Dynamic Predictions: Oscillatory Mechanisms Underlying Multisensory Sequence Processing
Neural oscillations have been proposed to be involved in predictive processing by frequency specific modulation of either power or phase. While this is supported by substantial evidence on unimodal processing, only few studies are currently available that have addressed the role of oscillatory activity in multisensory predictions. In the present study, we have recorded MEG during a serial prediction task in which participants had to acquire stimulus sequences and to monitor whether subsequent probe items complied with the sequence. The sequences comprised combinations of visual and auditory stimuli, but on a given trial, only one of the modalities was task relevant and the other had to be ignored. Task related changes of power and coupling of neural oscillations were analyzed using a data driven clustering approach. We observed prediction related theta band coupling in a network involving cingulate, premotor, prefrontal and superior temporal regions. Behavioral performance of the participants correlated with phase delays between remote regions in this network. Two additional clusters were detected where beta power were stronger when the previous or next stimuli were same as the current one in the sequence. These clusters interacted with the theta band prediction network through cross frequency coupling. Furthermore, we observed asymmetrical effects of attention to the visual and auditory modalities in a network distinguished by changes in alpha power, where alpha phases modulated response times. Overall, our results provide novel insights into the neural dynamics underlying multisensory predictions and suggest that oscillations in multiple frequency ranges as well as coupling within and across frequencies may be critical for sequence processing.