title: Examining the role of frequency specificity in the enhancement and suppression of human cortical activity by auditory selective attention.
abstract: This study examined the neural basis of auditory selective attention using functional magnetic resonance imaging. The main hypothesis stated that attending to a particular sound frequency would significantly enhance the neural response within those tonotopic regions of the auditory cortex sensitive to that frequency. To test this prediction, low- and high-frequency sound sequences were interleaved to produce two concurrent auditory streams. Six normally hearing participants either performed a task which required them to attend to one or the other stream or listened passively to the sounds while functional images were acquired using a high-resolution (1.5 mm x 1.5 mm x 2.5 mm) sequence. Two statistical comparisons identified the attention-specific and general effects of enhancement. The first controlled for task-related processes, while the second did not. Results demonstrated frequency-specific, attention-specific enhancement in the response to the attended frequency, but no response suppression for the unattended frequency. Instead, a general effect of suppression was found in several posterior sites, possibly related to resting-state processes. Furthermore, there was widespread general enhancement across auditory cortex when performing the task compared to passive listening. This enhancement did include frequency-sensitive regions, but was not restricted to them. In conclusion, our results show partial support for frequency-specific enhancement.
authors.affiliation: MRC Institute of Hearing Research, University Park, Nottingham NG7 2RD, UK. aspa.paltoglou@abdn.ac.uk
authors.forename: Aspasia E
authors.initials: AE
authors.lastname: Paltoglou
authors.forename: Christian J
authors.initials: CJ
authors.lastname: Sumner
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Hall
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001288:Attention; D001299:Audiometry; D001303:Auditory Cortex / Q000502:physiology*; D001307:Auditory Perception; D001931:Brain Mapping / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D010470:Perceptual Masking; D013647:Task Performance and Analysis; D055815:Young Adult