Pupil dilation in the Simon task as a marker of conflict processing

Area of Science:

• Cognitive Psychology
• Neuroscience
• Psychophysiology

Background:

• Cognitive conflict often leads to negative affect and avoidance behaviors.
• Previous research has yielded inconsistent results regarding physiological arousal, like pupil diameter, during conflict tasks.
• Null findings in prior studies may stem from methodological variations, such as the presence of light reflexes.

Purpose of the Study:

• To investigate the relationship between cognitive conflict and pupil dilation in a Simon task.
• To determine if pupil dilation can serve as a reliable physiological marker for conflict processing.
• To explore the influence of stimulus presentation (absence of light reflex) on pupil response to conflict.

Main Methods:

• Participants completed a Simon task designed to elicit response conflict.
• Pupil diameter was continuously monitored as a physiological index of arousal.
• Reaction times (RT) and pupil dilation were analyzed, including sequential analyses and single-trial regressions.

Main Results:

• Response conflict in the Simon task induced significant pupil dilation (approximately 0.02 mm) and increased reaction times.
• Pupil dilation exhibited a conflict-adaptation pattern mirroring that observed in reaction time.
• Single-trial analyses suggested pupil dilation reflects multiple underlying processes.

Conclusions:

• Pupil dilation can be reliably observed and measured in response to cognitive conflict during a Simon task, even without light reflexes.
• Pupil dilation serves as a valuable indirect marker for cognitive conflict processing.
• The findings contribute to understanding the psychophysiological correlates of conflict monitoring and adaptation.