Investigating task inhibition in children versus adults: A diffusion model analysis

Area of Science:

• Cognitive psychology
• Developmental psychology
• Neuroscience

Background:

• Task repetition costs, specifically n-2 costs, are used to measure inhibition at the task-set level.
• Performance costs arise when returning to a task (Task A) after one intermediate trial (ABA) compared to two or more (CBA), suggesting residual inhibition.

Purpose of the Study:

• To investigate age-related differences in inhibitory ability between children and young adults.
• To compare n-2 task repetition costs and the cognitive processes underlying task inhibition in these age groups.

Main Methods:

• Participants: 32 children (9-11 years) and 32 young adults (21-30 years).
• Task: Measured n-2 task repetition costs using ABA and CBA task sequences.
• Analysis: Compared mean reaction times and error rates; employed diffusion model analysis and Ex-Gaussian function fitting to reaction time distributions.

Main Results:

• No significant differences in mean reaction times or error rates between ABA and CBA sequences were observed between age groups.
• Diffusion model analysis indicated adults had a smaller drift rate in ABA vs. CBA (slower response selection), while children had longer non-decision times (longer task preparation).
• Ex-Gaussian analysis aligned with diffusion model findings, showing age-specific differences in distribution parameters (exponential for adults, Gaussian mu for children).

Conclusions:

• Despite similar behavioral costs, the cognitive mechanisms mediating task inhibition differ between children and adults.
• Adult task inhibition involves slower response selection, whereas child task inhibition may involve extended task preparation.
• These findings highlight developmental changes in the cognitive control of task switching and inhibition.