Brain activity during divided and selective attention to auditory and visual sentence comprehension tasks.
Using functional magnetic resonance imaging (fMRI), we measured brain activity of human participants while they performed a sentence congruence judgment task in either the visual or auditory modality separately, or in both modalities simultaneously. Significant performance decrements were observed when attention was divided between the two modalities compared with when one modality was selectively attended. Compared with selective attention (i.e., single tasking), divided attention (i.e., dual-tasking) did not recruit additional cortical regions, but resulted in increased activity in medial and lateral frontal regions which were also activated by the component tasks when performed separately. Areas involved in semantic language processing were revealed predominantly in the left lateral prefrontal cortex by contrasting incongruent with congruent sentences. These areas also showed significant activity increases during divided attention in relation to selective attention. In the sensory cortices, no crossmodal inhibition was observed during divided attention when compared with selective attention to one modality. Our results suggest that the observed performance decrements during dual-tasking are due to interference of the two tasks because they utilize the same part of the cortex. Moreover, semantic dual-tasking did not appear to recruit additional brain areas in comparison with single tasking, and no crossmodal inhibition was observed during intermodal divided attention.
Division of Cognitive Psychology and Neuropsychology, Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland ; Department of Teacher Education, University of Helsinki Helsinki, Finland.
Mona
M
Moisala
Division of Cognitive Psychology and Neuropsychology, Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland ; Advanced Magnetic Imaging Centre, Aalto NeuroImaging, Aalto University Espoo, Finland.
Viljami
V
Salmela
Division of Cognitive Psychology and Neuropsychology, Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland.
Emma
E
Salo
Brain Research Unit, Department of Neuroscience and Biomedical Engineering, Aalto University School of Science Espoo, Finland ; Neuroscience Unit, Institute of Biomedicine/Physiology, University of Helsinki Helsinki, Finland.
Synnöve
S
Carlson
Neuroscience Unit, Institute of Biomedicine/Physiology, University of Helsinki Helsinki, Finland.
Virve
V
Vuontela
Helsinki Medical Imaging Center, Helsinki University Central Hospital Helsinki, Finland.
Oili
O
Salonen
Division of Cognitive Psychology and Neuropsychology, Institute of Behavioural Sciences, University of Helsinki Helsinki, Finland ; Advanced Magnetic Imaging Centre, Aalto NeuroImaging, Aalto University Espoo, Finland ; Helsinki Collegium for Advanced Studies, University of Helsinki Helsinki, Finland ; Swedish Collegium for Advanced Study Uppsala, Sweden.
Kimmo
K
Alho
divided attention; dual-tasking; functional MRI; selective attention; semantic processing