Congratulations to Viji Easwar, Ph.D., FAAA, on receiving a 2018 American Speech-Language-Hearing Foundation New Investigator Research Grant for her project “Short- and Long-term Influence of Context on Vowel-evoked Envelope Following Responses”.
Envelope following responses (EFRs) are scalp-recorded neural responses phase-locked to the periodicity in sounds like vowels. Evaluating the effect of context in vowel-evoked EFRs is important because EFRs are often elicited by vowels embedded between consonants to maintain the syllabic structure of speech. The effect of preceding context on perception has been widely acknowledged. However, the influence of the preceding context on the EFRs evoked by vowels is unknown. In the proposed project, we aim to evaluate the short- and long-term influence of context in two experiments. In the first experiment, we will evaluate the effect of level and spectra of the preceding context on EFRs evoked by the cardinal vowel /i/. In the second experiment, we will evaluate the variability in /i/-evoked EFR amplitude when predictability of the preceding context is altered. Using single-channel electro-encephalographic measurements from 23 young adults with normal hearing, we expect to (a) determine the need to consider the preceding context while interpreting vowel-evoked EFRs, and (b) quantify the degree of habituation-related attenuation in EFR amplitude due to the use of predictable contexts. Together, findings will guide interpretation and optimization of future EFR test paradigms for clinical and research use.
The New Investigators Research Grant supports research activities of new investigators who have earned their doctorate degree within the past five years.