title: Task-demands and audio-visual stimulus configurations modulate neural activity in the human thalamus.
abstract: Recent electrophysiological studies have reported short latency modulations in cortical regions for multisensory stimuli, thereby suggesting a subcortical, possibly thalamic origin of these modulations. Concurrently, there is an ongoing debate, whether multisensory interplay reflects automatic, bottom-up driven processes or relies on top-down influences. Here, we dissociated the effects of task set and stimulus configurations on BOLD-signals in the human thalamus with event-related functional magnetic resonance imaging (fMRI). We orthogonally manipulated temporal and spatial congruency of audio-visual stimulus configurations, while subjects judged either their temporal or spatial congruency. Voxel-based fMRI results revealed increased fMRI-signals for the temporal versus spatial task in posterior and central thalamus, respectively. A more sensitive region of interest (ROI)-analysis confirmed that the posterior thalamic nuclei showed a preference for the temporal task and central thalamic nuclei for the spatial task. Moreover, the ROI-analysis also revealed enhanced fMRI-signals for spatially incongruent stimuli in the central thalamus. Together, our results demonstrate that both audio-visual stimulus configurations and task-related processing of spatial or temporal stimulus features selectively modulate thalamic processing and thus are in a position to influence cortical processing at an early stage.
authors.affiliation: Institute of Biological Psychology, Otto-von-Guericke University, Magdeburg, Germany. bjoern.bonath@ovgu.de
authors.forename: Björn
authors.initials: B
authors.lastname: Bonath
authors.forename: Sascha
authors.initials: S
authors.lastname: Tyll
authors.forename: Eike
authors.initials: E
authors.lastname: Budinger
authors.forename: Kerstin
authors.initials: K
authors.lastname: Krauel
authors.forename: Jens-Max
authors.initials: JM
authors.lastname: Hopf
authors.forename: Tömme
authors.initials: T
authors.lastname: Noesselt
mesh_terms: D000328:Adult; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008297:Male; D020656:Posterior Thalamic Nuclei / Q000502:physiology; D013028:Space Perception / Q000502:physiology; D013788:Thalamus / Q000166:cytology / Q000502:physiology*; D013998:Time Perception / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*; D055815:Young Adult