Aging is often associated with increased distractibility that may arise from a failure to adequately suppress the processing of irrelevant sensory information. In our recent Cerebral Cortex paper, we show that decreasing word intelligibility was associated with increasing visual cortex activity in younger, middle-aged, and older adults. In addition, age was related visual cortex activity: while younger adults suppressed visual cortex activity during listening, aging was associated with reduced suppression and increasing visual cortex activity. Our findings guide the prediction that both age and listening difficulty impact the likelihood that irrelevant sensory information will be distractible.Alternatively, this change could reflect the engagement of multi-sensory representations to help identify speech in difficult listening conditions.
Changes in auditory temporal processing are thought to be one reason why older adults have difficulty recognizing speech, especially in difficult listening conditions. Dr. Kelly Harris reports in the journal Hearing Research that changes in auditory temporal processing can be explained, in part, by changes in cognitive processing speed. Processing speed is the rate at which people can perform behavioral tasks and has been linked to brain regions important for directing attention. One potential implication of Dr. Harris’ findings is that age-related changes in speech recognition occur, in so far as they are related to auditory temporal processing, because of changes in brain regions important for directing attention.