Rhythms of vision: How neural oscillations structure perception and attention

Symposium: Friday, May 15, 2026, 8:00 – 10:00 am, Talk Room 2

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Organizers: April Pilipenko¹, Jason Samaha¹; ¹University of California, Santa Cruz
Presenters: David Melcher, Joey Zhou, April Pilipenko, Luca Ronconi, Ian Fiebelkorn, Ayelet Landau

A growing body of work demonstrates that perception is not continuous but fluctuates rhythmically, shaped by dynamic interactions between oscillatory and aperiodic neural activity across the visual system. This symposium brings together six complementary research programs that collectively advance our understanding of how endogenous brain rhythms structure perception, attention, and decision-making. Together, these talks highlight how oscillations in the theta (3-8 Hz), alpha (8-12 Hz), and beta (13-30 Hz) frequency bands, along with aperiodic neural dynamics, govern temporal integration, sensory encoding, visuospatial processing, attentional selection, and the resolution of neural competition. The first talk examines how individual differences in alpha oscillations and aperiodic activity jointly determine the temporal binding windows that govern whether visual events are integrated or segmented. These results suggest a framework in which oscillatory sampling, neural noise regulation, and perceptual history together shape the temporal resolution of visual experience. The second presentation extends this perspective by revealing that alpha is not a unitary phenomenon: network-level MEG analyses show that multiple, functionally distinct alpha networks dynamically recur during perceptual decisions, each exerting different influences on cortical excitability and sensory evidence. Next, a series of EEG and psychophysics studies demonstrates how alpha power and phase shape early visual encoding. High alpha power shifts perceptual criterion, while optimal alpha phases maximize sensitivity by reducing trial-to-trial variability and sharpening feature tuning, providing a mechanistic account of how spontaneous alpha rhythms regulate sensory fidelity. Complementing these findings, new evidence highlights a central role for beta oscillations in dorsal-stream visuospatial processing, motion perception, and oculomotor control. Beyond basic mechanisms, beta-targeted neurostimulation in adults with dyslexia yields improvements in reading fluency and visuospatial working memory, pointing to translational applications of oscillatory research. The final two talks focus on the rhythmic nature of selective attention. One line of work shows that attention alternates at theta frequencies between states that enhance sensory sampling and states that promote attentional shifting, creating periodic fluctuations in perceptual sensitivity and susceptibility to distraction both in perception and in working memory. The concluding talk extends this rhythmic perspective to attentional competition, demonstrating that when multiple objects vie for representation, attentional sampling slows from ~8 Hz to ~4 Hz, reflecting the division of processing resources across competing neural populations. By integrating insights across spatial scales, frequency bands, and methodological approaches, this symposium showcases how oscillatory dynamics provide a unifying framework for understanding visual processing as an intrinsically rhythmic and dynamically structured phenomenon.

Talk 1

The role of alpha oscillations and aperiodic neural activity in the temporal organization of visual perception

David Melcher¹, Michele Deodato¹, Gianluca Marsicano¹; ¹NYU Abu Dhabi

Visual perception requires integrating sensory input over time, as well as segmenting the continuous flow into discrete events. Across a number of studies, we have investigated the role of oscillatory and aperiodic neural activity in this integration/segregation process. In particular, we have focused on individual differences and trial-by-trial variability in the temporal binding windows which define whether two stimuli are combined into a single, coherent percept or segmented into unique events. Here, we will present converging results from multiple paradigms, ranging from presentation of brief flashes to continuous streams of stimuli and judgments of causality from Michotte-style collision events. Using either resting-state EEG or event-related EEG during the psychophysical paradigm, we consistently find that alpha oscillatory activity and aperiodic activity combine to predict individual differences in perceptual judgments. Faster individual alpha rhythms were associated with narrower temporal integration windows, and a steeper aperiodic spectrum (lower neural noise) predicted greater perceptual precision (Deodato & Melcher, 2024). Moreover, individuals with slower alpha frequencies and flatter spectra showed stronger reliance on prior perceptual judgments. Subjective confidence was also linked to peak alpha frequency, with faster rhythms supporting higher certainty. Together, these findings suggest that temporal binding arises from the joint influence of the alpha rhythm and aperiodic neural activity. Faster alpha rhythms may promote greater perceptual resolution by generating more sensory samples per time unit, resulting in higher temporal precision, reduced reliance on prior perceptual experience, and greater subjective confidence in perceptual decisions.

Talk 2

Dual alpha mechanisms in visual perception

Joey Zhou¹; ¹Shenzhen University

Spontaneous neural oscillations, particularly in the alpha band (8-14 Hz), create rhythmic fluctuations in cortical excitability that influence conscious perception. However, the underlying neural mechanisms through which these oscillations modulate perception remain unclear. Previous work has shown mixed results on how such excitability changes modulate sensory signals of interest versus noise, and what the consequences are for subsequent perception. A probable reason for these conflicting findings is that different alpha networks dominate across different studies. In this presentation, I will address this by introducing a network-based approach to analyze MEG data from visual decision-making tasks. Our results demonstrate that multiple, functionally distinct alpha networks coexist and dynamically recur over time, with each influencing perceptual decision-making through different mechanisms. These findings have important methodological and theoretical implications for characterizing the role of oscillatory activity in perception and decision making.

Talk 3

How spontaneous alpha oscillations modulate sensory encoding

April Pilipenko¹, Jason Samaha¹; ¹University of California, Santa Cruz

Alpha-band (8-12 Hz) neural oscillations recorded from posterior brain regions are strongly associated with visual processing due to their ability to predict trial-to-trial variability in a range of perceptual reports from low-level detection to higher level illusions. Yet, our understanding of the mechanisms by which alpha shapes vision is limited. In this talk, I will present a series of recent EEG studies that integrate psychophysical modeling, signal detection theory, and reverse correlation to characterize the mechanisms by which alpha oscillations modulate early visual encoding. By presenting a range of stimuli that sample an individual’s psychometric function linking stimulus contrast to detection, our first study demonstrates how spontaneous alpha power leads to a liberal shift in criterion during states of weak alpha power rather than an increase in perceptual gain, suggesting an indiscriminate boost in the baseline firing activity of sensory neurons. Our second study focused on the phase of alpha oscillations, revealing that perceptual sensitivity is optimized at specific phases. Double-pass and reverse correlation techniques reveal that optimal alpha phases are associated with a reduction in trial-to-trial variability and sharper perceptual tuning for stimulus-relevant features. Together, these findings provide converging evidence that alpha-band oscillations rhythmically shape visual encoding by dynamically modulating the excitability and synchronization of underlying neural populations. This work advances our understanding of how endogenous neural rhythms shape the fidelity of sensory representations and offers a mechanistic account of alpha’s role in coordinating visual information processing.

Talk 4

Neural oscillatory mechanisms supporting the dorsal visual stream functionality and their restoration in reading disorders

Luca Ronconi¹; ¹University of Trento

Neural oscillations in the alpha (8–12 Hz) and beta (13–30 Hz) frequency bands play a fundamental role in coordinating feedback/re-entrant loops and large-scale cortical interactions. While alpha rhythms have been extensively associated with temporal and featural integration in visual perception, increasing evidence points to beta oscillations as crucial for spatial organization, motion processing, and visuo-spatial attention. Particularly, findings suggest that beta activity within poster parietal regions would sustain the functionality of the dorsal (“where”) visual pathway, providing fast preconscious spatial guidance over the slower ventral (“what”) stream. Crucially, this hierarchical dynamic might be crucial in guiding the extraction of letters/words identity and the oculomotor processes required for fluent reading. I will summarize recent evidence highlighting the role of beta oscillations as a neural code for dorsal pathway functions, integrating findings from human psychophysics, electrophysiology and neurostimulation. I will then present the results of a randomized clinical trial conducted in adults with developmental dyslexia (DD), a condition characterized by visuo-spatial and oculo-motor dysfunctions. The study employed bi-focal beta-band transcranial alternating current stimulation (tACS) over parietal areas, combined with a visuo-attentional training. As compared to a placebo/sham intervention, beta-tACS led to significant improvements in reading speed, oculomotor control, and visual motion perception, as well as long-term gains in visual/auditory working memory. Together, these findings provide converging evidence – from basic research to clinical application – supporting beta-band synchronization as a key mechanism for visuo-spatial and oculo-motor integration and a promising target for rehabilitating reading disorders.

Talk 5

Updating the rhythmic theory of attention

Ian Fiebelkorn¹, Zach Redding¹, Paul Cavanah¹; ¹University of Rochester

Selective attention is a collection of filtering mechanisms through which behaviorally important information receives preferential processing. Recent research has shown that attention-related changes in neural activity (e.g., spiking activity) and behavioral performance (e.g., accuracy) fluctuate during attentional deployment, rather than being sustained over time. We and others have linked such temporal fluctuations in attention-related effects to the phase of frequency-specific neural activity. For example, different phases of theta-band activity (3–8 Hz) are associated with (1) either better or worse perceptual sensitivity at a to-be-attended location and (2) increased spiking among different, functionally defined cell types (i.e., either sensory or sensorimotor neurons). The Rhythmic Theory of Attention proposes that phasic changes in behavioral performance and neural activity reflect alternating attentional states associated with either attention-related sampling (i.e., sensory functions) or an increased likelihood of attention-related shifting (i.e., motor functions). A periodically occurring ‘shifting state’ could be beneficial, e.g., by preventing us from becoming overly focused on any single stimulus. However, a periodically occurring ‘shifting state’ might also make us more susceptible to distracting information (i.e., behaviorally irrelevant information). Here, I will present recent work that demonstrates such rhythmic susceptibility to distractors. Increased susceptibility to distractors occurs during the same phase associated with decreased perceptual sensitivity (i.e., during the proposed ‘shifting state’). I will also present recent work demonstrating that the theta-rhythmic process for selective sampling of environmental information is similarly engaged during selective sampling of internally stored information (e.g., information being held in working memory).

Talk 6

Rhythmic attention negotiates competition along the visual hierarchy

Ayelet Landau¹; ¹Hebrew University of Jerusalem

Navigating the environment involves engaging with multiple objects, each activating specific neuronal populations. When objects appear together, the respective neuronal populations compete. Classical attention theories suggest that selection involves biasing one population over another. Recent research shows that perception fluctuates over time. When a single object is processed over time a ~8 Hz fluctuation seems to govern its perception. When attention is distributed over two different objects a 4 Hz fluctuation is measured, possibly due to the division of the 8 Hz rhythm between competing objects. In my talk I will explore these rhythmic phenomena, coined attentional sampling, across the visual hierarchy. I will argue that sampling is a selection mechanism that negotiates neuronal competition. It manifests as early as eye channels and extends to complex features higher in the visual hierarchy and potentially beyond the visual modality. Finally, I will discuss the cognitive significance of this mechanism and its potential neuronal implementation.