Perceptual Rhythms

Abstract

It is increasingly evident that brain function involves oscillatory activity in various frequency bands. This realization encouraged psychologists to consider that perception and cognition may operate periodically, as a succession of cycles mirroring the underlying oscillatory cycles. This idea, related to the age‐old notion of discrete perception, has resurfaced in recent years, fueled by advances in neuroscientific techniques. Contrary to earlier views of discrete perception as a unitary sampling rhythm affecting all perceptual and cognitive functions, contemporary evidence points not to one but several rhythms of perception that may depend on the sensory modality, the task, the stimulus, the brain region(s) involved, or the state of the subject. In the visual domain for example, a sensory alpha rhythm (∼10 Hz) may coexist with at least one more rhythm performing attentional sampling around 7 Hz. How these multiple periodic functions coordinate with each other and how internal sampling rhythms coordinate with overt sampling behavior are key questions for the future.

Object-based attention prioritizes working memory contents at a theta rhythm

“…Across trials, behavioral performance (e.g., target detection rate) then varies over time since cue onset in a rhythmic fashion at frequencies in the theta and alpha ranges (approx. 4-12 Hz) (VanRullen, 2016b). These fluctuations of performance strongly contradict the long held assumption of continuous attentional processing, which would predict constant or increasing performance with time since cue onset.…”

“…It is a long-standing notion that the continuous stream of sensory information is sampled discretely by the perceptual system (VanRullen, 2016b). Recently, a series of psychophysical studies have demonstrated attentional sampling in tasks including visual target detection (Dugué et al, 2015;Landau & Fries, 2012;VanRullen et al, 2007), discrimination (Song et al, 2014), and priming (Huang et al, 2015), as well as auditory target discrimination (Ho et al, 2017).…”

Transcranial Magnetic Stimulation Reveals Intrinsic Perceptual and Attentional Rhythms

“…In the past decade, accumulating evidence has demonstrated the predictive nature of the spectral components of ongoing oscillations (i.e., phase and amplitude) on perceptual processes (VanRullen et al, 2011; VanRullen, 2016, in press). Interestingly, TMS, and in particular spTMS due to its high temporal and spatial resolution compared with other stimulation techniques such as tACS/tDCS (Paus et al, 2001; Miniussi et al, 2013), can be used to characterize spontaneous activity and its role on perceptual processes.…”

“…Recently, in a comprehensive review of the oscillation literature, VanRullen reported that two types of perceptual rhythms can coexist in the visual domain: an alpha rhythm (~10 Hz) that would be associated with sensory processes, and a theta rhythm (~7 Hz) that would be associated with attentional sampling (VanRullen, 2016, in press). spTMS studies reported in the previous section offer to extend this observation.…”

“…To address this question, one can focus on spontaneous oscillatory activity and its predictive nature for subsequent processing (VanRullen et al, 2011; VanRullen, 2016, in press). If neural oscillations have a specific, functional role, then it is possible to link their spectral properties (frequency, phase, and amplitude) to perceptual and/or cognitive processes assessed via behavioral measurements.…”