Perceptual cycles in vision and audition
Recent (and less recent) evidence suggests that visual perception and attention are intrinsically rhythmic. For example, in a variety of visual tasks, the trial-by-trial outcome was found to depend on the precise phase of spontaneous pre-stimulus EEG oscillations in specific frequency bands (between 7 and 15Hz). This implies that there are “good” and “bad” phases for visual perception and attention; in other words, visual perception and attention proceed as a succession of ongoing cycles. On the other hand, auditory processing does not appear to be shaped in a similar way by spontaneous brain oscillations. Particularly in the context of speech processing, where the rhythmic structure of the inputs carries important information, neural oscillations are dynamically adjusted to this input structure. As a result, auditory perceptual cycles, if they exist, would not just shape sensory perception (as in vision), but also be shaped by it.