Meyer
Fakultäten » Philosophische Fakultät » Psychologisches Institut » Neuropsychologie » Prof. Dr. Lutz Jäncke » Meyer
Current research project
| Title / Titel | Structural and functional mapping of local and global speech perception in the human auditory system | ||
|---|---|---|---|
| Abstract (PDF, 14 KB) | |||
| Summary / Zusammenfassung | This project will focus on functional brain mapping of global and local acoustic feature processing in the context of speech perception. In the recent past our understanding of brain mechanisms underlying speech perception has dramatically changed from a domain-centered view that looks for neural substrates of linguistics domains (e.g. syntax, semantics) to a parameter-based approach. The latter proposals provide the theoretical basis for the empirical research this project is based upon. It primarily seeks to describe how the human auditory system processes elemental acoustic cues that constitute the foundation of speech. According to the parameter-based models, the left auditory system is preferentially driven by rapidly changing local auditory cues (i.e. formant transitions, voice-onset time) while the right auditory cortex appears to be particularly susceptible to slowly changing global acoustic modulations (i.e. sentence intonation, duration, rhythm in propositional speech. The first leg of the planned project will continue the research on local and global auditory perception at the prelexical level (temporal envelopes, consonants, vowels, CV syllables) but will also extend former research on propositional speech perception of proper and manipulated sentences. In a series of fMRI experiments and EEG studies in combination with a source estimation approach we will systematically test the sensitivity of human auditory regions to speech and nonspeech sounds whose core acoustic features (intonation, temporal integrity, spectral complexity) have been systematically manipulated to learn more about the functional lateralization of specialized neural circuits in the auditory region. The fMRI part will test specific predictions with respect to functional lateralization. The EEG part will put emphasis on the spatiotemporal pattern of early speech and nonspeech perception and elucidate the comparability of hemodynamic and electrophysiological data. The two parts will include carefully designed behavioral studies that seek to identify an experimental paradigm delivering an optimal balance of processing performance of speech and nonspeech sounds. Functional data will be mapped onto structural templates with utmost accuracy. For this purpose, we will use cyto- and receptorarchitectonically based probability maps of peri-auditory regions that are under current development at the Institute of Medicine of the Research Centre Julich (Prof. Katrin Amunts). The application of these maps will help interpret the functional responses without the pitfalls of standard mapping procedures. The major focus of this branch of the project will be on structural differences in lateralization which will be carefully observed and interpreted with respect to the functional lateralization data the proposed project will provide. A complete morphometric delineation of peri-auditory regions does presently not exist and is supposed to be considered an invaluable complement to the loose collective of structural macroscopic measurements that have been provided by distributed groups during the last 15 years so far. |
||
| Keywords / Suchbegriffe | brain imaging, speech perception | ||
| Project leadership and contacts / Projektleitung und Kontakte |
|
||
| Funding source(s) / Unterstützt durch |
SNF (Personen- und Projektförderung) |
||
| Duration of Project / Projektdauer | Apr 2009 to Mar 2012 |