PT  - JOURNAL ARTICLE
AU  - Eelke de Vries
AU  - Freek van Ede
TI  - Microsaccades track location-based object rehearsal in visual working memory
AID  - 10.1101/2023.03.21.533618
DP  - 2023 Jan 01
TA  - bioRxiv
PG  - 2023.03.21.533618
4099  - http://biorxiv.org/content/early/2023/03/24/2023.03.21.533618.short
4100  - http://biorxiv.org/content/early/2023/03/24/2023.03.21.533618.full
AB  - Besides controlling eye movements, the brain’s oculomotor system has been implicated in the control of covert spatial attention and the rehearsal of spatial information in working memory. We investigated whether the oculomotor system also contributes to rehearsing visual objects in working memory when object location is never asked about. To address this, we tracked the incidental use of locations for mnemonic rehearsal via directional biases in microsaccades while participants maintained two visual objects (coloured oriented gratings) in working memory. By varying the stimulus configuration (horizontal, diagonal, and vertical) at encoding, we could quantify whether microsaccades were more aligned with the configurational axis of the memory contents, as opposed to the orthogonal axis. Experiment 1 revealed that microsaccades continued to be biased along the axis of the memory content several seconds into the working-memory delay. In Experiment 2, we confirmed that this directional microsaccade bias was specific to memory demands, ruling out lingering effects from passive and attentive encoding of the same visual objects in the same configurations. Thus, by studying microsaccade directions, we uncover oculomotor-driven rehearsal of visual objects in working memory through their associated locations.Competing Interest StatementThe authors have declared no competing interest.