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ROBERT G. MORRISON
SEAN W. MCCARTHY
JOHN M. MOLONY
The Experience of Insight Follows Incubation in
the Compound Remote Associates Task
ABSTRACT
The phenomenon of insight is frequently characterized by the experience of a sudden
and certain solution. Anecdotal accounts suggest that insight frequently occurs after the
problem solver has taken some time away from the problem (i.e., incubation). However,
the mechanism by which incubation may facilitate insight problem-solving remains
unclear. Here, we used compound remote associates problems to explore the likely mech-
anisms by which incubation may facilitate problem-solving. First, we manipulated prob-
lem fixation to explore whether forgetting can explain incubation effects. Second,
leveraging previous work linking the experience of insight to unconscious semantic inte-
gration, we asked participants to report their experience of insight after each problem
solution, including problems solved after a period of distracted incubation. We hypothe-
sized that incubation was not principally important for forgetting but rather frequently
causes a shift to a more unconscious semantic integration strategy. Consistent with this
we found that initial problem fixation did not predict the improvement in problem-solving
after incubation and that participants were more likely to report insight on problems
solved after incubation. Our findings suggest that incubation may facilitate insight
problem-solving leading to a mind-set shift to a more unconscious problem-solving
strategy involving semantic integration.
Keywords: fixation, incubation, insight, problem-solving.
People frequently describe solving problems with either an analytic, step-by-step pro-
cess (Morrison, 2014), or a comparatively unconscious process resulting in unexpected
answers (van Steenburgh, Fleck, Beeman, & Kounios, 2012). In the latter situation people
show little ability to predict their sudden insight (Metcalfe, 1986), yet have great confi-
dence in the solution that seemingly came from unconscious processing (Simonton,
2012; Smith & Ward, 2012). This experience often follows time away from the problem,
frequently referred to as incubation. However, relatively little is known about the mecha-
nisms by which incubation may facilitate insight problem-solving.
Beginning with the Gestalt psychologists, researchers attempted to create problems
where the experience of insight was more likely [e.g., Duncker and Lees (1945) Candle
Problem; Katona’s (1940) Matchstick Arithmetic Problems; Mednick’s (1962) Remote
Associates Problems]. To delineate the different ways that participants might solve these
types of problems, researchers have asked participants to monitor their problem-solving
1The Journal of Creative Behavior, Vol. 0, Iss. 0, pp. 1–10 ©2015 by the Creative Education Foundation, Inc. ÓDOI: 10.1002/jocb.96
Morrison, R.G., McCarthy, S., & Molony, J., (2015). The
experience of insight follows incubation in the compound
remote associates task. Journal of Creative Behavior. Doi:
10.1002/jocb.96
progress in situ (e.g., Metcalfe, 1986) or alternately to report whether they experienced
insight prior to problem solution (e.g., Bowden & Jung-Beeman, 2003a). This latter
approach allows researchers to better identify problems likely solved with insight and
compare them to problems solved with other problem-solving strategies. Alternatively,
some studies have examined how problem-solving context could facilitate insight solu-
tions (e.g., Baird et al., 2012; Kounios et al., 2008; Smith & Blankenship, 1991; Storm
& Angello, 2010; Storm, Angello, & Bjork, 2011; Wallas, 1926). For instance, Smith
and Blankenship (1991) argued that incubation allows problem solvers to forget (or
perhaps inhibit) mental representations causing problem fixation and thereby achieve
an insight solution. In this study, we bring together these approaches to investigate
possible mechanisms for how a period of distracted incubation may facilitate insight
problem-solving.
INCUBATION DURING INSIGHT PROBLEM-SOLVING
Building on an earlier study by Smith and Blankenship (1991), Kohn and Smith
(2009) asked participants to solve remote associates problems in which participants
must discover a single word that is a remote associate of three different words. Prior
to attempting to solve each problem participants completed an initial task designed
to manipulate the level of fixation experienced while trying to solve the remote asso-
ciates problems. Participants briefly tried to solve each remote associates problem and
then were given either a second continuous solution period or a brief 30-second
incubation period during which they performed a working-memory distractor
task. Kohn and Smith found a trend toward participants showing improved perfor-
mance after incubation for problems on which they were initially more fixated. They
suggested that the period of distracted incubation might have assisted by allowing
participants to forget their initial mental representations responsible for problem
fixation.
Dijksterhuis and Meurs (2006) conducted a series of experiments looking to under-
stand the relationship between active and passive incubation with the formation of
creative ideas. They found that a period of active incubation during idea generation
tasks resulted in significantly more divergently generated words, more remotely associ-
ated (non-cued) words, and in a non-cued paradigm, more creative words suggesting
that what one does during incubation may impact the effectiveness of incubation.
Likewise, using a different type of insight problem, Baird et al. (2012) also found a
benefit of active incubation; however, the greatest benefit was found not from a diffi-
cult distractor task, but rather from a task designed to promote mind-wandering.
Furthermore, a sleep study by Cai, Mednick, Harrison, Kanady, and Mednick (2009)
demonstrated that either a period of rest or sleep improved performance on remote
associate problems that participants attempted to solve prior to incubation, but not
to new remote associates problems. In addition, REM sleep, a process frequently asso-
ciated with unconscious semantic integration, helped participants take advantage of
implicit priming of correct answers performed after an initial attempt to solve the
problems but before sleep. These results suggest that the benefit of incubation
may not be primarily to help participants forget the mental representations causing
fixation but rather to promote unconscious neurocognitive processing conducive to
insight.
2
Insight Follows Incubation
NEUROCOGNITIVE MECHANISMS OF INSIGHT
Bowden and Jung-Beeman (2003a) developed a subjective measure of insight for
use with compound remote associates problems (CRA; Bowden & Jung-Beeman,
2003b) which are more standardized variants of Mednick’s (1962) classic remote asso-
ciates task problems. Bowden and Jung-Beeman (2003a) asked participants after they
had solved a CRA problem to report via a numeric scale, how much insight they
had experienced. Jung-Beeman and colleagues (Bowden & Jung-Beeman, 2003b; Jung-
Beeman et al., 2004; Kounios et al., 2006, 2008) have used various versions of this
methodology to perform post hoc sorting of problems based on the participant’s sub-
jective experience. Using this methodology they found evidence that processing as
measured by neural correlates differed during problem-solving when people later
reported the subjective experience of insight (Jung-Beeman et al., 2004). Using scalp
electroencephalography, neurocognitive processing immediately before insight solutions,
compared to non-insight solutions, were characterized by an increase in high
frequency (gamma) event-related oscillations in neural networks in the right anterior
superior temporal gyrus. This brain area is frequently associated with semantic
integration. Importantly, they also found evidence for neural activity (i.e., occipital
alpha event-related oscillations) indicative of visual gating just prior to the right tem-
poral activity, suggesting that solving with insight might involve inhibiting the exter-
nal world in favor of interior, perhaps unconscious processing. Likewise, Kounios
et al. (2008) identified a similar neural signature before participants even saw CRA
problems they subsequently reported solving with insight (Kounios et al., 2008),
suggesting that the mind-set during insight problem-solving could affect the type of
processing during problem-solving. Thus, problems solved with insight likely result
from unconscious semantic integration. For our present study, the experience of
insight after solving a problem can be used as an index for this type of processing,
which is distinct from the type of processing that occurs when a more analytic prob-
lem-solving strategy is employed.
STUDY OBJECTIVES
In this study, we wanted to explore whether taking time away from a problem (i.e.,
incubation) may serve to change the nature of neurocognitive processing occurring dur-
ing incubation, as indexed by the experience of insight. Furthermore, we wanted to
investigate whether this change in processing was related to forgetting the mental repre-
sentations likely resulting from problem fixation before incubation.
We adapted Kohn and Smith’s (2009) paradigm for use with CRA problems (Bowden
& Jung-Beeman, 2003b) and created a two-word task for each problem to manipulate
the degree of fixation. As in Kohn and Smith, we manipulated incubation by either giv-
ing participants a second immediate opportunity to solve the problem, or instead giving
them a period of incubation where they performed a relatively easy working-memory dis-
tractor task. We then determined the type of neurocognitive processing likely occurring
during problem-solving by asking participants to report their subjective experience of
insight (Bowden & Jung-Beeman, 2003a; Jung-Beeman et al., 2004).
We hypothesized that incubation is not primarily about forgetting mental representa-
tions responsible for problem fixation and thus solution rates after incubation would not
be impacted by problem fixation prior to incubation. Secondly, we predicted that a
3
Journal of Creative Behavior
period of distracted incubation would cause a shift toward unconscious semantic integra-
tion as indexed by the subjective experience of insight on problem solution.
METHOD
PARTICIPANTS
Eighty undergraduate students (60 female) from Loyola University Chicago partici-
pated in the experiment. Participants gave informed consent to take part in the study
and received course credit to compensate them for their time. The Loyola University
Chicago Institutional Review Board approved all recruitment methods and experimental
procedures.
TASK DESCRIPTIONS
The primary task consisted of Compound Remote Associate problems (CRA; Bowden
& Jung-Beeman, 2003b). Each CRA problem consists of three relatively unrelated words
that can each be paired with a fourth target word that is a remote associate of each to
make three compound word pairs (see Figure 1 for an example problem). Problems were
selected to represent a range of difficulty as gauged from performance data in Bowden
and Jung-Beeman (2003b).
After the methods of Kohn and Smith (2009), we manipulated CRA problem fixation
through use of a preceding Two-Word Phrase Task (TWPT) problem corresponding to
each CRA problem. This task required participants to combine three presented words,
two of which were from the corresponding CRA problem, into two two-word phrases
(see Figure 1). This was intended to create a strong association for two of the CRA
words to a word that was not the correct CRA answer, and thereby induce CRA problem
fixation. We created unique stimuli for this study by finding a third word not in the
selected CRA problems that could be combined with two of the words from a given
CRA problem. We used the corresponding TWPT problem before the CRA problem in
the Blocking condition (see Figure 1b), while we used an unrelated TWPT problem
created from a different CRA problem used in the study in the Unrelated condition
(see Figure 1a).
Lastly, we used a Digit-Monitoring Task (DMT; Kohn & Smith, 2009) as the distrac-
tor task during incubation. In the DMT participants saw a series of digits from 1 to 9
presented one digit each second for 40 s. Participants were to track the total number of
times that two odd digits were presented in a row and report that at the end of the incu-
bation period.
PROCEDURE
The three tasks (TWPT, CRA, and DMT) were all implemented in e-Prime 2.0
(Schneider, Eschman, & Zuccolotto, 2002). Forty-four CRA problems were rotated
between four counterbalanced conditions (i.e., Unrelated/Direct, Unrelated/Incubate,
Blocking/Direct, Blocking/Incubate; see Figure 1 for a schematic of two of the condi-
tions). Each trial began with a TWPT problem for 20 s followed by a CRA problem. On
Direct trials if the participant did not solve the CRA problem in 20 s (Epoch 1) they
were given 10 additional seconds to solve the problem (Epoch 2). On Incubate trials if
they did not solve during Epoch 1 they performed the DMT for 40 s and then were
given an additional 10 s (Epoch 2) to solve the CRA problem. To encourage participants
4
Insight Follows Incubation
to form links between the TWPT and the CRA problems we used six additional CRA
problems in the Helping condition. In these problems the correct answer for the CRA
problem was given as the third word in the TWPT problem. CRA problems from the
Helping condition were not analyzed, but only used to increase problem fixation in the
Blocking condition.
FIGURE 1. (a) Unrelated–Direct and (b) Blocking–Incubate example trials. In Unrelated
Compound Remote Associates (CRA) trials, the preceding Two Word Phrase
Task (TWPT) problem has no words in common with the CRA problem
while in Blocking CRA trials the preceding TWPT problem contains two of
the CRA problem words which pair with a third word that is not the correct
answer for the CRA problem, thereby increasing CRA problem fixation. In
Direct CRA trials, participants have two contiguous epochs to try to solve
the CRA problem, while in Incubate CRA trials the two epochs are separated
by a 40 s incubation period in which participants perform the Digit
Monitoring Task (DMT).
5
Journal of Creative Behavior
The definition of insight given to subjects was taken from Jung-Beeman et al. (2004).
The feeling of insight was described as a sudden experience in which a fully formed
answer came to mind all at once. Upon solving a CRA, subjects were asked if they expe-
rienced insight. The subjects responded verbally with either yes or no.
RESULTS
Due to the CRAs being divided into a first 20 s epoch and a second 10 s epoch, accu-
racy was calculated using resolution rates (Kohn & Smith, 2009). For the first epoch the
resolution rate was simply equal to the proportion solved correctly. For the second epoch
we corrected for the number of problems solved in the first epoch and used the number
of problems attempted during the second epoch as the denominator in the proportion
correct calculation.
Resolution rate in the first epoch was impacted by fixation with participants solving
fewer problems when they were preceded by a blocking TWPT than an unrelated TWPT
(see Figure 2; F(1, 79) =31.18, p<.001, g
G2
=.125).
1
Next we evaluated whether per-
formance in Epoch 2 was impacted by incubation and whether this interacted with our
fixation manipulation. A two-way within subjects ANOVA yielded a main effect of incu-
bation (see Figure 2; F(1, 79) =11.5, p=.001, g
G2
=.031), but no main effect of fixa-
tion—F(1, 79) =.48, p=.5, g
G2
=.001—and no interaction—F(1, 79) =.73, p=.4,
g
G2
=.001. Following the analysis of Kohn and Smith (2009) we also performed planned
comparisons to look at the effect of incubation on Blocking and Unrelated trials inde-
pendently. As in Kohn and Smith’s study, participants showed a reliable difference in
CRA resolution rate with respect to incubation in the Blocking condition (F(1,
79) =12.0, p=.001, g
G2
=.056). However, unlike Kohn and Smith we found a trend
toward a difference for the unrelated condition as well (F(1, 79) =2.8, p=.10,
g
G2
=.015), consistent with our failure to find a reliable interaction between incubation
FIGURE 2. In Epoch 1, there was a reliable effect of blocking on CRA resolution rates
demonstrating the effectiveness of the TWPT problem fixation manipulation.
In Epoch 2, there was a reliable effect of incubation, with no interaction with
initial TWPT induced fixation. Error bars represent 1 SEM.
1
Generalized eta squared (g
G2
) was calculated according to the methods described in Bakeman (2005) and Olej-
nik and Algina (2003).
6
Insight Follows Incubation
and fixation. Thus, overall our results suggest that incubation aided in CRA problem-
solving regardless of the level of fixation as manipulated by the TWPT.
Overall, 62% of all correct answers were answered with insight and 38% were
answered without insight. In an effort to measure participant’s subjective experience of
insight within each condition, we calculated an insight score for each participant by sub-
tracting total number of correct non-insight answers from their total number of correct
insight answers and dividing by the resolution rate.
Insight score in the first epoch was impacted by fixation with participants reporting
greater insight on solution when they had less fixation as manipulated by the TWPT (see
Figure 3; F(1, 79) =6.59, p=.01, g
G2
=.022). Next, we evaluated whether the experi-
ence of insight in Epoch 2 was impacted by incubation and whether this interacted with
our fixation manipulation. A two-way within subjects ANOVA yielded a main effect of
incubation (see Figure 3; F(1, 79) =9.0, p=.004, g
G2
=.027), but no main effect of fix-
ation—F(1, 79) =2.3, p=.14, g
G2
=.005—and no interaction—F(1, 79) =.78, p=.4,
g
G2
=.002. Our results suggest that incubation increased the experience of insight, just
as it aided solution performance. Likewise, the experience of insight after incubation does
not appear to be majorly impacted by the initial degree of problem fixation.
DISCUSSION
Using a similar incubation and fixation paradigm with different remote associates
problems, Kohn and Smith (2009) reported that incubation led to higher resolution rates
when participants were subjected to a task intended to cause problem fixation. They sug-
gested that this improvement was due to distraction during incubation helping partici-
pants overcome problem fixation by forgetting wrong associations. In our study, we
found that in spite of a strong initial fixation effect, incubation helped participants solve
problems regardless of the level of fixation. In addition, participants experienced greater
FIGURE 3. In the first epoch, reports of insight were significantly higher in the
unrelated condition suggesting that overcoming fixation was not responsible
for the experience of insight. In the second epoch, reports of insight were
greater following incubation suggesting that the incubation task helped
participants to elicit a mind-set change resulting in an insight solution. Error
bars represent 1 SEM.
7
Journal of Creative Behavior
insight when they successfully solved problems after incubation regardless of fixation
compared to when they successfully solved problems in a continuous period (Direct con-
dition). Our results suggest that incubation does contribute to the experience of insight
and this likely reflects a shift toward a problem-solving strategy involving unconscious
semantic integration.
While it appears that forgetting fixation does not account for the benefit of incuba-
tion or the increased experience of insight after incubation, it is less clear how incuba-
tion facilitates problem-solving and the experience of insight. Cai et al. (2009) study
suggests that one possible mechanism may relate to unconscious processing. In their
sleep study they found that the amount of REM sleep participants experienced before
attempting Remote Associates Task problems related to effectiveness of an implicit
semantic clue prior to sleep. Thus, REM sleep may facilitate integration of semantic
information, a hypothesis consistent with Jung-Beeman and colleague’s (Bowden &
Jung-Beeman, 2003a) identification of increased gamma activity in right superior tempo-
ral cortex prior to problems successfully solved with the experience of insight. Likewise,
alpha bursts are also commonly observed during REM sleep and also prior to remote
associate solutions where participants report insight. However, to promote this type of
processing in awake problem solvers it may be necessary to distract them from the pri-
mary problem and their current problem-solving strategy. Sio and Ormerod’s (2009)
recent meta-analysis of incubation in problem-solving suggested that mildly distracting
tasks, rather than just time away from the problem optimized the effects of incubation.
However, not all distractor tasks are equally effective in promoting insight. Baird et al.
(2012) found that a more demanding task resulted in less improvement than a less
demanding task that encouraged mind wandering. Thus, it is possible that the working
memory distractor task we used during incubation in our study helped to stop analytic
processing and allowed for the type of unconscious semantic integration that facilitates
insight solutions.
Another role for incubation may be to shift the mood of the participant. In our study
when participants solved CRA problems during the first epoch prior to incubation they
reported less insight when they had previously solved a TWPT problem intended to
create CRA problem fixation than when they solved an unrelated TWPT problem (see
Figure 3 Epoch 1). It is possible that the frustration resulting from fixation may encour-
age a negative mood. Several previous studies have suggested that participants are more
likely to solve insight problems when they are in a positive mood (e.g., Isen, Daubman,
& Nowicki, 1987; Subramaniam, Kounios, Parrish, & Jung-Beeman, 2009). Subramaniam
and colleagues showed that when people were high in self-reported positive affect prior
to testing they were more likely to solve CRA problems and report insight. van Steen-
burgh et al. (2012) have speculated that this effect of positive affect may be due to the
ability of positive affect to encourage a broadening of attention (see also Rowe, Hirsch,
& Anderson, 2007). A broad attentional focus has long been known to be associated with
creative behavior (e.g., Ansburg & Hill, 2003; Mendelsohn & Griswold, 1966). While it
seems unlikely that performing the DMT incubation task in the present study would
likely elicit a positive mood it is possible that the distraction from being stuck on a
problem may result in some release from a negative mood perhaps resulting in a broader
attentional mindset. Further study is needed to determine if the initial emotional state of
a problem solver could be mitigated through tasks designed to change mind-set in spe-
8
Insight Follows Incubation
cific ways. By manipulating emotions and mind-set, it may be possible to identify
multiple cognitive conditions that lead to the subjective experience of insight in problem
solvers.
While our findings do support the idea that incubation can contribute to a change in
mindset that aids in solving problems with insight, much remains to elucidate the precise
nature of the neurocognitive changes that occurs during incubation.
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Robert G. Morrison, Sean W. McCarthy, John M. Molony, Loyola University Chicago
Correspondence concerning this article should be addressed to Robert G. Morrison, Department of Psychology,
Loyola University Chicago, 1032 W Sheridan Road, Chicago, IL 60660. E-mail: rmorrison@luc.edu
AUTHOR NOTE
The authors wish to thank Kelly Brandstadt, Stephanie Hare, and Leonidas Skiadoupolis for assistance in collecting
data and Krishna Bharani for technical support. We also thank Mark Beeman and Marcia Grabowecky for helpful
discussions and two anonymous reviewers for excellent suggestions on an earlier version of the manuscript. The
work described in this paper was presented at the International Conference on Thinking, London, England, and at
the 35th Annual Conference of the Cognitive Science Society held in Berlin, Germany.
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Insight Follows Incubation
