title: Processing of spatial sounds in human auditory cortex during visual, discrimination and 2-back tasks.
abstract: Previous imaging studies on the brain mechanisms of spatial hearing have mainly focused on sounds varying in the horizontal plane. In this study, we compared activations in human auditory cortex (AC) and adjacent inferior parietal lobule (IPL) to sounds varying in horizontal location, distance, or space (i.e., different rooms). In order to investigate both stimulus-dependent and task-dependent activations, these sounds were presented during visual discrimination, auditory discrimination, and auditory 2-back memory tasks. Consistent with previous studies, activations in AC were modulated by the auditory tasks. During both auditory and visual tasks, activations in AC were stronger to sounds varying in horizontal location than along other feature dimensions. However, in IPL, this enhancement was detected only during auditory tasks. Based on these results, we argue that IPL is not primarily involved in stimulus-level spatial analysis but that it may represent such information for more general processing when relevant to an active auditory task.
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland ; Advanced Magnetic Imaging Centre, Aalto University School of Science Espoo, Finland.
authors.forename: Teemu
authors.initials: T
authors.lastname: Rinne
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland.
authors.forename: Heidi
authors.initials: H
authors.lastname: Ala-Salomäki
authors.affiliation: Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland ; Department of Hearing and Speech Sciences, Vanderbilt University Medical Center Nashville, TN, USA.
authors.forename: G Christopher
authors.initials: GC
authors.lastname: Stecker
authors.affiliation: Department of Media Technology, Aalto University School of Science Espoo, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Pätynen
authors.affiliation: Department of Media Technology, Aalto University School of Science Espoo, Finland.
authors.forename: Tapio
authors.initials: T
authors.lastname: Lokki
keywords: auditory cortex; fMRI; spatial processing