Cortical Spatio-temporal Dynamics Underlying Phonological Target Detection in Humans


Selective processing of task-relevant stimuli is critical for goal-directed behavior. We used electrocorticography to assess the spatio-temporal dynamics of cortical activation during a simple phonological target detection task, in which subjects press a button when a prespecified target syllable sound is heard. Simultaneous surface potential recordings during this task revealed a highly ordered temporal progression of high gamma (HG, 70-200 Hz) activity across the lateral hemisphere in less than 1 sec. The sequence demonstrated concurrent regional sensory processing of speech syllables in the posterior superior temporal gyrus (STG) and speech motor cortex, and then transitioned to sequential task-dependent processing from prefrontal cortex (PFC), to the final motor response in the hand sensorimotor cortex. STG activation was modestly enhanced for target over nontarget sounds, supporting a selective gain mechanism in early sensory processing, whereas PFC was entirely selective to targets, supporting its role in guiding response behavior. These results reveal that target detection is not a single cognitive event, but rather a process of progressive target selectivity that involves large-scale rapid parallel and serial processing in sensory, cognitive, and motor structures to support goal-directed human behavior.

DOI: 10.1162/jocn.2010.21466

Extracted Key Phrases

4 Figures and Tables

Citations per Year

70 Citations

Semantic Scholar estimates that this publication has 70 citations based on the available data.

See our FAQ for additional information.

Cite this paper

@article{Chang2011CorticalSD, title={Cortical Spatio-temporal Dynamics Underlying Phonological Target Detection in Humans}, author={Edward F. Chang and Erik Edwards and Srikantan S. Nagarajan and Noa Fogelson and Sarang S. Dalal and Ryan T. Canolty and Heidi E. Kirsch and Nicholas M. Barbaro and Robert T. Knight}, journal={Journal of cognitive neuroscience}, year={2011}, volume={23 6}, pages={1437-46} }