Weak neural signatures of spatial selective auditory attention in hearing-impaired listeners

Abstract

Spatial attention may be used to select target speech in one location while suppressing irrelevant speech in another. However, if perceptual resolution of spatial cues is weak, spatially focused attention may work poorly, leading to difficulty communicating in noisy settings. In electroencephalography (EEG), the distribution of alpha (8–14 Hz) power over parietal sensors reflects the spatial focus of attention [Banerjee, Snyder, Molholm, and Foxe (2011). J. Neurosci. 31, 9923–9932; Foxe and Snyder (2011). Front. Psychol. 2, 154.] If spatial attention is degraded, however, alpha may not be modulated across parietal sensors. A previously published behavioral and EEG study found that, compared to normal-hearing (NH) listeners, hearing-impaired (HI) listeners often had higher interaural time difference thresholds, worse performance when asked to report the content of an acoustic stream from a particular location, and weaker attentional modulation of neural responses evoked by sounds in a mixture [Dai, Best, and Shinn-Cunningham (2018). Proc. Natl. Acad. Sci. U. S. A. 115, E3286]. This study explored whether these same HI listeners also showed weaker alpha lateralization during the previously reported task. In NH listeners, hemispheric parietal alpha power was greater when the ipsilateral location was attended; this lateralization was stronger when competing melodies were separated by a larger spatial difference. In HI listeners, however, alpha was not lateralized across parietal sensors, consistent with a degraded ability to use spatial features to selectively attend.

Neural signatures of task-related fluctuations in auditory attention change with age

“…Consistent with previous reports, we show an age-related reduction of alpha activity in superior parietal cortex (Figure S2; Sander et al, 2012; Vaden et al, 2012; Deiber et al, 2013; Hong et al, 2015; Wöstmann et al, 2015; Henry et al, 2017; Leenders et al, 2018; Rogers et al, 2018; Bonacci et al, 2019; Getzmann et al, 2020), suggesting that parietal cortex is less involved in challenging attention tasks in older adults.…”

“…Older adults recruit different brain r Older adults recruit different brain r Older adults recruit different brain r Older adults recruit different brain regions for attention regulation than younger adults egions for attention regulation than younger adults egions for attention regulation than younger adults egions for attention regulation than younger adults Consistent with previous reports, we show an age-related reduction of alpha activity in superior parietal cortex (Figure S2; Sander et al, 2012;Vaden et al, 2012;Deiber et al, 2013;Hong et al, 2015;Wöstmann et al, 2015;Henry et al, 2017;Leenders et al, 2018;Rogers et al, 2018;Bonacci et al, 2019;Getzmann et al, 2020), suggesting that parietal cortex is less involved in challenging attention tasks in older adults.…”

“…In active listening tasks, alpha power typically increases relative to baseline (Wöstmann et al, 2015; Dimitrijevic et al, 2017; Henry et al, 2017), but older adults show weaker power increases (Wöstmann et al, 2015; Rogers et al, 2018) or even suppression of alpha power compared to younger individuals (Henry et al, 2017; Getzmann et al, 2020). Moreover, attention-related lateralization of alpha power in auditory spatial tasks appears to be reduced in older compared to younger adults (Getzmann et al, 2020) and in adults with hearing impairment compared to those without (Bonacci et al, 2019). However, from these works it is unclear whether dynamic attending to key points in time during challenging listening is affected by aging.…”

Poor early cortical differentiation of speech predicts perceptual difficulties of severely hearing-impaired listeners in multi-talker environments

“…Attention challenges remain despite the assistance of hearing aids 22 or cochlear implants (CIs) 23 , suggesting that rehabilitation is incomplete or that prostheses do not adequately address the challenges that listeners face in complex auditory environments. Neural correlates of selective attention are similarly affected; enhanced cortical tracking of attended talkers is reduced in both hearing-aided 24 and unaided impaired listeners 25 , and unaided hearing-impaired listeners show weaker lateralization of alpha power in spatial attention tasks 26 . Despite these differences, impaired listeners appear to perform selective attention tasks above chance (e.g., 25 ), suggesting that neural correlates of selective attention to some degree are still in operation.…”

Enhanced anticipatory biasing of visuospatial attention in deaf native-signing adults indexed by alpha-band (8-14 Hz) oscillatory neural activity

“…This finding implicates the engagement of a more extensive network in the parietal attention control system in deaf individuals, which may explain the enhancement in visuospatial attention abilities in deaf native signers, something that will need to be explicitly tested in future work. The potential repurposing of unused cortical regions typically associated with the modulation of audio-spatial attention may also explain the findings reported in Bonacci et al (2019), where alpha lateralization as a correlate of audio-spatial attention was explored. In participants with bilateral symmetric sensorineural hearing loss (at least 25 dB loss in the better ear), there was no significant alpha lateralization, unlike in hearing participants.…”