title: Brain activity associated with dual-task management differs depending on the combinations of response modalities.
abstract: Several functional imaging studies have demonstrated the importance of fronto-parietal network in dual-task management. However, neural correlates underlying the difference in intensity of dual-task interference between the same and different response modalities remain unknown. Therefore, we investigated the relationship between brain activity associated with dual-task management and the combinations of response modalities. We used the dual-task requiring bilateral finger responses (DT-same condition) and that requiring finger and oral responses (DT-different condition) to visual and auditory stimuli. The right premotor cortex, precuneus and right posterior parietal cortex were significantly activated in the DT-same condition. The neural activities in the right premotor cortex significantly correlated to the delayed responses in the DT-same condition relative to the single-task conditions, indicating that the right premotor cortex is partly associated with dual-task management (i.e., the regulation of information flow). In addition, neural activity in this brain region was significantly higher in the DT-same condition than in the DT-different condition, suggesting that the difference in intensity between the same and different response modalities is partly associated with difference in the load on the premotor cortex between the DT-same and DT-different conditions. The significant activation of the parietal cortex also differed between the DT-same and DT-different conditions. These results demonstrate that brain activity associated with dual-task management differs depending on the combination of response modalities and that such a difference in brain activity, particularly in the right premotor cortex, might be partly associated with the difference in intensity of dual-task interference between the DT-same and DT-different conditions.
authors.affiliation: Department of Sensory-Motor Integration, National Institute for Physiological Sciences, 38 Nishigonaka, Myodaiji, Okazaki, Aichi, Japan. motiz@nips.ac.jp
authors.forename: Hideki
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Manabu
authors.initials: M
authors.lastname: Tashiro
authors.forename: Jiro
authors.initials: J
authors.lastname: Gyoba
authors.forename: Miho
authors.initials: M
authors.lastname: Suzuki
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Okamura
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Itoh
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yanai
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation / Q000502:physiology; D007839:Functional Laterality; D006801:Humans; D008297:Male; D010775:Photic Stimulation / Q000379:methods*; D049268:Positron-Emission Tomography; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013223:Statistics as Topic