Early alpha/beta oscillations reflect the formation of face-related expectations in the brain

Roehe M. A., Kluger D. S., Schroeder S. C. Y., Schliephake Lena M., Bölte J., Jacobsen Th., & Schubotz R. I.

Research article (journal)

Abstract

Although statistical regularities in the environment often go explicitly unnoticed, traces of implicit learning are evident in our neural activity. Recent perspectives have offered evi- dence that both pre-stimulus oscillations and peri-stimulus event-related potentials are reli- able biomarkers of implicit expectations arising from statistical learning. What remains ambiguous, however, is the origination and development of these implicit expectations. To address this lack of knowledge and determine the temporal constraints of expectation for- mation, pre-stimulus increases in alpha/beta power were investigated alongside a reduction in the N170 and a suppression in peri-/post-stimulus gamma power. Electroencephalogra- phy was acquired from naive participants who engaged in a gender classification task. Par- ticipants were uninformed, that eight face images were sorted into four reoccurring pairs which were pseudorandomly hidden amongst randomly occurring face images. We found a reduced N170 for statistically expected images at left parietal and temporo-parietal elec- trodes. Furthermore, enhanced gamma power following the presentation of random images emphasized the bottom-up processing of these arbitrary occurrences. In contrast, enhanced alpha/beta power was evident pre-stimulus for expected relative to random faces. A particu- larly interesting finding was the early onset of alpha/beta power enhancement which peaked immediately after the depiction of the predictive face. Hence, our findings propose an approximate timeframe throughout which consistent traces of enhanced alpha/beta power illustrate the early prioritisation of top-down processes to facilitate the development of implicitly cued face-related expectations.

Details zur Publikation

Release year: 2021
Language in which the publication is writtenEnglish