To experience the multisensory world around us, our brain has the capability to integrate inputs from different sensory channels, while disregarding ones that do not belong to the same event. Timing of the inputs appears to be one of the key factors in this process. Neuronal oscillations have long been suspected as timekeepers in the brain. They are also ideal candidates for the dynamical coupling of distant cortical areas and thereby link inputs from different senses. The pre-requisite for both of these processes is the phase reset of neural oscillations by select events.
We analyzed laminar profiles of field potentials and multiunit activity sampled during linear array multielectrode penetrations of primary auditory and visual cortices in awake macaques. We show that event related phase reset of neural oscillations in primary cortical areas occurs independent of their modality, and that attention plays a key role in this process. The phase reset of ambient neuronal oscillations by attended stimuli results in coherent neural oscillations across auditory and visual cortex in multiple frequency bands. These results suggest that attention plays the role of a conductor in orchestrating what type of inputs will re-set ongoing activity, which in turn can couple distant cortical areas and together with the structure of ambient oscillations determines the time window for possible multisensory interaction.