Abstract

Auditory-cognitive associations in older adults: Differential effects of sex, test modality, and hearing measures

Faisal Al-Yawer, Ph.D.
Concordia University, 2022

This dissertation presents findings that address auditory-cognitive associations in older adults with hearing loss (HL), particularly with regards to sex-related differences in said associations.
Manuscript I (Chapter 2) reports the psychometric properties of the Montreal Cognitive Assessment scale (MoCA) when hearing-related items are excluded from scoring (MoCAModified). This involved a cross-sectional analysis of the original MoCA validation study data in healthy older adults, older adults with mild cognitive impairment (MCI), and older adults with mild Alzheimer’s disease (AD). Our findings showed that, compared to the original MoCA, MCI sensitivity was substantially reduced when all auditory subtests were omitted, with the biggest contribution to the reduction coming from the delayed recall subtest. This Chapter highlights the
contribution that hearing-dependent subtests have on the accuracy of the MoCA.
Manuscript II (Chapter 3) examines sex-related differences in the associations between MoCA scores and pure-tone average (PTA) in healthy older adults. MoCA-Modified scores were also
calculated for all participants to assess the contribution of hearing-dependent items. Results showed that women with normal hearing were more likely to pass the MoCA compared to their counterparts with HL. In contrast, no associations were observed in men. Regression analysis showed an interaction between sex and PTA in the worse ear. PTAs were significantly correlated with both MoCA and MoCA-Modified scores in women, but not in men. This suggests significant sex-related differences in auditory-cognitive associations even when hearing-related test items are omitted.
Manuscript III (Chapter 4) examines sex-related differences in auditory-cognitive associations in a sample of individuals with MCI. In this cross-sectional analysis, we examined sex-related
differences in hearing, as measured by both PTA and the Canadian Digit Triplet Test (CDTT), and cognition, as measured by the MoCA, Rey Auditory Verbal Learning (RAVLT), and the
Brief Visuospatial memory test (BVMT-R). Women with better hearing on either measure outperformed their worse hearing counterparts on the MoCA. Women with normal hearing
showed correlations between CDTT SRTs and MoCA and RAVLT scores. Men but not women showed an effect of hearing on the BVMT-R. Generally, this dissertation points to the existence of sex-related differences in auditory-cognitive associations and discusses potential mechanisms that underly these observations, including the common cause and information degradation hypotheses.