Zerebrale Kontrolle motorischer Aspekte der Sprachproduktion

• Applicants: Professor Dr. Hermann Ackermann; Professor Dr. Grzegorz Dogil (†); Professor Dr. Wolfram Ziegler
• Subject Area: Human Cognitive and Systems Neuroscience
• Term: from 2004 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5430626

The neuroanatomical substrates of the interface between cognitive-linguistic operations and speech motor output are still poorly understood. This challenge provided the basis for a series of functional magnetic resonance imaging (fMRI) studies of our research groups. First, interactions of left-sided premotor cortex and contralateral cerebellar hemisphere were found to subserve inner speech of highly overlearned word strings. Second, participation of the cerebellum in this process seems to be bound to syllable sequences above a rate of 3 Hz. Considering recent psycholinguistic models of speech production as well as preceding investigations of our groups on speech timing in ataxic dysarthria, we assume this observed network to reflect cerebellar concatenation of retrieved mental syllables from a left-hemisphere premotor store at a speaker's habitual speech tempo of 4 to 6 Hz. Thirdly, activation of the anterior insula was found associated with overt speech. The proposed project focuses on an experimental evaluation of the mentalsyllabary component of this model, and its interactions with cerebellum and anterior insula. The data corpus generated at IMS Stuttgart will provide the test materials both for the planned phonetic investigations of speech by normals, the clinical investigations at the EKN-Clinical Neuropsychology Research Group, City Hospital Munich-Bogenhausen, as well as the fMRI studies in normal subjects at the University of Tübingen. Finally, the IMS will develop and implement a computational model which will concentrate on temporal/prosodic organization of speech and its neural control and explicitly specify the retrieval process during phonetic encoding, including retrieval from the exemplar-based syllabary.

• DFG Programme: Research Grants
• Participating Persons: Professor Dr. Wolfgang Grodd; Professor Dr. Axel Riecker