Assessing Changes in Visual Attention Secondary to Mild Hearing Loss in Aging through the Study of Response Time and Event-related Potentials
Year: 2019
Type: dissertation
Abstract: This set of studies was designed to evaluate the association between hearing loss in aging and extra-auditory cognitive decline by assessing younger normal-hearing adults (YN), and older adults with either age-typical hearing (ONHA) or mild hearing loss (OHL). A visual reaction time (RT) paradigm involving four tasks with hierarchically-varied attentional demands was administered with EEG. There were three main objectives. The first objective (Study 1) was to assess the effect of hearing loss on: i) RT, ii) error commission and recovery, and iii) strategic versus automatic response preparation. The OHL group demonstrated general slowing on the simplest tasks, less efficient error recovery, and difficulties with automatic response preparation, compared to both other groups. The second objective (Study 2) was to study the YN group’s EEG results using the N1 to identify the influence of task context on early attention-sensory evaluation and the scalp distribution of the P3 as a marker of attention guiding (anterior) and stimulus categorization and response preparation (posterior). The latency and amplitude of the N1, the posterior-anterior P3 amplitude distribution, and neural activity modeling supported an increasing reliance on anterior attentional processes as tasks required either an enhancement or suppression of attention for stimulus discrimination. The third objective (Study 3) was to compare the EEG data between the ONHA and OHL groups using the metrics used in Study 2. The OHL group had a longer N1 latency that correlated with their speeded visual executive test scores, longer anterior P3 latencies, hemispheric symmetry of N1 amplitudes indicative of less efficient top-down control, and anterior P3 amplitudes that indexed over-processing of unnecessary information. Latency and amplitude of the posterior P3 were comparable between both older groups. In sum, cognitively-intact older adults with mild hearing loss demonstrated differences in: i) response time on the simplest tasks and automatic preparatory processes compared to younger adults and older adults with age-typical hearing; and ii) ERP indices of sensory-cognition integration and early attentional guiding compared to older adults with age-typical hearing. These findings may represent mechanisms involving either localized differences in subcortical regions of sensory-motor-cognitive integration and/or disruptions of functional networks.
Source: TSpace (University of Toronto)
Author: Susan Gillingham
Language: English
Subfield: Speech and Hearing
Field: Health Professions
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W3153801615