Driskell, J. E., Copper, C., & Moran, A. (1994). Does mental practice enhance performance?. Journal of Applied Psychology, 79(4), 481.
@Article{DriskellCopperMoran2994,
author = {Driskell, J. E. and Copper, C. and Moran, A.},
title = {Does mental practice enhance performance?},
journal = {Journal of Applied Psychology},
year = {1994},
volume = {79},
number = {4},
pages = {481}
}
this article sought to integrate disparate studies and identify the conditions in which mental
practice will be most effective.
The authors begin with a definition of mental practice: “the cognitive rehearsal of a task in the
absence of overt physical movement.” Examples include a musician thinking through a difficult
passage in a piece, or an athlete visualizing the steps required to perform a task.
Previously, Feltz and Landers (1983) conducted a meta-analysis of studies investigating the
effects of mental practice on performance, but their inclusion criteria was not stringent by the
current authors’ standards. For example, Feltz and Landers (1983) included studies that used
composite treatments of mental and physical practice, and also included “mental preparation” as
a form of mental practice. “Mental preparation” includes all sorts of “psyching-up” strategies
that may moderate levels of emotional arousal- an example of which would be the repetition of
the self-efficacy statement “I can do it”. It is difficult to draw conclusions about the efficacy of
mental practice from Feltz and Landers’s (1983) meta-analysis because of this less stringent
inclusion criterion.
Conversely, this meta-analysis by Driskell, Copper, and Moran (1994) is restricted to studies that
compare the effect of mental practice (as defined above) to a no mental practice condition. In the
event that included studies also reported an effect size for a physical practice-only condition,
these data were aggregated to evaluate the efficacy of mental practice compared to physical
practice.
In addition to investigating the overall effects of mental practice, the authors were interested in
identifying the conditions in which mental practice would be most effective. Five moderators
were included in this analysis: type of task (whether tasks are more cognitive or physical in
nature), retention interval (the time between the last mental practice period and performance),
experience level (are subjects novices or experienced), duration of practice, and type of control
(no-contact wait-listed control group vs. an equivalent control group).
The “type of task” moderator was rated by two independent judges according to 6 qualities of the
task. Three qualities were related to the physical demands of the task: muscular strength,
endurance, and coordination. Three qualities were related to the cognitive demands of the task:
perceptual input (which describes skills requiring participants to search for and acquire
information, observe, read, monitor, scan, identify, and locate), mental operations (which
describes skills requiring participants to compare and contrast information, organize, analyze,
categorize, generate hypotheses, and apply principles), and output and response (which describes
skills requiring participants to make decisions, solve problems, make judgments, and evaluate).
Tasks were then sorted according to the judges’ ratings of the degree to which the task was
cognitive or physical in nature.
Overall effects:
The combined effect size of mental practice across 62 hypothesis tests was small to
moderate (r = .255, d = .527, p < .001) and significant. NFail-Safe (p = .05) = 4,129, which
means that it would take 4,129 studies with null results to render the overall effect size of
mental practice non-significant.
The combined effect size of physical practice across 39 hypothesis tests was moderate to
strong in magnitude (r = .364, d = .782, p < .001) and significant.
The focused comparison of the difference between the overall magnitude of the effect for
mental practice and the magnitude of effect for physical practice was significant (z =
3.946, p < .001), indicating that the overall effects of mental practice and physical
practice differ.
Type of task:
Mental practice was effective for both cognitive and physical tasks, but was increasingly
effective the more the task was cognitive in nature.
For cognitive tasks, the effect of mental practice was moderated primarily by the tasks’
dependence on mental operations, followed by output and response characteristics, and
then perceptual input activities. All of these moderators moderated the efficacy of mental
practice in a positive direction, but to varying degrees.
Qualities of the physical task moderated the efficacy of mental practice: more strength-
based tasks attenuated the effect of mental practice, as did coordination-based tasks albeit
to a lesser degree. The degree of endurance required by the physical task had no relation
to the effect of mental practice.
Retention interval:
Mental practice had the greatest effect on performance when performance was tested
immediately after the mental practice period. After 2 weeks, the effect of mental practice
has been reduced by approximately half its initial value. At 21 days, the effect size of
mental practice was less than .1.
Experience level:
Initially, it appeared that the effects of mental practice were equivalent for novices and
experts. However, closer examination of the data suggests that this result is qualified by
task type. For novices, mental practice had a significantly greater effect on tasks that
were primarily cognitive in nature as opposed to physical in nature. For experienced
participants, however, there was no significant difference in the effect of mental practice
on tasks that were primarily cognitive or physical in nature.
Duration:
There was a significant negative relation between the duration of mental practice and the
magnitude of the effect. In other words, the longer someone mentally practices, the less
beneficial it becomes. The mean effect size for mental practice can be achieved with an
approximate mental practice length of 20.8 minutes.
Concluding thoughts:
“Mental practice offers the opportunity to rehearse behaviors and to code behaviors into easily
remembered words and images to aid recall. Mental practice does not offer direct knowledge of
results or visual and tactile feedback.” Thus, one potential reason why the effect of mental
practice on performance is less than the effect of physical practice on performance is because of
the lack of immediate feedback provided by mental practice.
Summary author's notes: