on the right and left. All differences are obtained with an estimate of 95% confidence interval.