Impact of Tea and Coffee Consumption on Cognitive Performance: An fNIRS and EDA Study

Abstract

Coffee and tea are two of the most popular beverages in the world and have been consumed for more than a thousand years. They have become an integral part of the day for many consumers and may aid not only increased social interactions but also productivity. However, there is no conclusive evidence of their comparative effect on cognitive ability. This study investigated the impact of tea and coffee products on cognitive performance in typical office work-related tasks using brain, body, and behavioral measures. In a controlled multi-day study, we explored the effects of both traditional and cognition-enhancing hot beverages through task performance and self-reported measures. A total of 120 participants completed three work-related tasks from different cognitive domains and consumed either a traditional or cognition-enhancing hot beverage. During the study, we measured brain activity in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS) as well as arousal from skin conductance through electrodermal activity (EDA) while participants completed cognitive tasks and consumed the beverages. Neural efficiency was used to evaluate cognitive performance in the tasks. Neural efficiency was calculated from a composite score of behavioral efficiency and cognitive effort, and emotional arousal was estimated from EDA activity. Results indicated that for different cognitive domains, the enhanced hot beverages showed improved neural efficiency over that of a traditional hot beverage. This is the first study to assess the impact of both traditional and cognition-enhancing drinks using a multimodal approach for workplace-related assignments.