title: Task-specific modulation of human auditory evoked response in a delayed-match-to-sample task.
abstract: In this study, we focus our investigation on task-specific cognitive modulation of early cortical auditory processing in human cerebral cortex. During the experiments, we acquired whole-head magnetoencephalography data while participants were performing an auditory delayed-match-to-sample (DMS) task and associated control tasks. Using a spatial filtering beamformer technique to simultaneously estimate multiple source activities inside the human brain, we observed a significant DMS-specific suppression of the auditory evoked response to the second stimulus in a sound pair, with the center of the effect being located in the vicinity of the left auditory cortex. For the right auditory cortex, a non-invariant suppression effect was observed in both DMS and control tasks. Furthermore, analysis of coherence revealed a beta band (12∼20 Hz) DMS-specific enhanced functional interaction between the sources in left auditory cortex and those in left inferior frontal gyrus, which has been shown to be involved in short-term memory processing during the delay period of DMS task. Our findings support the view that early evoked cortical responses to incoming acoustic stimuli can be modulated by task-specific cognitive functions by means of frontal-temporal functional interactions.
authors.affiliation: Brain Imaging and Modeling Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health Bethesda, MD, USA.
authors.forename: Feng
authors.initials: F
authors.lastname: Rong
authors.forename: Tom
authors.initials: T
authors.lastname: Holroyd
authors.forename: Fatima T
authors.initials: FT
authors.lastname: Husain
authors.forename: Jose L
authors.initials: JL
authors.lastname: Contreras-Vidal
authors.forename: Barry
authors.initials: B
authors.lastname: Horwitz