Brain–environment synchrony and the auditory perception problem
Synchronization of brain rhythms to the rhythms of sounds is a foundational mechanism for auditory perception. However, we know very little about why brain–environment synchrony might fail, leading to auditory perception problems like impaired speech comprehension that negatively impact quality of life. The proposed research program fills this knowledge gap in three stages: 1) Predicting auditory perception, and individual differences thereof, from the fit between neural dynamics and environment; 2) Perturbing the relationship between brain and environment to experimentally test the limits of and protective factors for brain–environment synchronization; 3) Translating gained knowledge to understand age-related dysfunctions in brain–environment synchrony and auditory perception. Stage 1 uses behavioral and neural properties of neural oscillators – brain regions and networks that generate rhythmic neural activity – to predict individual differences in brain–environment synchronization. Stage 2 assesses when and why auditory perception fails, and how auditory perception might be insulated by good brain–environment fit and neural flexibility, by challenging the brain’s ability to adapt to auditory rhythms. Stage 2 has strong potential to provide insight into compensatory listening strategies that may be adopted when neural entrainment is effortful or impossible. Stage 3 places special emphasis on listening difficulties that develop with age, and tests the hypotheses that 1) speech comprehension difficulties stem from reduced neural entrainment in older age, and 2) reduced entrainment for older adults results from age-related changes to neural flexibility. Noninvasive brain stimulation will be used to temporarily remedy these deficits by improving brain–environment synchrony. The research program will account for much currently unexplained individual variance in auditory perception, and will inspire novel interventions to support auditory perception in advancing age.