Examining the Impact of Hearing Impairment on Neural Patterns in Spatial Attentional Filtering

Authors: Nataliya Fartdinova1, Mohsen Alavash2, Tzvetan Popov1, Malte Wöstmann2, Jonas Obleser2, Basil Preisig1

1University of Zurich
2University of Lübeck

Background: Individuals with hearing loss (HL) face challenges in focusing on a single speaker while ignoring background noises and multiple talkers in crowded environments. These challenges may be associated with the inefficient neural filtering mechanisms such as target selection and distractor suppression. In a recent study, our collaborators were able to demonstrate that alpha oscillations in the human brain implement distractor suppression independent of target selection by placing a target stimulus in front of the listener and a distractor either on the left or the right, and vice versa. The objective of this preregistered study is to examine the impact of HL on these attentional subprocesses.

Method: Normal-hearing (NH) young and elderly participants, along with elderly individuals experiencing HL perform a pitch discrimination task using electroencephalography (EEG). The task ensures spatial separation between the target and distractor, enabling to identify changes in neural alpha activity (around 8-12 Hz), indicative of attended and ignored speech.

Results: The interim state of analysis shows dissociable alpha modulation patterns for lateral target selection and lateral distractor suppression in elderly individuals with and without HL. Lateral target selection exhibits stronger alpha modulation in the ipsilateral hemisphere compared to the contralateral hemisphere, whereas the opposite pattern is observed for lateral suppression (see attached figure). At the current state of analysis, there is no evidence for a systematic difference in these modulation patterns across young, elderly, and elderly individuals with HL.

Conclusion: The existing findings do not indicate an ‘inefficient neural filtering’ in older individuals and those with HL.