Generalizing the disuse hypothesis: age-related sensory decline in the modality of communication leads to poorer episodic memory but preserved working memory
Description: Explicit working memory processing comes into play when speech communication takes place under adverse conditions, for example in background noise or when one of the communicating parties has a hearing impairment. Age-related hearing loss is associated with age-related cognitive decline and temporal lobe atrophy. In particular, the effect of hearing loss strikes at episodic memory more than working memory, while no such effect is found for visual loss in hearing individuals. It has been suggested that while hearing loss keeps working memory in trim by requiring continual activation in communicative situations, episodic memory declines because of disuse.
Profoundly deaf individuals often prefer sign language communication, even when they use technical aids such as cochlear implants (CI) to access acoustic information. This applies especially in noise, where the CI is ineffective because it cannot separate signal from noise. Acoustically noisy situations are often visually noisy, i.e. the visual signal may be degraded in various ways, and it is likely that explicit working memory capacity comes into play during sign language communication in such adverse conditions. Thus, congenitally profoundly deaf sign language users without CI can help us test the theory that age-related sensory loss in preferred modality of communication drives episodic memory decline, under the disuse hypothesis. Support for the theory will be obtained if visual loss is associated with greater age-related decline in episodic memory than in working memory in this group.
Videogaming enhances cognition in both younger and older hearing adults, potentially counteracting the effects of age-related sensory decline on memory systems. However, it is not known whether videogaming enhances cognition in deaf individuals, who use visual (sign) language.
The proposed project constitutes the first two testing phases in a longitudinal study, which as the first scientific investigation of its kind, will examine:
1. how visual noise influences working memory for sign language and the neural networks that support it
2. how sensory loss, sign language knowledge and videogaming experience influence the dynamic relation between episodic and working memory
The overarching goal of the project is to test whether current memory models are neurocognitively robust across the modalities of sign and speech. It will generate knowledge that can be applied in hearing rehabilitation, design of the built environment and digital communication interfaces.
Funder: Vetenskapsrådet
Amount: SEK 3,585,000
Funding type: research
Funder scheme: Project grant
Start date: 2016-01-01
End date: 2020-12-31
Investigator: Emil Holmer
Institution: Linköping University
Funded outputs count: 5
Funder award ID: 2015-00929
OpenAlex ID: G5449348381