Competing neural responses for auditory and visual decisions.
Why is it hard to divide attention between dissimilar activities, such as reading and listening to a conversation? We used functional magnetic resonance imaging (fMRI) to study interference between simple auditory and visual decisions, independently of motor competition. Overlapping activity for auditory and visual tasks performed in isolation was found in lateral prefrontal regions, middle temporal cortex and parietal cortex. When the visual stimulus occurred during the processing of the tone, its activation in prefrontal and middle temporal cortex was suppressed. Additionally, reduced activity was seen in modality-specific visual cortex. These results paralleled impaired awareness of the visual event. Even without competing motor responses, a simple auditory decision interferes with visual processing on different neural levels, including prefrontal cortex, middle temporal cortex and visual regions.
Hein
Grit
G
Cognitive Neurology Unit, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. ghein@berkeley.edu
Alink
Arjen
A
Kleinschmidt
Andreas
A
Müller
Notger G
NG
D001288:Attention / Q000502:physiology*; D001307:Auditory Perception / Q000502:physiology*; D001931:Brain Mapping; D007839:Functional Laterality; D006801:Humans; D009043:Motor Activity / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D010296:Parietal Lobe / Q000502:physiology; D013702:Temporal Lobe / Q000502:physiology; D014793:Visual Cortex / Q000502:physiology*; D014796:Visual Perception / Q000502:physiology*