Silent speech of vowels in persons of different cognitive styles

Abstract

Introduction: This research measures the differences in silent speech of the vowels / a / - / u / in Spanish, in students with different cognitive styles in the Field Dependence – Independence (FDI) dimension. Method: Fifty-one (51) adults participated in the study. Electroencephalographic (EEG) signals were taken from 14 electrodes placed on the scalp in the language region located in the left hemisphere. Previously, the embedded figures test (EFT) was applied in order to classify them into dependent, intermediate and field independent persons. To analyse the EEG data, the signals were decomposed into intrinsic mode functions (IMF) and a mixed repeated measures analysis was performed. Results: It was found that the Power Spectral Density (PSD) in the vowels is independent of the cognitive style and its magnitude depends on the position of the electrodes. Conclusions: The results suggest that there are no significant differences in PSDs in the silent speech of vowels /a/-/u/ in persons of different cognitive styles. Significant differences were found in the PSDs according to the position of the 14 electrodes used. In our configuration, the silent speech of vowels can be studied using electrodes placed in premotor, motor and Wernicke areas.