A right‐ear bias of auditory selective attention is evident in alpha oscillations

Abstract

Auditory selective attention makes it possible to pick out one speech stream that is embedded in a multi-speaker environment. We adapted a cued dichotic listening task to examine suppression of a speech stream lateralized to the non-attended ear, and to evaluate the effects of attention on the right ear's well-known advantage in the perception of linguistic stimuli. After being cued to attend to input from either their left or right ear, participants heard two different four-word streams presented simultaneously to the separate ears. Following each dichotic presentation, participants judged whether a spoken probe word had been in the attended ear's stream. We used EEG signals to track participants' spatial lateralization of auditory attention, which is marked by inter-hemispheric differences in EEG alpha (8-14 Hz) power. A right-ear advantage (REA) was evident in faster response times and greater sensitivity in distinguishing attended from unattended words. Consistent with the REA, we found strongest parietal and right fronto-temporal alpha modulation during the attend-right condition. These findings provide evidence for a link between selective attention and the REA during directed dichotic listening.

Older adults show impaired modulation of attentional alpha oscillations: Evidence from dichotic listening.

“…Payne et al (2016) found that young adults’ successful filtering of unattended speech was concurrent with modulation of power in the alpha band during encoding. Alpha modulation was found at two different locations, a right lateral frontotemporal and a central parietal site.…”

“…Listening in such situations is notoriously more difficult and more poorly encoded to long-term memory in older than in young adults (Tun, O’Kane, & Wingfield, 2002). Recent work by Payne, Rogers, Wingfield, and Sekuler (2016) in young adults demonstrated a neural correlate of auditory attention in the directed dichotic listening task (DDLT), where listeners attend to one ear while ignoring the other. Measured using electroencephalography (EEG), differences in alpha band power (8–14 Hz) between left and right hemisphere parietal regions mark the direction to which auditory attention is focused.…”

“…Using a form of the DDLT task, Payne et al (2016) presented young adults with recognition probes and asked them to indicate whether the probe was presented in the to-be-attended ear. Perceptual dampening of irrelevant perceptual stimuli is known to be correlated with alpha-band activity measured via electroencephalography (EEG; Payne & Sekuler, 2014).…”

“…In addition to our focus on age-related effects pertaining to alpha power and modulation during encoding of dichotically presented stimuli, we were also interested in how short-term recognition probes during the DDLT would evoke responses from the brains of young and older adults. As reported by Danker et al (2008), and others (for a review, see Rugg, 1995), recently presented words evoke more positive event-related potentials (ERPs) than new words, an effect that has been termed the “ERP old-new effect.” The DDLT utilized by Payne et al (2016) is a short-term recognition task, although probes have the additional categorization of being “new,” “attended,” or “unattended,” as opposed to simply “old” and “new.” In this task, participants report “yes” or “no” as to whether the probe was presented in the to-be-attended channel. Little work has examined the extent to which attending to or ignoring a word during dichotic encoding affects ERPs.…”

Influence of Audiovisual Training on Horizontal Sound Localization and Its Related ERP Response

“…For sound localization (Test 0), participants would hear signals from 13 directions (0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165, 180°) and they were required to perceive the direction and indicate it with a laser pointer. Considering the facts of so-called “right ear advantage” and dominance for temporal processing of left hemisphere, together with people’s preference when perceiving the auditory stimuli (Hall et al, 2002 ; Richter et al, 2013 ; Payne et al, 2017 ; Tai and Husain, 2018 ), only right-side sounds were used in the experiment, as shown in Figures 2A,B . In the localization test, to verify the participants was able to localize accurately, participants were asked to indicate the directions until they were confident that they had point to the direction as accurately as possible.…”