Examining the effects of instant one-time caffeinated coffee consumption on cognitive performance of partially sleep-deprived university students with evening chronotype

Evening-chronotyped university students are commonly found in Hong Kong university campuses during late night. Despite previous literature studying the impacts of evening chronotype on college and university students, very few studies have examined the effects of instant one-time caffeinated coffee consumption on cognitive performance of partially sleep-deprived university students with evening chronotype. The main objective of this study is to compare the cognitive performance among partially sleep-deprived university students who have instantly one-time consumed caffeinated coffee and those who have not, in the areas of short-term memory capacity, information processing speed and arithmetic accuracy. Data for this research will come from experiment and questionnaire. Of the 36 university students, they will be arranged into three subject groups: (i) instantly one-time consuming caffeinated coffee, (ii) instantly one-time consuming decaffeinated coffee, and (iii) no instant coffee consumption, for conducting this study. For comparison of three cognitive variables of the aforementioned three subject groups, a three-way between-groups MANOVA will be run. It was found that there were statistically significance between two cognitive variables and subject groups, i.e. short-term memory capacity (p = .000) and information processing speed (p = .001), instead of arithmetic accuracy (p = .646). Cognitive performance, especially in short-term memory capacity and information processing speed, of partially sleep-deprived university students with evening chronotype is likely enhanced if they instantly one-time consume caffeinated coffee just 30 minutes before attending cognition-demanding tasks and learning activities, yielding a more favourable learning outcome.