Studies in healthy right-handed subjects (N = 16, mean age 23 ± 5.7 years) analyzed the functional organization of the cerebral cortex during preparation to solve visual and auditory sensory tasks in two conditions: (1) anticipation of a visual or auditory signal after being told its modality (cued anticipatory attention) and (2) implicit anticipation formed during multiple repetition of a given sequence of visual and auditory stimuli. In both conditions subjects had to perform the same task – to identify the order of the stimuli (visual or auditory) in monomodal pairs. During the prestimulus period, the α frequency range was used to assess the coherence of cortical sources corresponding to previously selected cortical regions (regions of interest). More functional connections between cortical zones in the frontoparietal modulatory system were seen in cued anticipatory attention than during the period preceding appearance of the prompt stimulus, this obtaining in both sensory tasks. There was also a greater number of local connections between sensory-specific and associative (parietal and prefrontal) areas. Implicit anticipation preceding execution of the visual task was accompanied by an increase in connections between the ventral premotor cortex and the caudal (parietal and occipital) areas of the right hemisphere. Execution of the auditory task was preceded by an increase in connections between the auditory sensory cortex, the rostral part of the supplementary motor area, and the ventral premotor area. In contrast to cued attention, implicit anticipation was not accompanied by changes in frontoparietal connections. These results provide evidence of significant differences in the cerebral organization of these two types of anticipatory attention.
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