Hillel Pratt, PhD
Professor of Medicine and Biomedical Engineering
PhD, 1978 - Hebrew University, Israel
Characterization of neural networks for processing speech and non-speech sounds in the human brain: electrophysiological functional imaging
We are focused on delineating when and where brain activity begins to diverge to different networks when processing speech versus non-speech cues, to reflect categorical perception, rather than the acoustics of the sound. To this end, the spatio-temporal distributions of brain current densities are compared during processing of speech and non-speech sounds discriminated by temporal and spectral cues. Behavioral performance, measured as reaction time, and accuracy of performance as well as electrophysiological functional imaging, using sLORETA and SnPM statistics, are employed to characterize the distributions and timing of brain activity in response to the different sounds. Imaging involves 64-channel records from the scalp, separately averaged for each stimulus condition. We anticipate our findings will not only advance understanding of normal hearing but also facilitate treatment of patients suffering from communication disorders, neurological diseases and normal aging.
Current density distributions in the brain during processing of the very same sounds (Sine-Wave-Speech) when they are perceived as speech or non-speech. Note that the very same physical stimulus evokes a different pattern of brain activity when it is perceived as speech or non-speech.
Pratt H, Abbasi DA, Bleich N, Mittelman N and Starr A: Spatiotemporal Distribution of Cortical Processing of First and Second Languages in Bilinguals. I. Effects of Proficiency and Linguistic Setting. Human Brain Mapping (in press).
Pratt H, Abbasi DA, Bleich N, Mittelman N and Starr A: Spatiotemporal Distribution of Cortical Processing of First and Second Languages in Bilinguals. II. Effects of Phonologic and Semantic Priming. Human Brain Mapping (in press).
Dimitrijevic A, Starr A, Bhatt S, Michalewski HJ, Zeng F-G, Pratt H. 2011. Auditory cortical N100 in pre- and post-synaptic auditory neuropathy to frequency or intensity changes of continuous tones. Clinical Neurophysiology 122, 594–604.