The Influence of Hearing Loss on Cognitive Control in an Auditory Conflict Task: Behavioral and Pupillometry Findings

The Effects of Noise and Simulated Conductive Hearing Loss on Physiological Response Measures During Interactive Conversations

PURPOSE

The purpose of this work was to study the effects of background noise and hearing attenuation associated with earplugs on three physiological measures, assumed to be markers of effort investment and arousal, during interactive communication.

METHOD

Twelve pairs of older people (average age of 63.2 years) with age-adjusted normal hearing took part in a face-to-face communication to solve a Diapix task. Communication was held in different levels of babble noise (0, 60, and 70 dBA) and with two levels of hearing attenuation (0 and 25 dB) in quiet. The physiological measures obtained included pupil size, heart rate variability, and skin conductance. In addition, subjective ratings of perceived communication success, frustration, and effort were obtained.

RESULTS

Ratings of perceived success, frustration, and effort confirmed that communication was more difficult in noise and with approximately 25-dB hearing attenuation and suggested that the implemented levels of noise and hearing attenuation resulted in comparable communication difficulties. Background noise at 70 dBA and hearing attenuation both led to an initial increase in pupil size (associated with effort), but only the effect of the background noise was sustained throughout the conversation. The 25-dB hearing attenuation led to a significant decrease of the high-frequency power of heart rate variability and a significant increase of skin conductance level, measured as the average z value of the electrodermal activity amplitude.

CONCLUSION

This study demonstrated that several physiological measures appear to be viable indicators of changing communication conditions, with pupillometry and cardiovascular as well as electrodermal measures potentially being markers of communication difficulty.

The impact of Alzheimer's disease risk factors on the pupillary light response

Alzheimer's disease (AD) is the leading cause of dementia, and its prevalence is increasing and is expected to continue to increase over the next few decades. Because of this, there is an urgent requirement to determine a way to diagnose the disease, and to target interventions to delay and ideally stop the onset of symptoms, specifically those impacting cognition and daily livelihood. The pupillary light response (PLR) is controlled by the sympathetic and parasympathetic branches of the autonomic nervous system, and impairments to the pupillary light response (PLR) have been related to AD. However, most of these studies that assess the PLR occur in patients who have already been diagnosed with AD, rather than those who are at a higher risk for the disease but without a diagnosis. Determining whether the PLR is similarly impaired in subjects before an AD diagnosis is made and before cognitive symptoms of the disease begin, is an important step before using the PLR as a diagnostic tool. Specifically, identifying whether the PLR is impaired in specific at-risk groups, considering both genetic and non-genetic risk factors, is imperative. It is possible that the PLR may be impaired in association with some risk factors but not others, potentially indicating different pathways to neurodegeneration that could be distinguished using PLR. In this work, we review the most common genetic and lifestyle-based risk factors for AD and identify established relationships between these risk factors and the PLR. The evidence here shows that many AD risk factors, including traumatic brain injury, ocular and intracranial hypertension, alcohol consumption, depression, and diabetes, are directly related to changes in the PLR. Other risk factors currently lack sufficient literature to make any conclusions relating directly to the PLR but have shown links to impairments in the parasympathetic nervous system; further research should be conducted in these risk factors and their relation to the PLR.

Exploring the Correlations Between Measures of Listening Effort in Adults and Children: A Systematic Review with Narrative Synthesis

Listening effort (LE) describes the cognitive resources needed to process an auditory message. Our understanding of this notion remains in its infancy, hindering our ability to appreciate how it impacts individuals with hearing impairment effectively. Despite the myriad of proposed measurement tools, a validated method remains elusive. This is complicated by the seeming lack of association between tools demonstrated via correlational analyses. This review aims to systematically review the literature relating to the correlational analyses between different measures of LE. Five databases were used- PubMed, Cochrane, EMBASE, PsychINFO, and CINAHL. The quality of the evidence was assessed using the GRADE criteria and risk of bias with ROBINS-I/GRADE tools. Each statistically significant analysis was classified using an approved system for medical correlations. The final analyses included 48 papers, equating to 274 correlational analyses, of which 99 reached statistical significance (36.1%). Within these results, the most prevalent classifications were poor or fair. Moreover, when moderate or very strong correlations were observed, they tended to be dependent on experimental conditions. The quality of evidence was graded as very low. These results show that measures of LE are poorly correlated and supports the multi-dimensional concept of LE. The lack of association may be explained by considering where each measure operates along the effort perception pathway. Moreover, the fragility of significant correlations to specific conditions further diminishes the hope of finding an all-encompassing tool. Therefore, it may be prudent to focus on capturing the consequences of LE rather than the notion itself.

Listen Carefully protocol: an exploratory case-control study of the association between listening effort and cognitive function

INTRODUCTION

A growing body of evidence suggests that hearing loss is a significant and potentially modifiable risk factor for cognitive impairment. Although the mechanisms underlying the associations between cognitive decline and hearing loss are unclear, listening effort has been posited as one of the mechanisms involved with cognitive decline in older age. To date, there has been a lack of research investigating this association, particularly among adults with mild cognitive impairment (MCI).

METHODS AND ANALYSIS

15-25 cognitively healthy participants and 15-25 patients with MCI (age 40-85 years) will be recruited to participate in an exploratory study investigating the association between cognitive functioning and listening effort. Both behavioural and objective measures of listening effort will be investigated. The sentence-final word identification and recall (SWIR) test will be administered with single talker non-intelligible speech background noise while monitoring pupil dilation. Evaluation of cognitive function will be carried out in a clinical setting using a battery of neuropsychological tests. This study is considered exploratory and proof of concept, with information taken to help decide the validity of larger-scale trials.

ETHICS AND DISSEMINATION

Written approval exemption was obtained by the Scientific Ethics Committee in the central region of Denmark (De Videnskabsetiske Komiteer i Region Hovedstaden), reference 19042404, and the project is registered pre-results at clinicaltrials.gov, reference NCT04593290, Protocol ID 19042404. Study results will be disseminated in peer-reviewed journals and conferences.

An Auditory Stroop Test to Implement in Cognitive Hearing Sciences: Development and Normative Data

Objective:

This study developed and gained insight in an auditory Stroop test, implementable in cognitive hearing sciences.

Methods:

An auditory Stroop test was developed and performed in 178 participants, aged between 18 and 69 years. This Auditory Stroop test consisted of two tests: Stroop-tones and Stroop-words whereby the pitch of pure-tones and spoken words (i.e., the words high and low) had to be identified by high or low, respectively. An interference score was calculated as a measure of verbal executive functioning. Regression models were conducted to examine the effect of age, sex, education, awakeness, hearing, as well as visual and verbal working memory, and processing speed on the auditory Stroop scores. Normative data were obtained per age decade.

Results:

Compared to the visual counterparts, the auditory Stroop outcomes were better predicted by verbal working memory and processing speed. A trend was observed showing a decrease in performances with increasing age. No other participant-related variables had a significant relationship with the auditory Stroop test.

Conclusion:

This auditory Stroop test was considered a good test for measuring executive functioning using auditory stimuli. Implementing this auditory Stroop test within cognitive hearing sciences will contribute to unravel the auditory-cognitive perspective of speech understanding.