Cortical spatio-temporal dynamics underlying phonological target detection in humans

Edward F. Chang, Erik Edwards, Srikantan S. Nagarajan, Noa Fogelson, Sarang S. Dalal, Ryan T. Canolty, Heidi E. Kirsch, Nicholas M. Barbaro, Robert T. Knight

Research output: Contribution to journalArticlepeer-review

45 Scopus citations


Selective processing of task-relevant stimuli is critical for goaldirected 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.

Original languageEnglish (US)
Pages (from-to)1437-1446
Number of pages10
JournalJournal of Cognitive Neuroscience
Issue number6
StatePublished - Jun 2011

ASJC Scopus subject areas

  • Cognitive Neuroscience

Fingerprint Dive into the research topics of 'Cortical spatio-temporal dynamics underlying phonological target detection in humans'. Together they form a unique fingerprint.

Cite this