Aging and Individual Variation in Interhemispheric Collaboration and Hemispheric Asymmetry.

Area of Science:

• Cognitive Neuroscience
• Human Aging Research
• Neuropsychology

Background:

• Investigating age-related changes in cognitive functions is crucial for understanding healthy aging.
• Interhemispheric interaction and hemispheric asymmetry are key aspects of brain function that may be affected by aging.

Purpose of the Study:

• To examine age-related changes in the efficiency of interhemispheric interaction.
• To assess age-related differences in hemispheric asymmetry.
• To explore the role of cognitive resources, such as memory span, in these age-related effects.

Main Methods:

• Participants: 30 younger adults (mean age 19.9) and 20 older adults (mean age 74.7).
• Tasks: Physical and Name Identity letter-matching tasks (within- and between-hemisphere conditions).
• Cognitive assessment: Memory span tasks to measure cognitive resources.

Main Results:

• Older adults experienced greater costs associated with interhemispheric collaboration than younger adults.
• In older adults, reduced memory span correlated with increased benefits from spreading processing across hemispheres.
• A left visual field/right hemisphere advantage was observed in younger, but not older, adults, suggesting age-related right-hemisphere decline.

Conclusions:

• Interhemispheric communication efficiency declines with age.
• Cognitive complexity modulates the benefits of bilateral processing in older adults.
• Evidence suggests greater age-related functional decline in the right hemisphere compared to the left.