Spatial attention and lateralized pre-stimulus alpha shape iconic memory via inhibition

Authors

Smith, P. J. C., Busch, N. A.

Abstract

The earliest stage of visual memory is often characterized as pre-attentive, yet recent work suggests that spatial attention and pre-stimulus alpha oscillations both shape iconic memory at its onset. Whether these influences reflect a common inhibitory mechanism or contribute independently is unknown. We combined an endogenous spatial pre-cue (valid, invalid, neutral) with an analysis of pre-stimulus alpha power in a partial-report paradigm, at target-to-post-cue onset asynchronies (SOAs) of 0, 120, and 1240 ms, while recording EEG from 45 participants. Behaviorally, perceptual sensitivity (d') showed a cost-dominated signature: invalid cues impaired performance relative to both neutral and valid cues at the 0 and 120 ms SOAs, with no benefit of valid over neutral cues. The pre-stimulus EEG mirrored this asymmetry: at 120 ms, stronger alpha power ipsilateral to the target predicted higher d', whereas contralateral alpha had no effect at any SOA, indicating suppression of the irrelevant hemifield rather than facilitation of the target. This ipsilateral effect was additive with cue validity rather than interactive, and it persisted in neutral trials without any directional cue. Iconic memory is thus continuously biased by the inhibitory state of early visual cortex, to which endogenous attention and spontaneous excitability fluctuations contribute through separable channels.

Preprint server: bioRxiv
The authors list and abstract were imported from bioRxiv on 06 Aug 2026.

Stats

1-terrible, 9-excellent. How would you rate this preprint? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.