Functional brain correlates of response time variability in children

Area of Science:

• Neuroscience
• Developmental Psychology
• Cognitive Science

Background:

• Response time variability is linked to commission errors in response inhibition tasks.
• Higher variability suggests less consistent motor response preparation.
• Understanding neural correlates of variability is crucial for developmental disorders.

Purpose of the Study:

• To investigate the neural basis of intra-individual response time variability in children during a response inhibition task.
• To explore how brain activation differs between low and high response variability groups.
• To identify brain regions associated with consistent versus inconsistent performance in children.

Main Methods:

• Functional magnetic resonance imaging (fMRI) was used.
• A simplified Go/No-go task was administered to 30 typically developing children (ages 8-12).
• Analysis focused on brain activation patterns correlating with low and high response time variability.

Main Results:

• Lower variability correlated with activation in the anterior cerebellum (culmen) during Go trials and pre-SMA, postcentral gyrus, anterior cerebellum, and inferior parietal lobule during No-go trials.
• Higher variability was associated with activation in the prefrontal cortex and caudate for both Go and No-go events.
• These findings highlight distinct neural strategies for consistent and inconsistent response inhibition.

Conclusions:

• Children with lower response time variability rely on premotor circuits (e.g., pre-SMA) for response selection.
• Children with higher response time variability engage prefrontal circuits for more complex behavioral control.
• These neural differences have implications for understanding conditions like Attention-Deficit/Hyperactivity Disorder (ADHD).