EEG-Project: Sentence Production

P 13748-SPR (Grant for 2000 and 2001. Research project)
Principal applicant: Univ.Prof. Dr. Hubert Haider

Sentence production: EEG-oscillations during sentence processing.

(Project team: Univ.Prof. Dr.Hubert Haider, Univ.Prof. Dr.Wolfgang Klimesch, Mag. Dietmar Röhm)

The project investigated the following question: Is it possible to identify domain specific cognitive processing components in the EEG-spektrum? The specific cognitive domain is language, in particular, sentence production.

The declared aim of the project was the identification relevant EEG-correlates of basic language processing activities by means of spectral- and frequency-analytical methods. These methods investigate the EEG-records for correlates of specific processing activities in specific frequency bands. We hoped to detect different frequency-specific activities for syntactic processes and for lexical search and retrieval processes.

The experiments were designed to isolate two basically different language specific processes: a purely syntactic process of structure generation and a lexical-semantic process (retrieval of a semantically identified expression). The applied method concentrates on the investigation of band power changes, measured during the execution of the experimentally triggered language processes.

An essential goal of the experiments was to show that this novel approach can be applied fruitfully to the inquiry of language processing activities (as specialized cognitive processes). In particular, we expected different but frequency specific oscillations to show up according to the processing task which subsequently can be filtered from the total spectral activity and assigned to the respective task-specific portions.

This basic aspect of the chosen paradigm could be strikingly validated in the experiments carried out. The experiments did not only reproduce the by now well known unspecific band power changes (general attention- and expectancy effects, working memory demands), but proved also successful with respect to the hypothesized specific band power changes.

The main results are: Specifically linguistic cognitive processing activi­ties do have correlates in the oscillation patterns. On the one hand, the upper alpha desyn­chroni­zation (10-12 Hz.) correlates with semantic processing. On the other hand, semantic processing does not draw on general working memory capacities (no theta-band specific synchroni­za­tions). These results pave the way for further investigations in this area.

Project publications:

Röhm, D., Klimesch, W., Haider, H. & Doppelmayr, M. (2001). The role of theta and alpha oscillations for language comprehension in the human electroencephalogramm. Neuroscience Letters, 310, 137-140.

Röhm, D., Haider, H. & Klimesch, W. (2001). EEG-oscillations during sentence processing (Abstract) In: T. Arnold & C. S. Herrmann (eds.), Cognitive Systems & Mechanisms. Leipzig: Leipziger Univ.-Verl., p. 108.

Röhm, D., Haider, H. & Klimesch, W. (2004). Gehirnoszillationen und Sprache: EEG-Bandpowerveränderungen bei Sprachverarbeitungsprozessen. In: Horst M. Müller & Gert Rickheit (Hrsg.) Neurokognition der Sprache. Tübingen: Stauffenburg Verlag. 259-286. (submitted 2002)