title: Attentional modulation of human auditory cortex.
abstract: Attention powerfully influences auditory perception, but little is understood about the mechanisms whereby attention sharpens responses to unattended sounds. We used high-resolution surface mapping techniques (using functional magnetic resonance imaging, fMRI) to examine activity in human auditory cortex during an intermodal selective attention task. Stimulus-dependent activations (SDAs), evoked by unattended sounds during demanding visual tasks, were maximal over mesial auditory cortex. They were tuned to sound frequency and location, and showed rapid adaptation to repeated sounds. Attention-related modulations (ARMs) were isolated as response enhancements that occurred when subjects performed pitch-discrimination tasks. In contrast to SDAs, ARMs were localized to lateral auditory cortex, showed broad frequency and location tuning, and increased in amplitude with sound repetition. The results suggest a functional dichotomy of auditory cortical fields: stimulus-determined mesial fields that faithfully transmit acoustic information, and attentionally labile lateral fields that analyze acoustic features of behaviorally relevant sounds.
authors.affiliation: Center for Neuroscience, UC Davis, 1544 Newton Court, Davis, California 95616, USA.
authors.forename: Christopher I
authors.initials: CI
authors.lastname: Petkov
authors.forename: Xiaojian
authors.initials: X
authors.lastname: Kang
authors.forename: Kimmo
authors.initials: K
authors.lastname: Alho
authors.forename: Olivier
authors.initials: O
authors.lastname: Bertrand
authors.forename: E William
authors.initials: EW
authors.lastname: Yund
authors.forename: David L
authors.initials: DL
authors.lastname: Woods
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D001288:Attention / Q000502:physiology*; D001303:Auditory Cortex / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D011597:Psychomotor Performance / Q000502:physiology*