Show simple item record

Effects of Aging on Cortical Representations of Continuous Speech

dc.contributor.advisorSimon, Jonathan Z.
dc.contributor.authorKarunathilake, I.M Dushyanthi
dc.descriptionMEG data were recorded while participants listen to 60-s-long passages. Data were analyzed using forward and backward modeling approaches known as temporal response functions (TRFs) and stimulus reconstruction accuracy respectively.en_US
dc.description.abstractUnderstanding speech in a noisy environment is crucial in day-to-day interactions, and yet becomes more challenging with age, even for healthy aging. Age-related changes in the neural mechanisms that enable speech-in-noise listening have been investigated previously; however, the extent to which age affects the timing and fidelity of encoding of target and interfering speech streams are not well understood. Using magnetoencephalography (MEG), we investigated how continuous speech is represented in auditory cortex in the presence of interfering speech, in younger and older adults. Cortical representations were obtained from neural responses that time-locked to the speech envelopes using speech envelope reconstruction and temporal response functions (TRFs). TRFs showed three prominent peaks corresponding to auditory cortical processing stages: early (~50 ms), middle (~100 ms) and late (~200 ms). Older adults showed exaggerated speech envelope representations compared to younger adults. Temporal analysis revealed both that the age-related exaggeration starts as early as ~50 ms, and that older adults needed a substantially longer integration time window to achieve their better reconstruction of the speech envelope. As expected, with increased speech masking, envelope reconstruction for the attended talker decreased and all three TRF peaks were delayed, with aging contributing additionally to the reduction. Interestingly, for older adults the late peak was delayed, suggesting that this late peak may receive contributions from multiple sources. Together these results suggest that there are several mechanisms at play compensating for age-related temporal processing deficits at several stages, but which are not able to fully reestablish unimpaired speech perception.en_US
dc.description.sponsorshipThis work was supported by grants from the National Institute on Aging (P01-AG055365) and the; National Institutes of Deafness and Other Communication Disorders (R01-DC014085, R01-DC019394).en_US
dc.rightsCC0 1.0 Universal*
dc.subjectspeech in noiseen_US
dc.titleEffects of Aging on Cortical Representations of Continuous Speechen_US
dc.relation.isAvailableAtA. James Clark School of Engineeringen_us
dc.relation.isAvailableAtElectrical & Computer Engineeringen_us
dc.relation.isAvailableAtDigital Repository at the University of Marylanden_us
dc.relation.isAvailableAtUniversity of Maryland (College Park, MD)en_us

Files in this item


This item appears in the following Collection(s)

Show simple item record

CC0 1.0 Universal
Except where otherwise noted, this item's license is described as CC0 1.0 Universal