Working memory in older subjects: dealing with ongoing and stored information in language comprehension

Area of Science:

• Cognitive Psychology
• Neuroscience of Aging
• Human Language Processing

Background:

• Working memory (WM) is crucial for language comprehension, involving both information processing and storage.
• Aging may impact the dual functions of WM, affecting cognitive performance in older adults.
• Understanding age-related changes in WM is vital for explaining difficulties in complex cognitive tasks like language comprehension.

Purpose of the Study:

• To investigate how aging affects the dual functions of working memory (processing and storage) during language comprehension.
• To examine the impact of increased processing difficulty and mnemonic load on young and older adults' performance.

Main Methods:

• Participants (young and older adults) performed a dual-task assessing incongruity detection in sentences and word-list recall.
• Incongruity detection difficulty was manipulated by varying the number of intervening words.
• Concurrent mnemonic load was increased by using longer word series (3, 4, or 5 words).

Main Results:

• Older adults showed a greater accuracy decrement than young adults when incongruity detection difficulty increased, indicating impaired information processing.
• Older adults exhibited a slightly smaller accuracy decrement under increased mnemonic load, but recalled fewer words, suggesting a shift in resource allocation.
• Older subjects tended to prioritize immediate information processing over storing recently processed material.

Conclusions:

• Aging impairs the information-processing function of working memory, particularly under demanding conditions.
• Older adults may sacrifice memory storage to cope with simultaneous processing demands in language comprehension tasks.
• These findings highlight age-related differences in working memory resource allocation and have implications for understanding language comprehension in aging.