Perception of near‐threshold visual stimuli is influenced by prestimulus alpha‐band amplitude but not by alpha phase

Melcon, M., Stern, E., Kessel, D., Arana, L., Poch, C., Campo, P. and Capilla, A. (2024) Perception of near‐threshold visual stimuli is influenced by prestimulus alpha‐band amplitude but not by alpha phase. Psychophysiology, (doi: 10.1111/psyp.14525) (Early Online Publication)

Abstract

Ongoing brain activity preceding visual stimulation has been suggested to shape conscious perception. According to the pulsed inhibition framework, bouts of functional inhibition arise in each alpha cycle (every ~100 ms), allowing information to be processed in a pulsatile manner. Consequently, it has been hypothesized that perceptual outcome can be influenced by the specific phase of alpha oscillations prior to the stimulus onset, although empirical findings are controversial. In this study, we aimed to shed light on the role of prestimulus alpha oscillations in visual perception. To this end, we recorded electroencephalographic activity, while participants performed three near‐threshold visual detection tasks with different attentional involvement: a no‐cue task, a noninformative cue task (50% validity), and an informative cue task (100% validity). Cluster‐based permutation statistics were complemented with Bayesian analyses to test the effect of prestimulus oscillatory amplitude and phase on visual awareness. We additionally examined whether these effects differed in trials with low and high oscillatory amplitude, as expected from the pulsed inhibition theory. Our results show a clear effect of prestimulus alpha amplitude on conscious perception, but only when alpha fluctuated spontaneously. In contrast, we did not find any evidence that prestimulus alpha phase influenced perceptual outcome, not even when differentiating between low‐ and high‐amplitude trials. Furthermore, Bayesian analysis provided moderate evidence in favor of the absence of phase effects. Taken together, our results challenge the central theoretical predictions of the pulsed inhibition framework, at least for the particular experimental conditions used here.

• Item Type: Articles
• Additional Information: This work was supported by Ministerio de Ciencia, Innovación y Universidades / Agencia Estatal de Investigación, Spain / FEDER, UE (MCIU/AEI/FEDER, UE; grants PGC2018-100682-B-I00 to AC and PC and PID2019-111335GA-I00 to CP); Ministerio de Ciencia e Innovación / Agencia Estatal de Investigación, Spain / FEDER/FSE+, UE (MCIN/AEI/ 10.13039/501100011033 /FEDER/FSE+, UE; PID2021-125841NB-I00 to AC and PRE2022-101613 to ES); and the Comunidad de Madrid, Spain (IND2022/SOC-23652 to LA).
• Status: Early Online Publication
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Melcon, Ms Maria

Creator Roles

Melcon, M.: Conceptualization, Data curation, Formal analysis, Investigation, Resources, Visualization, Writing – original draft, Writing – review and editing

• Authors: Melcon, M., Stern, E., Kessel, D., Arana, L., Poch, C., Campo, P., and Capilla, A.
• College/School: College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
• Journal Name: Psychophysiology
• Publisher: Wiley on behalf of Society for Psychophysiological Research
• ISSN: 0048-5772
• ISSN (Online): 1469-8986
• Published Online: 17 January 2024
• Copyright Holders: Copyright © 2024 The Authors
• First Published: First published in Psychophysiology 2024
• Publisher Policy: Reproduced under a Creative Commons licence