1. How Caffeine Affects Multitasking
Lacey Caparanis, Kurt Fire, Angela Shrader, and Jiaer Su
Faculty Advisor: Dr. Christopher Klein
Marietta College
Abstract
This study focused on the effects of caffeine on
multitasking ability. In this study, participants were asked to
consume either a cup of caffeinated coffee or a cup of
decaffeinated coffee. The researchers randomly assigned
participants to one of four groups: one group that received
caffeinated coffee was told it was caffeinated, the other was
told it was decaffeinated; one group that received
decaffeinated coffee was told decaffeinated, and the other
was told caffeinated. Participants then had a waiting period
of 20 minutes before the multitasking portion of the study
began. The multitasking portion consisted of a computer
program, called the Operation Span Task (OSPAN) and a
listening task. Participants completed the math test while
simultaneously listening to the recorded reading. After the
multitasking task was finished, the participant completed a
quiz over the recorded reading. Results suggest that no
significant relation existed between caffeine intake and
multitasking.
Introduction
Materials
This study required the use of a computer program which allowed the
participants to perform simple math problems in an allotted amount of
time. Each question was presented for no more than five seconds.
Upon answering, the program alerted the participant of either an correct
or incorrect question and continue to the next equation. The data from
the program results was recorded. The program served as one of the
tasks in the multitasking behavior.
Procedure
Results
 Adan, A., & Serra-Grabulosa, J. (2010). Effects of
caffeine and glucose, alone and combined, on cognitive
performance. Human Psychopharmacology: Clinical
and Experimental, 25, 310-317. doi: 10.1002/hup.1115
 Bowman, L. L., Levine, L. E., Waite, B. M., & Gendron, M.
(2010). Can students really multitask? An experimental
study of instant messaging while reading. Computers &
Education, 54, 927-931. doi:
10.1016/j.compedu.2009.09.024
 Lorist, M. M., & Tops, M. (2003). Caffeine, fatigue, and
cognition. Brain and Cognition, 53, 82-94. doi:
10.1016/S0278-2626(03)00206-9
 Ruijter, J., Lorist, M., Snel, J., & De Ruiter, M. B. (2000).
The influence of caffeine on sustained attention: An
ERP study. Pharmacology Biochemistry and Behavior,
66, 29-37. doi: S0091-3057(00)00229-X
 In an experiment by Lorist and Tops (2003), a low dose of
caffeine (50-300mg) was able to enhance performance;
however, higher doses showed no benefits or decrease in
performance.
 An ERP study also suggested that caffeine did not cause
improvement on participants’ performance of sustained
attention. The results suggested that the caffeine did not
improve the participants’ abilities to complete the task,
but the groups did differ in brain activity (Ruijter, Lorist,
Snel, & De Ruiter, 2000).
 Other research concluded that caffeine and glucose
increased attention, but there is still a lack of research
that primarily focuses on the direct effect of caffeine on
multitasking situations (Adan et al., 2010)
 Bowman, Levine, Waite, and Gendron (2010) developed a
study that showed that the participants who answered
instant messages during the reading took longer to finish
the task, but scored equally as well on a test as the other
groups who were not completing two tasks
simultaneously, which suggests that multitasking harmed
students’ abilities to successfully complete two tasks at
once.
 The question of interest was whether or not participants
could remain attentive on more than one task and
simultaneously retain information while under the
influence of caffeine. The hypothesis of this study was
that ingesting caffeine would have a significant effect on
one’s ability to multitask.
Tables & Graphs
References
Participants
Participants were chosen from students enrolled in psychology classes from Marietta College and received class credit for
participation in the study. The average age of the participants were 18-22 years. Participants were randomly assigned to one of
three experimental conditions: told caffeinated, given caffeinated coffee; told caffeinated, given decaffeinated coffee; told
decaffeinated, given decaffeinated coffee; or told decaffeinated, given caffeinated coffee.
Current Study
 Participants were asked to read and sign a health form and an informed consent form, and were then administered one of four
different treatments: told caffeinated, given caffeinated coffee; told caffeinated, given decaffeinated coffee; told decaffeinated,
given decaffeinated coffee; or told decaffeinated, given caffeinated coffee.
 Participants were then given a demographic form to complete, and then had a waiting period of 20 minutes.
 They were then instructed to complete the Operation Span Task (OSPAN), while paying as close attention as possible to an audio
clip being played on a laptop located adjacent to the computer. The audio clip, roughly 25 minutes long, was a selected segment
read from the book The Professor and the Madman by Simon Winchester.
 At the conclusion of the audio clip, participants were given another short quiz regarding details presented in the audio clip.
 After the questionnaire was completed, participants were debriefed and told the true nature of the study.
0 20 40 60 80 100
Told Caffeine, Given Caffeine
Told Caffeine, Given Decaf
Told Decaf, Given Caffeine
Told Decaf, Given Decaf
Average Score on OSPAN Task
3.8 3.9 4 4.1 4.2 4.3 4.4
Told Caffeine, Given Caffeine
Told Caffeine, Given Decaf
Told Decaf, Given Caffeine
Told Decaf, Given Decaf
Average Score on Reading Comprehension
Quiz
Using a one-way Analysis of Variance (ANOVA) test, we found no significant effect of condition on either the OSPAN task
(F(3,8)=1.36, p=.32) and reading test (F(3,8)=.06, p=.98) scores.
There was no significant difference in performance between participants given caffeine and participants not given caffeine on either the
OSPAN task or the reading comprehension quiz.
These results are consistent with Rujiter et al.’s (2000) study that found no significant correlation between caffeine and sustained
attention.
Future research should investigate whether the amount of time the participant takes to consume the coffee changes the effect of
the caffeine, as well address the question of perceived effects of caffeine on multitasking ability. Future research could also
explore various multitasking conditions.
Potential improvements to this study design include a more uniform means of administering caffeine to participants, such as
caffeine pills.
Discussion