Schedule of Events | Symposia

Microsaccades strongly modulate but do not necessarily cause the N2pc EEG marker of spatial attention shifts in perception and working memory

Poster Session A - Saturday, March 29, 2025, 3:00 – 5:00 pm EDT, Back Bay Ballroom/Republic Ballroom
Also presenting in Data Blitz Session 2 - Saturday, March 29, 2025, 10:30 am – 12:00 pm EDT, Independence Ballroom.

Freek van Ede¹ (freek.van.ede@vu.nl), Siyang Kong¹, Baiwei Liu¹; ¹Vrije Universiteit Amsterdam

The N2pc is a popular human-neuroscience marker of covert and internal spatial attention that occurs 200-300 ms after being prompted to shift attention – a time window also characterised by the spatial biasing of small fixational eye-movements known as microsaccades. To delineate the relation between these co-occurring spatial modulations, we conducted a combined EEG-eyetracking study where a central colour cue prompted covert or internal selection of a left/right visual target that was either visible (selection from perception) or held in working memory (selection from memory). We show how co-occurring microsaccades profoundly modulate N2pc amplitude during top-down shifts of spatial attention in both perception and working memory. At the same time, we show that a significant – albeit severely weakened – N2pc can still be established in the absence of co-occurring microsaccades. Thus, while microsaccade presence and direction strongly modulate N2pc amplitude, microsaccades are not strictly a prerequisite for the N2pc to be observed. Moreover, this relation holds no matter whether microsaccades also bring attended visual targets closer to the fovea (in perception) or not (in working memory).

Topic Area: ATTENTION: Spatial