Dissociable Effects of Aging and Mild Cognitive Impairment on Bottom-Up Audiovisual Integration
Autor: | Brian R. Ott, William C. Heindel, Elena K. Festa, Geoffrey Tremont, Andrew P. Katz |
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Rok vydání: | 2017 |
Předmět: |
Male
Aging medicine.medical_specialty Sensory system Neuropsychological Tests Stimulus (physiology) Audiology 050105 experimental psychology Perceptual Disorders Young Adult 03 medical and health sciences 0302 clinical medicine Cognitive change medicine Humans Cognitive Dysfunction 0501 psychology and cognitive sciences Cognitive impairment Aged Analysis of Variance General Neuroscience 05 social sciences Multisensory integration General Medicine Superior temporal sulcus Primary sensory areas Psychiatry and Mental health Clinical Psychology medicine.anatomical_structure Acoustic Stimulation Auditory Perception Visual Perception Female McGurk effect Geriatrics and Gerontology Psychology Photic Stimulation 030217 neurology & neurosurgery |
Zdroj: | Journal of Alzheimer's Disease. 59:155-167 |
ISSN: | 1875-8908 1387-2877 |
Popis: | Effective audiovisual sensory integration involves dynamic changes in functional connectivity between superior temporal sulcus and primary sensory areas. This study examined whether disrupted connectivity in early Alzheimer's disease (AD) produces impaired audiovisual integration under conditions requiring greater corticocortical interactions. Audiovisual speech integration was examined in healthy young adult controls (YC), healthy elderly controls (EC), and patients with amnestic mild cognitive impairment (MCI) using McGurk-type stimuli (providing either congruent or incongruent audiovisual speech information) under conditions differing in the strength of bottom-up support and the degree of top-down lexical asymmetry. All groups accurately identified auditory speech under congruent audiovisual conditions, and displayed high levels of visual bias under strong bottom-up incongruent conditions. Under weak bottom-up incongruent conditions, however, EC and amnestic MCI groups displayed opposite patterns of performance, with enhanced visual bias in the EC group and reduced visual bias in the MCI group relative to the YC group. Moreover, there was no overlap between the EC and MCI groups in individual visual bias scores reflecting the change in audiovisual integration from the strong to the weak stimulus conditions. Top-down lexicality influences on visual biasing were observed only in the MCI patients under weaker bottom-up conditions. Results support a deficit in bottom-up audiovisual integration in early AD attributable to disruptions in corticocortical connectivity. Given that this deficit is not simply an exacerbation of changes associated with healthy aging, tests of audiovisual speech integration may serve as sensitive and specific markers of the earliest cognitive change associated with AD. |
Databáze: | OpenAIRE |
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