Schedule of Events | Symposia

Consistent alignment of saccades and alpha oscillations supports the neural representation and memory encoding of visual objects

Poster Session C - Sunday, March 30, 2025, 5:00 – 7:00 pm EDT, Back Bay Ballroom/Republic Ballroom
Also presenting in Data Blitz Session 1 - Saturday, March 29, 2025, 10:30 am – 12:00 pm EDT, Grand Ballroom.

Graham Flick^1,2 (gflick@research.baycrest.org), Jed Meltzer^1,2, Jennifer D. Ryan^1,2, Rosanna K. Olsen^1,2; ¹Baycrest Centre, ²University of Toronto

Visual memories rest upon input from saccades and gaze fixations. Prior work has highlighted a functional link between neural oscillations in visual cortex and the timing of eye movements for memory encoding: saccades synchronized to consistent phases of alpha oscillations are associated with better memory for visual scenes (Staudigl et al., 2017, PLOS Biol). Here, we tested the hypothesis that saccade-alpha phase alignment improves perceptual representations, which may facilitate the memory benefit. Simultaneous magnetoencephalography (MEG) and eye-tracking were recorded in 32 participants. On each trial, participants maintained central fixation before saccading to an object in the periphery. After a delay, recognition memory was tested for 250 viewed objects. Matching past work, saccades to subsequently remembered objects were preceded by greater phase alignment in alpha oscillations (8-12 Hz, -215-0ms) over visual cortex, compared to objects that would be forgotten. Representational similarity analysis of MEG responses time-locked to eye movements revealed that visual representations, defined from a deep convolutional neural network model, emerged in brain activity before the initial saccade (-100-0ms), whereas both visual and semantic representations, the latter defined from semantic property norms, emerged afterwards (0-300ms). Compared to later-forgotten items, saccades onto subsequently remembered objects elicited stronger visual, but not semantic, representations in MEG responses (0-100ms, p = 0.002). Critically, memory-related differences in the strength of these representations were positively associated with differences in pre-saccade alpha phase alignment (r = 0.39, p = 0.048). Altogether, this suggests that alignment between saccades and neural oscillations leads to perceptual enhancement, supporting memory encoding.

Topic Area: LONG-TERM MEMORY: Episodic