According to some researchers, most of the results so far indicate that
cognitive function is not affected significantly by short-term fasting (Green
et al., 1995, p. 246). However, this conclusion seems premature due to the
relative lack of research on cognitive functions such as concentration and
perseverance. To date, no study has tested perseverance, despite its
importance in cognitive functioning. In fact, perseverance may be a better
indicator than achievement tests in assessing growth in learning and
thinking abilities, as perseverance helps in solving complex problems
(Costa, 1984). Another study also recognized that perseverance, better
learning techniques, and effort are cognitions worth studying (D’Agostino,
1996). Testing as many aspects of cognition as possible is key because the
nature of the task is important when interpreting the link between food
deprivation and cognitive performance (Smith & Kendrick, 1992).
guide readers through the researchers’
The researchers explain how
their study will add to
past research on the topic.
support their decision to
focus on concentration
Running on Empty 5
Therefore, the current study helps us understand how short-term food
deprivation affects concentration on and perseverance with a difficult task.
Specifically, participants deprived of food for 24 hours were expected to
perform worse on a concentration test and a perseverance task than those
deprived for 12 hours, who in turn were predicted to perform worse than
those who were not deprived of food.
Participants included 51 undergraduate-student volunteers (32
females, 19 males), some of whom received a small amount of extra credit
in a college course. The mean college grade point average (GPA) was 3.19.
Potential participants were excluded if they were dieting, menstruating,
or taking special medication. Those who were struggling with or had
struggled with an eating disorder were excluded, as were potential
participants addicted to nicotine or caffeine.
Concentration speed and accuracy were measured using an online
numbers-matching test (www.psychtests.com/tests/iq/concentration.html)
that consisted of 26 lines of 25 numbers each. In 6 minutes, participants
were required to find pairs of numbers in each line that added up to 10.
Scores were calculated as the percentage of correctly identified pairs out of
a possible 120. Perseverance was measured with a puzzle that contained
five octagons—each of which included a stencil of a specific object (such
as an animal or a flower). The octagons were to be placed on top of
each other in a specific way to make the silhouette of a rabbit. However,
three of the shapes were slightly altered so that the task was impossible.
Perseverance scores were calculated as the number of minutes that a
participant spent on the puzzle task before giving up.
At an initial meeting, participants gave informed consent. Each
consent form contained an assigned identification number and requested
the participant’s GPA. Students were then informed that they would be
notified by e-mail and telephone about their assignment to one of the
The researchers state their