Characterizing the roles of alpha and theta oscillations in multisensory attention

Abstract

Cortical alpha oscillations (8–13 Hz) appear to play a role in suppressing distractions when just one sensory modality is being attended, but do they also contribute when attention is distributed over multiple sensory modalities? For an answer, we examined cortical oscillations in human subjects who were dividing attention between auditory and visual sequences. In Experiment 1, subjects performed an oddball task with auditory, visual, or simultaneous audiovisual sequences in separate blocks, while the electroencephalogram was recorded using high-density scalp electrodes. Alpha oscillations were present continuously over posterior regions while subjects were attending to auditory sequences. This supports the idea that the brain suppresses processing of visual input in order to advantage auditory processing. During a divided-attention audiovisual condition, an oddball (a rare, unusual stimulus) occurred in either the auditory or the visual domain, requiring that attention be divided between the two modalities. Fronto-central theta band (4–7 Hz) activity was strongest in this audiovisual condition, when subjects monitored auditory and visual sequences simultaneously. Theta oscillations have been associated with both attention and with short-term memory. Experiment 2 sought to distinguish these possible roles of fronto-central theta activity during multisensory divided attention. Using a modified version of the oddball task from Experiment 1, Experiment 2 showed that differences in theta power among conditions were independent of short-term memory load. Ruling out theta’s association with short-term memory, we conclude that fronto-central theta activity is likely a marker of multisensory divided attention.

Relative Average Look Duration and its Association with Neurophysiological Activity in Young Children with Autism Spectrum Disorder

“…For TD children, as average look duration to social stimuli relative to toys increased, central and posterior EEG theta power while viewing social versus toy stimuli also increased. This is consistent with previous studies that have found that frontal theta band activity increases when individuals pay attention to multi-sensory stimuli involving auditory and visual input 56 , particularly since the social stimuli were more complex (e.g., involving language) than the dynamic toy stimuli. Furthermore, reduced frontal beta power while viewing social versus toy stimuli was associated with increased attention duration to the social relative to the nonsocial video.…”

Content-Free Awareness: EEG-fcMRI Correlates of Consciousness as Such in an Expert Meditator

“…Latest findings from research in REM sleep and ketamine anesthesia suggest that a decrease in alpha power may be a marker for a disconnection of consciousness from sensory stimuli (Sanders et al, 2012;Darracq et al, 2018;Comsa et al, 2019). Increases in theta power have been found to be associated with cognitive control and stable attention (Cavanagh and Frank, 2014;Keller et al, 2017) as well as with decreased activity in the DMN (White et al, 2013;Hacker et al, 2017), which is related to self-processing and mind-wandering.…”

“…Similar to alpha power, theta power was found to be associated with cognitive control (Başar et al, 2001;Cavanagh and Frank, 2014) and attention (Keller et al, 2017). Increases in frontal midline theta power have been found across a variety of meditation practices (Cahn and Polich, 2006;Lomas et al, 2015) and especially during concentrative meditation (Baijal and Srinivasan, 2010;Aftanas and Golocheikine, 2014).…”

Increased Functional Brain Network Efficiency During Audiovisual Temporal Asynchrony Integration Task in Aging

“…We found that multisensory attention led to decreased lower-frequency theta and alpha activity in early sensory cortex areas and to increased low-frequency phase synchronization in the frontal cortex ( Friese et al, 2016 ). The theta band appears to be predominantly implicated in cognitive control and short-term memory in audiovisual integration ( Demiralp and Başar, 1992 ; Sakowitz et al, 2000 ; Keller et al, 2017 ), while the alpha band seems to be mainly related to the maintenance of sensory information, cognitive control and the suppression of distractions ( Masahiro et al, 2010 ; Başar, 2012 ). Recently, van Driel et al (2014) determined the functional role of the coupling of alpha phase dynamics between sensory cortices in integrating cross-modal information over time.…”