Understanding the Effects of Listening Effort on Sentence Processing and Memory in Sensorineural Hearing Loss: Evidence From Simultaneous Electrophysiology and Pupillometry (Study 2)
Trial Snapshot
- Phase
- Not Applicable
- Status
- Recruiting
- Sponsor
- University of Utah
- Enrollment
- 80
- Locations
- 2
- Primary Endpoint
- Delayed Recognition Memory
Study Overview
Brief Summary
Sensorineural hearing loss (SNHL) is among the most prevalent chronic conditions in aging and has a profoundly negative effect on speech comprehension, leading to increased social isolation, reduced quality of life, and increased risk for the development of dementia in older adulthood. Typical audiological tests and interventions, which focus on measuring and restoring audibility, do not explain the full range of cognitive difficulties that adults with hearing loss experience in speech comprehension. For example, adults with SNHL have to work disproportionally harder to decode acoustically degraded speech. That additional effort is thought to diminish shared executive and attentional resources for higher-level language processes, impacting subsequent comprehension and memory, even when speech is completely intelligible. This phenomenon has been referred to as listening effort (LE). There is a growing understanding that these cognitive factors are a critical and often "hidden effect" of hearing loss. At the same time, the effects of LE on the neural mechanisms of language processing and memory in SNHL are currently not well understood. In order to develop evidence-based assessments and interventions to improve comprehension and memory in SNHL, it is critical that the cognitive and neural mechanisms of LE and its consequences for speech comprehension are elucidated. In this project, the investigators adopt a multi-method approach, combining methods from clinical audiology, psycholinguistics, and cognitive neuroscience to address this gap of knowledge. Specifically, the investigators adopt a novel and innovative method of co-registering pupillometry (a reliable physiological measure of LE) and language-related event-related brain potential (ERP) measures during real-time speech processing to characterize the effects of clear speech (i.e., a listener-oriented speaking style that is spontaneously adopted to improve intelligibility when speakers are aware of a perception difficulty on behalf of the listener) on high-level language processes (e.g., semantic retrieval, syntactic integration) and subsequent speech memory in older adults with SNHL. This innovative work addresses a time-sensitive gap in the literature regarding the identification of objective and reliable markers of specific neurocognitive processes impacted by speech clarity and LE in age-related SNHL.
Detailed Description
This experiment is a Basic Experimental Study with Humans (BESH) Trial. All participants are exposed to all experimental conditions (i.e., "interventions") in a complete factorial 2 x 3 within-subjects experimental design. Participants will consist of 80 older adults between the ages of 60 - 90 who will be recruited from the Salt Lake metro community. Participants will be recruited through the Utah Senior Ears database, the Utah Center on Aging, through flyers placed throughout the community (e.g., bulletin boards, waiting area in the Ear Nose and Throat (ENT) clinic at the University of Utah), through on-line advertisements (e.g., Facebook) and via word-of-mouth. The investigators will recruit for an approximately equal number of participants into two hearing groups based on their pure-tone average (PTA) thresholds: normal hearing (PTA of < 25 decibels hearing level (dB HL), 1-4kHz) and clinically-relevant hearing loss (PTA of > 25 dBHL 1-4kHz). While this dichotomous grouping for recruitment is adopted, hearing level will be treated as continuous to increase statistical power.
The investigators will follow all American Psychological Association (APA) guidelines with respect to the treatment of human subjects. All participants will provide informed consent after study procedures are explained to them and the voluntary nature of participation will be emphasized. No identifying information (e.g., names) will be obtained from participants and the only information connected to their data files will be a unique, arbitrary code.
Study procedures will be conducted within a single session, lasting between 3-4 hours. Following informed consent, participants will complete a standardized hearing assessment, neuropsychological assessment, audibility control assessment, and then participant in the EEG/pupillometry experiment, each of which is described below. All data will be stored on password-protected computers in the PI's laboratory. All material from participants will be collected specifically for research purposes. The materials presented in these studies have no known potential to stress, embarrass, stigmatize, or incriminate experimental participants.
Prior to the beginning of the experiment, the investigators will conduct two audiometric tests via a Maico MA-41 audiometer via RadioEar IP-30 insert air-conduction earphones. First, pure-tone thresholds will be measured using the modified Hughson- Westlake at octave frequencies from 250 to 8000 Hz for each ear. Second, the investigators will test speech recognition thresholds (SRTs) using a recorded Central Institute for the Deaf (CID) W-1 spondee word list Near visual acuity was also tested for both the right and left eye using the Rosenbaum visual acuity test.
Participants will then complete a brief battery of cognitive assessments. (a) the Montreal Cognitive Assessment (MoCA). Although the appropriate cut-off score for cognitive impairment in the MoCA is variable across samples, individuals scoring below 20 are generally considered to be at increased risk for mild cognitive impairment (MCI). Therefore, the investigators use this as our conservative cut-off. Participants will also complete the F-A-S phonemic fluency task as a measure of verbal fluency, via the short- form computerized version of the reading span task as a measure of verbal working memory, and the extended range vocabulary tests from the Educational Testing Services Kit of Factor Referenced Cognitive Tests, as a measure of verbal ability. Participants will then complete an audibility control task. For this task, the same native speaker of American English will be used to record the stimuli at the same +3dB. Participants will hear nine different test sentences (e.g., "Don't touch the wet paint) and will be tasked with "shadowing" each sentence by repeating out loud each word as it was heard. The immediate repetition is done to reduce the contribution of any memory components to task performance.
Study Design
- Study Type
- Interventional
- Allocation
- Na
- Intervention Model
- Single Group
- Primary Purpose
- Basic Science
- Masking
- None
Masking Description
No masking -- participants are presented various stimuli in different experimental conditions.
Eligibility Criteria
- Ages
- 60 Years to 90 Years (Adult, Older Adult)
- Sex
- All
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •Age 60-90
- •Right-handed
- •Native English speaker
- •Scores in the normal range (> or = 25 points) on Montreal Cognitive Assessment (MoCA)
- •For adults with hearing loss, a pure-tone average score of > 25 dB HL (between 1 - 4kHz)
Exclusion Criteria
- •Left-handed (language-related electrophysiological responses of left-handed subjects differ from those of right-handed subjects)
- •History of psychiatric or neurological illnesses (including skull fractures, as this is known to alter electrophysiological response at the scalp)
- •Score of < 25 points on the MOCA
- •Use of certain prescription and non-prescription drugs known to alter brain function and the autonomic nervous system, including pupil dilation (e.g., anti-depressants, attention deficit hyperactivity disorder drugs)
- •Any eye disease that would impair the ability to measure pupil dilation (e.g., cataracts, nystagmus, amblyopia)
- •Scores on speech shadowing audibility control task below 50%, suggesting poor intelligibility
- •A display of behavior that would significantly interfere with the validity of data collection or safety during the study;
Outcomes
Primary Outcomes
Delayed Recognition Memory
Time Frame: Immediately after the speech listening portion of the experiment, up to 30 minutes.
Recognition memory will be measured using both standard accuracy and signal detection measures from the recognition memory task
P600 latency
Time Frame: During the speech listening portion of the experiment, up to 4 hours.
The P600 onset latency will be measured from the ERP waveform for each condition, using standard procedures.
N400 amplitude
Time Frame: During the speech listening portion of the experiment, up to 4 hours.
The N400 mean amplitude will be measured from the ERP waveform for each condition, using standard procedures for ERP research.
N400 latency
Time Frame: During the speech listening portion of the experiment, up to 4 hours.
The N400 onset latency will be measured from the ERP waveform for each condition, using standard procedures for ERP research.
P600 amplitude
Time Frame: During the speech listening portion of the experiment, up to 4 hours.
The P600 mean amplitude will be measured from the ERP waveform for each condition, using standard procedures.
pupil dilation
Time Frame: During the speech listening portion of the experiment, up to 4 hours.
The pupil dilation response (average proportion change from baseline) will be measured from the continuous pupillometry time series, measured prior to target word onset, and compared between speech samples presented in clear and conversational speech.
Secondary Outcomes
No secondary outcomes reported
Investigators
Brennan R Payne
Associate Professor of Psychology
University of Utah