EEG correlates of inner speech

Abstract: The aim of this bachelor thesis was to study EEG correlates of inner speech. In particular, I want to know if it is possible to distinguish different semantic categories when the subjects speak the words with an inner voice. It would be a great opportunity for brain-computer- interfaces (BCI) if the computer could decode from the EEG-recordings what the patient wishes, be it food or the realisation of an action directly from the specific thought and not through surrogate thoughts. Many recent studies showed with neuroimaging technics that different semantic classes induce activations in different cortical areas. A word does not only have a semantic meaning but also evokes related associations, which are processed in dif- ferent cortical regions. As different categories have different associations, various brain re- gions are activated. Besides, these differences in EEG-correlates between semantic classes have not yet been described for inner speech. Ten subjects repeated 112 words from the categories ‘animals’, ‘food’, ‘tools’ and ‘pseudowords’ for three seconds in their minds. ‘Tools’ is expected to induce stronger activation over the motor cortex, ‘animals’ is expected to in- duce more activation over the visual cortex and ‘food’ in cortical regions related to gustatory or olfactory associations. ‘Pseudowords’ are used as second baseline to detect activation in brain areas in addition to the language system. The other baseline was a neutral condition before the stimulus occurred. Unfortunately, there are no differences between the semantic categories. All visible effects appear in all semantic classes and were evoked by the visual stimulus or the working memory. Possible reasons for this result are discussed and im- provements for the experimental design are proposed

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Albert-Ludwigs-Universität Freiburg, Bachelorarbeit, 2015

Classification and Topics

• Keyword: Elektroencephalographie ; Gehirn ; Zentralnervensystem

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2018
• Creator: Rau, Veronika ; Fiederer, Lukas D. J. ; Ball, Tonio
• Contributor: Freiburg Brain Imaging ; Albert-Ludwigs-Universität Freiburg. Fakultät für Biologie ; Albert-Ludwigs-Universität Freiburg

Further information

• DOI: 10.6094/UNIFR/15003
• URN: urn:nbn:de:bsz:25-freidok-150033
• Rights: Kein Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 25.03.2025, 1:56 PM CET