Audiovisual dynamics in the alpha band: An examination of oscillations induced and intrinsic

Cunningham, Emily

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https://hdl.handle.net/2142/117551 Copy

Description

Title

Audiovisual dynamics in the alpha band: An examination of oscillations induced and intrinsic

Author(s)

Cunningham, Emily

Issue Date

2022-11-14

Director of Research (if dissertation) or Advisor (if thesis)

Beck, Diane

Doctoral Committee Chair(s)

Beck, Diane

Committee Member(s)

• Wang, Ranxiao F.
• Hummel, John E.
• Lleras, Alejandro
• Gratton, Gabriele

Department of Study

Psychology

Discipline

Psychology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• oscillation
• alpha
• entrainment
• audiovisual

Abstract

Posterior alpha rhythms are a particularly prominent feature of scalp-recorded EEG activity. Historically, the circuits that give rise to these 8-12 Hz patterns have largely been studied with respect to their relation to vision. Not only do these signals respond characteristically to visual stimulation and exhibit coincident effects associated with visual stimulus timing relative to ongoing activity—links have also been drawn between alpha circuit activity and visual selective attention. However, the dominance of visual characterizations of the alpha rhythm belies the fact that alpha rhythmic activity appears to emerge with similar dynamics across sensory modalities. As the discussion of alpha circuits and their relation to attention becomes increasingly cross-modal, questions begin to emerge about the degree to which previously-identified visual effects can be extrapolated across and between sensory modalities. Here, two such questions are examined. The series of experiments described in Chapter 2 evaluate whether the visual alpha signal, which appears to respond robustly to photic stimulation, can be manipulated by a cross-modal, auditory rhythm. These experiments provide behavioral evidence that visual alpha activity may be robust to extramodal (auditory) interference, although the effects of a visual rhythmic drive may be enhanced by the addition of auditory information. In Chapter 3, the focus is shifted from induced to intrinsic activity. Rather than examining the effects of rhythmic stimulation on performance, this chapter examines the relation between ongoing shifts in the alpha signal and detection of near-threshold stimuli when attention is directed to audition relative to vision. The aim of this work is to provide a detailed characterization of the relation between posterior alpha-band activity and performance as a function of attended modality. The results suggest that changes in the posterior alpha signal when attention is directed to audition relative to vision do not influence responses to auditory stimuli, and also provide evidence that previously identified changes in the alpha signal linked to threshold visual detection may be more broadband than oscillatory.

Graduation Semester

2022-12

Type of Resource

Thesis

Copyright and License Information

Copyright 2022 Emily Cunningham

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