Pupillary response like physiological marker in the decisions making

Key words: Pupil diameter, decision making, Stroop.

Behavioral neuroscience usually has dealt with autonomic arousal in terms of struggle for survival or intense emotion. However, many recent studies have indicated that cognitive efforts are associated with autonomic arousal. Thus, this activation could be necessary to perform some cognitive task and decision making. However this relationship remains poorly understood.
The aim of this study was to relate the pupil diameter with decision making using an eye tracker in a special version of the Stroop task. In this paradigm the subjects have to classify word stimuli according to font size and meaning as either big or small by button press responses, we use trials where the size and meaning were different (semantically incongruent) and words where meaning corresponded to the current print size value (semantically congruent). The participants were twelve, healthy and right handed young adults, who performed a variant of the Stroop task, when they answered we recorded the pupil activity in the different conditions. The variation of the pupil diameter was significantly greater after incongruent than congruent stimuli. Furthermore the pupil changes were greater when responses were incorrect. The results suggest that autonomic arousal occurs during cognitive conflict resolution. This research provides evidence about the importance of consider physiological markers, like the pupil, in decisions making. Furthermore this finding is important because allow correlate the autonomic response and cognitive processes.