Schedule of Events | Symposia

Rhythmic and Aperiodic Activity jointly guide the allocation of selective spatial attention

Poster Session A - Saturday, March 29, 2025, 3:00 – 5:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Isabel Raposo¹ (isabel.raposo@student.uni-tuebingen.de), Randolph F. Helfrich¹; ¹Hertie Institute for Clinical Brain Research

Attention samples visual space sequentially to enhance behaviorally-relevant sensory representations. While traditionally conceptualized as a static continuous spotlight, contemporary models of attention suggest that the environment is sampled in a discrete manner at a theta rhythm (3-8 Hz). But which other neural mechanisms govern the temporally precise allocation of attention? Periodic brain activity as exemplified by neuronal oscillations as well as aperiodic temporal structure in the form of timescales have been suggested to orchestrate the attentional sampling process in space and time. However, both mechanisms have been largely studied in isolation. To date it remains unclear how periodic and aperiodic temporal structures interact to give rise to multiple attention phenomena, such as the inhibition of return (IOR). Here, we simultaneously investigate these processes and their contributions to attention dynamics, using a temporally fine-grained adaptation of the Posner paradigm, designed to quantify multiple temporal regularities. The behavioral results from 22 patients who underwent intracranial EEG monitoring revealed two overlapping, yet dissociable temporal dynamics: an aperiodic decay function and theta-band modulation of reaction times. Neurophysiologically, we observe that intrinsic timescales and theta oscillations index these two distinct temporal profiles of attention. By integrating behavioral and neural data, we disentangle the rhythmic and aperiodic processes and show their interplay in shaping spatio-temporal attention dynamics in large-scale neocortical circuits centered on the fronto-parietal attention network.

Topic Area: ATTENTION: Spatial