Effect of caffeine on information processing: evidence from stroop task.

Background: Caffeine is a pyschostimulant present in various beverages and known to alter alertness and performance by acting on the central nervous system. Its effects on central nervous system have been studied using EEG, evoked potentials, fMRI, and neuropsychological tests. The Stroop task is a widely used tool in psychophysiology to understand the attention processes and is based on the principle that processing of two different kinds of information (like the word or colour) is parallel and at different speeds with a common response channel. Aim: To study the effect of caffeine on classical color word Stroop task. Materials and Methods: This study was conducted on 30 male undergraduate students by performing a test before and 40 minutes after consuming 3 mg/Kg caffeine and evaluating the effect of caffeine on Stroop interference and facilitation. Results: The results revealed that practice has no effect on the performance in a Stroop task. However, there was reduction in Stroop interference and increase in facilitation after consumption of caffeine as was evident by changes in the reaction times in response to neutral, incongruent, and congruent stimuli. Conclusion: We hypothesize that caffeine led to faster processing of relevant information.