Hearing Loss In Older Adults May Compromise Cognitive Resources For Memory

The study, published in the latest issue of Current Directions inPsychological Science, showed that even when older adults could hearwords well enough to repeat them, their ability to memorize andremember these words was poorer in comparison to other individuals ofthe same age with good hearing.

"There are subtle effects of hearing loss on memory and cognitivefunction in older adults," said lead author Arthur Wingfield, NancyLurie Marks Professor of Neuroscience at the Volen National Center forComplex Systems at Brandeis University. "The effect of expending extraeffort comprehending words means there are fewer cognitive resourcesfor higher level comprehension."

"This extra effort in the initial stages of speech perception usesprocessing resources that would otherwise be available for downstreamoperations, such as encoding the material in memory or performinghigher-level comprehension operations," explained co-authors PatriciaA. Tun and Sandra L. McCoy.

A group of older adults with good hearing and a group withmild-to-moderate hearing loss participated in the study. Eachparticipant listened to a fifteen-word list and was asked to rememberonly the last three words. All words were delivered at the same volume.Both groups showed excellent recall for the final word, but thehearing-loss group displayed poorer recall of the two words precedingit.

Because both groups could correctly report the final word, it wasreasoned that the hearing-loss group's failure to remember the othertwo words was not a result of their inability to hear/correctlyidentify them. The authors interpret this as a demonstration of theeffortfulness principle-- the increased effort required detracted fromthe cognitive processes of memorizing these words.

"This study is a wake-up call to anyone who works with older people,including health care professionals, to be especially sensitive to howhearing loss can affect cognitive function," said Dr. Wingfield.

He suggested that individuals who interact with older people with somehearing loss could modify how they speak by speaking clearly andpausing after clauses, or chunks of meaning, not necessarily slowingdown speech dramatically.

Current Directions in Psychological Science, a journal of the AmericanPsychological Society, presents the latest advances in theory andresearch in psychology. This important and timely journal containsconcise reviews spanning all of scientific psychology and itsapplications.

The American Psychological Society represents psychologists advocating science-based research in the public's interest. www.psychologicalscience.org

Over the last 15 years Dr. Wingfield and Dr. Tun have carried outextensive programs of research, funded by National Institute on Aging,studying effects of aging on speech processing and memory for spokenlanguage. More recently they have focused on effects of mild tomoderate hearing loss, and how sensory changes interact withcomprehension and memory for speech in younger and older adults.