Attention systems and neural responses to visual and auditory stimuli: an fMRI study

Abstract

Visual orienting attention has been researched thoroughly using visual cues, and spatial attention and temporal attention have been compared using brain-imaging data [1]. However, while several studies have reported on auditory attention, the attention was not oriented using a cue. In addition, fewer studies have compared spatial and temporal attention using auditory stimuli. We compared visual and auditory orienting attention using a visual cue. We asked whether a general system exists for auditory spatial and temporal attention that conforms to that of visual spatial and temporal attention. We measured brain activity in 16 healthy volunteers using functional magnetic resonance imaging (fMRI). The attention was manipulated spatially and temporally using a visual cue for both visual and auditory tasks in a factorial design. Symbolic central cues oriented the subjects toward spatial location only (left or right), toward the temporal interval only (300 or 1800 ms), or gave no information about the spatial location or temporal interval. The subjects were also scanned under a resting baseline condition during which they clicked the reaction key ten times. Behavioral data showed the same tendency in visual and auditory tasks. The reaction time for spatial location attention was faster than that for temporal interval attention. The brain-imaging data showed a partial overlap between visual spatial attention and auditory spatial attention. In addition, it revealed a partial overlap between the neural systems involved in the performance of visual spatial attention versus visual temporal attention. The parietal and frontal cortices were activated in both the visual and auditory spatial attention tasks. The parietal cortex was activated in the visual temporal attention task only and not in the auditory temporal task.