Deficits in audiovisual speech perception in normal aging emerge at the level of whole-word recognition

NEUROBIOLOGY OF AGING

卷:36

Article

Stevenson, Ryan A.^1,2,3,4  Nelms, Caitlin E.^5,6  Baum, Sarah H.^3,7  Zurkovsky, Lilia⁸  Barense, Morgan D.^1,9  Newhouse, Paul A.⁸  Wallace, Mark T.^2,3,4,8,10 

[1] Univ Toronto, Dept Psychol, Toronto, ON M6G 3G3, Canada

[2] Vanderbilt Univ, Med Ctr, Dept Hearing & Speech Sci, Nashville, TN USA

[3] Vanderbilt Brain Inst, Nashville, TN USA

[4] Vanderbilt Kennedy Ctr, Nashville, TN USA

[5] Austin Peay State Univ, Dept Psychol, Clarksville, TN 37044 USA

[6] Univ Memphis, Dept Commun Sci & Disorders, Memphis, TN 38152 USA

[7] Univ Texas Med Sch Houston, Dept Neurobiol & Anat, Houston, TX USA

[8] Vanderbilt Univ, Dept Psychiat, Ctr Cognit Med, Nashville, TN 37235 USA

[9] Rotman Res Inst, Toronto, ON, Canada

[10] Vanderbilt Univ, Dept Psychol, Nashville, TN 37240 USA

关键词: Speech perception;    Multisensory;    Aging;    Multisensory integration;    Inverse effectiveness;   

DOI  :  10.1016/j.neurobiolaging.2014.08.003

来源: Elsevier

【 摘 要 】

Over the next 2 decades, a dramatic shift in the demographics of society will take place, with a rapid growth in the population of older adults. One of the most common complaints with healthy aging is a decreased ability to successfully perceive speech, particularly in noisy environments. In such noisy environments, the presence of visual speech cues (i. e., lip movements) provide striking benefits for speech perception and comprehension, but previous research suggests that older adults gain less from such audiovisual integration than their younger peers. To determine at what processing level these behavioral differences arise in healthy-aging populations, we administered a speech-in-noise task to younger and older adults. We compared the perceptual benefits of having speech information available in both the auditory and visual modalities and examined both phoneme and whole-word recognition across varying levels of signal-to-noise ratio. For whole-word recognition, older adults relative to younger adults showed greater multisensory gains at intermediate SNRs but reduced benefit at low SNRs. By contrast, at the phoneme level both younger and older adults showed approximately equivalent increases in multisensory gain as signal-to-noise ratio decreased. Collectively, the results provide important insights into both the similarities and differences in how older and younger adults integrate auditory and visual speech cues in noisy environments and help explain some of the conflicting findings in previous studies of multisensory speech perception in healthy aging. These novel findings suggest that audiovisual processing is intact at more elementary levels of speech perception in healthy-aging populations and that deficits begin to emerge only at the more complex word-recognition level of speech signals. (C) 2015 Elsevier Inc. All rights reserved.

【 授权许可】

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