Task-independent and task-specific age effects on brain activity during working memory, visual attention and episodic...

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• The causes of age-related cognitive decline are debated, with theories proposing either a single common cause or multiple distinct factors.
• Understanding these causes is crucial for developing interventions to support cognitive health in aging populations.

Purpose of the Study:

• To investigate whether aging affects cognitive functions through common or distinct neural mechanisms.
• To examine age-related differences in brain activity across working memory, visual attention, and episodic retrieval tasks.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used to scan younger and older adults during three distinct cognitive tasks.
• Brain activity patterns, including regional activation and hemispheric engagement, were compared between the age groups.

Main Results:

• Older adults exhibited reduced occipital activity and increased prefrontal and parietal activity across tasks, suggesting sensory decline and compensatory mechanisms.
• Working memory and visual attention tasks revealed more bilateral prefrontal activation in older adults, aligning with the Hemispheric Asymmetry Reduction in Older Adults (HAROLD) model.
• While hippocampal formation activity decreased in older adults (suggesting a global effect), parahippocampal activity increased during episodic retrieval, indicating enhanced familiarity-based recognition.

Conclusions:

• Cognitive aging is influenced by a combination of common underlying factors and specific neural changes affecting different cognitive domains.
• The findings highlight the complexity of cognitive aging, involving both neural decline and adaptive compensatory strategies.