Caffeine and iconic memory

Background: Research has examined the effects of caffeine on many aspects of memory. One area where there has been little research is sensory memory, and the present study examined the effects of caffeine on iconic memory (short-term visual memory). Methods: Participants (University students, N=24) completed a laboratory session in the morning or afternoon. Separate groups either received caffeine or a placebo. The caffeine dose was 4mg/kg and was carried out double-blind. The tasks involved either full or partial reports of a string of letters with varying inter-stimulus intervals (ISIs). Results: At baseline, the results were consistent with previous research, with recall performance in partial report conditions being superior to full report up to an ISI of 300 msec. There was no significant main effect of caffeine nor significant interactions between caffeine and report conditions. Conclusion: The results show that iconic memory is another aspect of memory that shows little effect of caffeine. Future research should use more sensitive tasks, such as those measuring semantic memory and executive functio