The Interplay Between Tonic and Phasic Pupil Activity and Cognitive Flexibility and Stability.

Area of Science:

• Cognitive psychology
• Neuroscience
• Human behavior

Background:

• Phasic pupillary activity links to task performance and switch costs.
• Tonic pupillary activity is associated with exploration.
• The interplay between tonic and phasic pupillary activity in cognitive flexibility and stability remains under-investigated.

Purpose of the Study:

• To investigate the direct influence of tonic and phasic pupillary activity on cognitive flexibility and stability.
• To examine how pupillary responses relate to task switching and distractor inhibition.
• To explore individual differences in cognitive control modes.

Main Methods:

• Participants (n=51) completed a task with varying flexibility and stability demands, including ambiguous trials.
• Pupillary responses (phasic and tonic) were recorded during task performance.
• Behavioral data (switch costs, reaction times, error rates) were analyzed in relation to pupillary measures.

Main Results:

• Lower preference for switching correlated with higher switch costs and better performance on distractor inhibition, suggesting a stability-flexibility trade-off.
• Larger phasic pupillary responses in task-switching trials were linked to lower switch costs (higher flexibility).
• Greater tonic pupil diameter predicted lower flexibility preference, faster errors in cognitive stability tasks, and increased task disengagement.

Conclusions:

• Phasic pupillary activity is associated with cognitive flexibility, while tonic pupil diameter relates to cognitive stability and task engagement.
• Findings highlight distinct roles of tonic and phasic pupillary measures in cognitive control.
• Individual differences in pupillary activity may reflect stable versus flexible cognitive control strategies.