Right anterior cerebellum BOLD responses reflect age related changes in Simon task sequential effects

Area of Science:

• Cognitive neuroscience
• Neuroimaging
• Human behavior

Background:

• The Simon task reveals that irrelevant stimulus location interferes with response selection.
• This congruency effect is amplified in older adults.
• Sequential effects, influenced by inter-trial intervals, can normalize performance in older adults.

Purpose of the Study:

• To investigate the neural mechanisms underlying age-related changes in the Simon task.
• To compare brain activity (BOLD signals) in young and older adults during a visual Simon task.
• To explore the role of the cerebellum in age-related differences in sequential effects.

Main Methods:

• Functional magnetic resonance imaging (fMRI) to measure blood-oxygen-level-dependent (BOLD) signals.
• Comparison of BOLD responses between young and older adult participants performing a visual Simon task.
• Analysis of BOLD signals in relation to target congruency and preceding trial congruency.

Main Results:

• Older adults exhibited delayed and lower amplitude BOLD responses compared to young adults.
• BOLD responses in visual and motor regions were modulated by previous trial congruency in both age groups.
• Young adults showed differential cerebellar BOLD responses based on current and previous trial congruency, unlike older adults.

Conclusions:

• Aging may impair the updating of stimulus-location-to-response mappings, a process linked to sequential effects.
• The anterior cerebellum appears crucial for trial-by-trial updating of these mappings during the inter-trial interval.
• Age-related decline in cerebellar function may underlie the observed difficulties in cognitive control within the Simon task.