Sleep and creativity: a literature review.

Abstract

Sleep and creativity have been widely studied in the field of psychology, being essential to understand human behavior. However, the relationship between these variables has not been examined through a systematic literature review. The aim of this study was to realize a review of the studies that related sleep and creativity. Thus, we performed a survey of the studies conducted between 1990 and 2014, which were published in journals indexed in the major electronic databases, in particular EBSCO and Web of Science (WoS). We analyzed 1258 papers that respected the search criteria and were selected by combining the keywords " sleep " and " creativity ". Of these, 94 articles met the criteria concerning the relationship between sleep aspects and types of creativity or creative thinking. From the abovementioned articles, we picked 11 studies respecting the inclusion criteria. The obtained results indicate a positive relationship between sleep and creativity, nevertheless it was observed a significant variability in terms of sleep constructs and creativity dimensions. Although we can affirm that there is a positive relationship between these constructs, we must recognize the limits of this statement.

Full text

Advanced Research in Health, Education and Social Sciences: Towards a better practice
131
Chapter XIII
SLEEP AND CREATIVITY: A LITERATURE REVIEW
RUI MARGUILHO1, SAUL NEVES DE JESUS2, JOÃO VISEU3, RITA B.
DOMINGUES4, NATHÁLIA BRANDOLIM BECKER5, RAFAELA DIAS
MATAVELLI6, RAUL QUEVEDO7, GUALBERTO BUELA-CASAL8
1 University of Algarve, Portugal, rui.marguilho@gmail.com
2 University of Algarve, Portugal, snjesus@ualg.pt
3 University of Algarve, Portugal, joaonrviseu@gmail.com
4 University of Algarve, Portugal, rbdomingues@ualg.pt
5 University of Algarve, Portugal, nathalia_brandolim@msn.com
6 University of Algarve, Portugal, rdmpsiche@hotmail.com
7 University of Granada, Spain, rquevedo@ugr.es
8 University of Granada, Spain, gbuela@ugr.es
Note: This paper is supported by FCT (CIEO – Research Centre for Spatial and Organizational Dynamics,
University of Algarve, Portugal)
Abstract: Sleep and creativity have been widely studied in the field of psychology, being
essential to understand human behavior. However, the relationship between these variables has
not been examined through a systematic literature review. The aim of this study was to realize a
review of the studies that related sleep and creativity. Thus, we performed a survey of the
studies conducted between 1990 and 2014, which were published in journals indexed in the
major electronic databases, in particular EBSCO and Web of Science (WoS). We analyzed 1258
papers that respected the search criteria and were selected by combining the keywords “sleep”
and “creativity”. Of these, 94 articles met the criteria concerning the relationship between
sleep aspects and types of creativity or creative thinking. From the abovementioned articles, we
picked 11 studies respecting the inclusion criteria. The obtained results indicate a positive
relationship between sleep and creativity, nevertheless it was observed a significant variability
in terms of sleep constructs and creativity dimensions. Although we can affirm that there is a
positive relationship between these constructs, we must recognize the limits of this statement.
Key-words: creativity, sleep, systematic literature review.
INTRODUCTION
Sleep is a complex behavioral state and one
of the greatest mysteries of modern
neuroscience (Rechtschaffen & Bergmann,
2002). Yet, the latest approaches and
techniques are already able to describe and
interpret many of its’ biological mechanisms
(Carter et al., 2012), providing not only a
description of the sleeping conditions, but
also of the processes that lead to a good
quality of sleep (Miró, Cano-Lozano, &
Buela-Casal, 2005). During sleep, the brain
does not process the information received by
the sense organs, however it is an active
brain state (Pace-Schott & Hobson, 2002).
One of the most important contributions of
sleep is the development of new synapses
and memory consolidation (Ashworth, Hill,
Karmiloff-Smith, & Dimitriou, 2014).
Indeed, sleep consolidates recent memories
and, at the same time, allows implicit
information processing by changing its’
representational structure (Diekelmann &
Born, 2010).
Consolidation theory suggests that, through
sleep, both learning and memory processing

Sibiu, Romania, June 2015
132
benefit creativity, and new memories are
favored by memory representations
reactivated, becoming stronger, more robust,
and preserved in a long period of time
(Marrone, Schaner, McNaughton, Worley, &
Barnes, 2008; Oudiette et al., 2011). Rapid
eye movement (REM) sleep, in particular,
increases the creative process more than any
other sleep phase, helping the formation of
new associative networks in the brain and
useful connections between ideas, working
as an enabler for creativity (Cai, Mednick,
Harrison, Kanady, & Mednick, 2009). Both
scientists and artists have suggested that
sleep facilitates creativity (Ritter, Strick, Bos,
Van Baaren, & Dijksterhuis, 2012).
The direct relationships between sleep and
creativity have rarely been addressed, but
studies relating sleep to cognitive skills, such
as memory and motivation, suggested that
sleep may directly influence learning and the
formation of new concepts, ideas, or
solutions, in other words it leads to the
development of creativity (Marguilho, Jesus,
Viseu, Rus, & Brandolim, 2014).
An individual can state that he is in the
presence of creativity when something new
is produced, whether it is a product, a
decision, a process, or an insight. Wagner,
Gais, Haider, Verleger, and Born (2004)
reinforced this idea. They affirmed that sleep
consolidates recent memories and, in
consequence, develops a new insight over a
problem, allowing a change in the structural
representation of the subject. For instance,
Healey and Runco (2006) observed that
children were able to learn a new task and
improve their performance after a sleep
period. This learning process also involves
other aspects, such as motivation and certain
aspects of personality (Jesus, Rus, Lens, &
Imaginário, 2013).
Nowadays, creativity is recognized as an
urgent transdisciplinar and transcultural
requirement (Kaufman & Sternberg, 2006).
A growing research interest in creativity has
been observed in recent years, most likely
because this concept is the most effective
and natural answer to the world’s increasing
complexity (Runco, 2004). Innovation, new
solutions and decisions, better education, and
high competitive work environments have
turned creativity into a valuable asset and
research theme, despite its’ complex nature
(Starko, 2010).
The main goal of this study was to provide a
literature summary regarding the relationship
between sleep and creativity. To our
knowledge, this is the first literature review
relating these constructs. We also aimed to
suggest paths for future research on sleep
and creativity.
METHOD
Data Sources
The selection of studies was conducted in
January 2015 focused on the papers
published between 1990 and 2014, using the
electronic databases Web of Science (WoS)
and EBSCO. The inclusion criteria defined
were: (a) English, French, Spanish, and
Portuguese as publication languages; (b)
studies published in peer-reviewed scientific
journals; and (c) presence of the necessary
data to analyze what has been studied and
how it was studied. The keywords used to
conduct the search were: (a) “sleep” and
“creativity”; (b) “sleep” and “creative”; and
(c) “sleep intervention” and “creativity”. The
studies included in the literature review and
cited in the present manuscript are identified
with an asterisk (*) in the references section.
Procedure
Search results were coded to facilitate
comparisons using the following criteria: (a)
author; (b) year; (c) sample size; (d) sample
type (i.e., children, adolescents, adults, and
the elderly); (e) type of creativity (i.e.,
product, process, person, and situation); (f)
type of sleep (i.e., quality, insomnia, REM
sleep, and dreams); and (g) type of study.
The taxonomy of Montero and León (2007)
was applied for the studies’ classification. In
the first stage, 1258 articles were selected.
After reading the abstracts, only studies
containing empirical data on the relationship
between sleep and creativity were
considered. Afterwards, a full reading of the
documents allowed choosing those that
contained relevant statistical information. In

Advanced Research in Health, Education and Social Sciences: Towards a better practice
133
Initial sample:
1258 studies
94 studies
13 studies
Final sample:
11 studies
Abstract selection (n = 1164)
Application of the inclusion criteria: (a) type of study; (b) type of
sample; (c) variable of sleep and instrument; (d) variable of
creativity and instrument; and (e) internal consistency analysis and
statistical indicator (n = 81)
Assessment of repeated samples (n = 2)
a third step, we assessed the occurrence of
repeated studies.
RESULTS
Theoretically, we confirmed that the selected
studies were based on identical assumptions.
The characterization of sleep had the same
approach, although there were differences in
relation to: (a) sleep stage analyzed; (b) sleep
quantity/quality; and (c)
morningness/eveningness factors. Also, in
creativity, we found differences in the
studied aspects, some studies focused on the
(a) creative process; (b) creative personality;
and (c) product creation. The selection
criterion was to not discriminate between
these factors, since they all addressed
different perspectives of creativity. The
methodological approach was the same in all
studies. They presented empirical
characteristics and correlation values that
could be subject to objective analysis and
comparison. After the first selection, we
identified 1258 articles. The selection of
abstracts reduced our sample to 94 studies,
which were read taking into consideration
the criteria: (a) type of study; (b) type of
sample; (c) variable of sleep and instrument;
(d) variable of creativity and instrument; and
(e) internal consistency analysis and
statistical indicator. This analysis retrieved
13 articles, of these, 2 were rejected because
they referred to the same sample. A total of
11 articles, identified by an asterisk in the
references section, were the basis for the
present literature review (Figure 1).
Figure 1. Flow of studies in each phase of the systematic literature review. On the left are the studies that
remained after each phase. On the right are the removed studies in each evaluation step
With regard to the studies’ participants, we
registered a total of 6629 participants. Of
those, 2174 were males and 4376 were
females (Table 1). The percentage of males
(32.80%) is lower relatively to the
percentage of females (67.20%). The highest
sample was found in one article (Brand et
al., 2011), which represented 84% of the
total of participants. The age of the
participants varied between 20 and 30 years
old (young-adults), in turn only 9% of the
sample included children and elderly.
Table 1. Characteristics of the Participants Included in the Literature Review (N = 6629)

Sibiu, Romania, June 2015
134
I
D Authors Type of sample
(Age/Status) N
Total M/F
1 Wimmer et al. (1992) All ages/General population 12 12/0
2
Schredl (1995)
Young/Students and
working population
94
62/32
3
Randazzo et al. (1998)
Young/Students and
working population
16
7/9
4
Schredl (2004)
Young/Students and
working population
444
68/376
5 Healey and Runco (2006) Children/Students 60 27/33
6 Giesbrecht and Merckelbach (2006) Young/Students 205 65/140
7
Giampetro and Cavallera (2007)
Young, adult, and
elderly/Students and
working population
120
52/68
8 Cai et al. (2009) Young/Working population 77 a
9 Brand et al. (2011) Young and adults/Students 5580 1869/3711
1
0 Drago et al. (2011) Adults/Working population 8 4/4
1
1 Vartanian et al. (2014) Adults/Working population 13 10/3
Total 6629 2176/4376
Note. M = Male; F = Female; a This study did not discriminate the participants by gender.
Several instruments were used to assess
sleep and creativity, according to the purpose
of each author and taking into account that
both constructs include several factors that
can be analyzed. At an earlier stage of this
review, the instruments most commonly
used to measure creativity and sleep were,
respectively, the Torrance Test of Creative
Thinking and the Pittsburg Quality Sleep
Test. In the final phase of the review,
regarding the sleep variable, the most used
instruments were the Dreamuse
questionnaire and polysomnography (Table
2).
The main conclusions regarding the
relationship between sleep and creativity are
presented in Table 4.
Table 2. Characteristics of the Instruments Used in Studies Included in the Systematic Review
ID Sleep variable Creativity variable
Type Instrument Type Instrument
1 Dream Dreamuse questionnaire Person Self-defined
2 Dream Dream Recall Frequency Person The verbal creativity test of Schoppe (1975)
3 Sleep quality Multiple sleep latency test Person Attitude Towards Creativity
4 Sleep quality SF-B Sleep Questionnaire Person Attitude Towards Creativity
5 Sleep quality Child Depression Process Torrance Test of Creative Thinking

Advanced Research in Health, Education and Social Sciences: Towards a better practice
135
Note. “Type” refers to the type of sleep or creativity considered by each study.
Overall, studies showed a moderate and
statistically significant (p < .05) correlation
between sleep and creativity, with an
arithmetic mean of .27 and weighted average
of .34 (Table 3). Below, we can observe the
correlation results between the variables of
sleep and creativity. Study 11 (Vartanian et
al., 2014) does not possess a correlation
value, but we kept it due to the clear
presentation of its results.
Table 3. Correlation Scores in the Analyzed Studies
ID Authors r
1 Schredl (2004) .19
2 Schredl (1995) .27
3 Randazzo et al. (1998) .33
4 Wimmer et al. (1992) .26
5 Healey and Runco (2006) .31
6 Giesbrecht and Merckelbach (2006) .38
7 Brand et al. (2011) .35
8 Cai et al. (2009) .26
9 Giampetro and Cavallera (2007) .18
10 Drago et al. (2011) .13
11 Vartanian et al. (2014) -
Mean .27
Note. r = correlation coefficient value; All r values were statistically significant (p < .05).
Table 4. Main Results of Each of the Analyzed Studies
ID Results
1
This study suggested that sleep plays a functional role in the discovery of new reasoning
processes to solve problems raised in the previous day. However, the type of sleep that enabled
this process was not analyzed.
2
The sleep variable in this study was the dream recall frequency. The authors concluded that
people with greater creativity have greater recall of their dreams.
3
This study compared the performance, in a cognitive test, of 16 subjects after periods of REM and
NREM (non-rapid eye movement) sleep, and wakefulness. The tests applied after REM sleep
were associated with better results in 32% of cases. The results suggested that REM sleep
facilitates new ways to solve problems, better than NREM sleep and wakefulness.
6 Dissociative
experiences
Dissociative Experiences Scale Person
Creative Experiences Questionnaire
7 Morningness /
eveningness
Reduced Morningness – Eveningness
Questionnaire
Process
Torrance Test of Creative Thinking
8 REM sleep Polysomnography
Process
RAT - Related Association Test
9 Sleep
quality/quantity
Pittsburgh Sleep Quality Index Person NEO-PI-R, German version
10 Sleep patterns
(REM/NREM)
Polysomnography
Process
Torrance Test of Creative Thinking
11 Sleep quantity Stanford Sleepiness Scale Person Big Five Inventory (BFI)/MRI

Sibiu, Romania, June 2015
136
4
The findings of this research showed a positive relationship between the memory of dreams and
creativity and openness to new experiences.
5
There was a significant difference between the sleeping patterns of children who had higher
results in creativity tests comparatively to those that had lower scores on the same creativity tests.
6
Dissociation and fantasy proneness were related to some types of sleep experiences, such as
narcolepsy or vivid dreams.
7
Data showed that eveningness was correlated with the ability to apply divergent thinking
strategies to visual content. The subjects prone to the night dimension (i.e., sleep pattern in which
the subject has a sleep routine during the morning and wakefulness during the late night) had
higher results in the components of creative thinking, fluidity, flexibility, and originality. We can
assume that the evening type individuals tend to possess more ideas, hypotheses, and memories,
allowing them to easily change their conceptual strategy.
8
REM sleep facilitated the formation of new combinations between ideas and the integration of
new ideas. The study also indicated that sleep develops creative solutions, facilitating the
connection between the information available in the brain through cholinergic and noradrenergic
neuromodulation during REM sleep.
9
This study had the largest sample, therefore the most representative. The results indicated a
significant and positive correlation (r = .21, p = .01) between sleep quality and creativity, and a
moderate and significant correlation (r = .35, p = .01) between the amount of sleep and creativity.
The authors stated that sleep enhanced creative problem solving for items that were primed before
sleep, but this was only true for naps that included REM sleep.
10
NREM sleep is associated with low levels of cortical arousal, which can increase the ability to
access remote associations that are critical for creative innovations. Furthermore, the A1 cycle
(NREM sleep cycles, A1-A4) reflects the frontal lobe activity. The frontal lobes are important for
divergent thinking, a critical aspect of creativity.
11
The results of this study revealed, with high consistency, that openness to experience is related to
working memory processes, decision making, persistence, and concentration occurring in the pre-
frontal cortex.
SLEEP
Studies 9 (Brand et al., 2011), 5 (Healey &
Runco, 2006), 4 (Schredl, 2004), 3
(Randazzo et al., 1998), and 11 (Vartanian et
al., 2014) analyzed the quantity and quality
of sleep. These variables are usually
employed in exploratory studies, given that
the instruments use participants’ responses
and no experimental observation is required.
Studies 8 (Cai et al., 2009) and 10 (Drago et
al., 2011) assessed sleep cycles (i.e., REM
and NREM) which are important factors in
sleep analysis and allowed the understanding
of their relationship with creativity. Studies 2
(Schredl, 1995) and 4 (Schredl, 2004)
evaluated the dream as part of sleep. Study 6
(Giesbrecht & Merckelbach, 2006) measured
dissociative experiences during sleep. Lastly,
study 11 (Vartanian et al., 2014) analyzed
the amount of sleep using subjects that slept
for 8 hours and sleep-deprived subjects after
one night.
Regarding the instruments, the authors used
different options, but we emphasize the
difference between self-response instruments
and the ones’ employed in clinical studies
(polysomnography). This method (i.e.,
polysomnography) is used in medicine and
measures different aspects of sleep and
variables such as electroencephalography
(EEG), eye movement, musculoskeletal
activity, or electrocardiogram (ECG). Within
our selection, the variables analyzed were
REM and NREM sleep.
CREATIVITY
Meusburger, Funke, and Wunder (2009)
found more than 100 definitions in the
literature about this concept. Similarly,
Hilário et al. (2010) identified 239
instruments to assess creativity. So, for this
review, we have not defined any parameters
regarding which instrument was used by the
authors.
The selected researches indicate that studies
5 (Healy & Runco, 2006), 8 (Cai et al.,
2009), 9 (Giampetro & Cavallera, 2007), and
10 (Vartanian et al., 2014) used the

Advanced Research in Health, Education and Social Sciences: Towards a better practice
137
dimension process to assess creativity and
the other studies employed the dimension
person. This option is understandable, given
that the assessment of the dimensions
product or situation would require an
experimental approach, where the subject
would have to create a product or interact in
a situation.
Concerning the measures applied, we
highlight the use of the Torrance Test of
Creative Thinking. This instrument, which
measures creativity as a process, was created
by Torrance, Torrance, Williams, and Horng
(1978) based on the work of Guilford in the
1950’s and originally involved verbal and
non-verbal tasks that assess factors such as
flexibility, fluency, originality, and
elaboration.
NEO-PI-R (German version: Ostendorf &
Angleitner, 1994) was one of the other
instruments used. It measures, essentially,
the person dimension of creativity and is
based on the analysis of five major
personality traits (i.e., neuroticism,
extraversion, openness to experience,
agreeableness, and conscientiousness).
DISCUSSION
Our study showed that sleep has a positive
influence on creativity, confirming the
hypothesis that these two constructs are
related. However, the analysis also showed
the existence of different factors in sleep
processes which should be thoroughly
analyzed, particularly their relationships with
creativity and its’ different dimensions.
Positive relationships between creativity and
dreams have been observed by several
authors (e.g., Brand et al., 2011; Schredl,
1995, 2004). These relationships were
confirmed by the test of creative
performance after periods of REM sleep,
demonstrating that this type of sleep
promoted the formation of associated
memories and integration of non-associated
information (Cai et al., 2009). NREM sleep
may also be important for creativity, given
that this sleep stage is associated with low
levels of cortical arousal, which can increase
the ability to access remote associations that
are critical for creative innovations (Drago et
al., 2011). Likewise, NREM sleep reflects
frontal lobe activity which is important for
divergent thinking, a vital aspect of
creativity (Drago et al., 2011).
Morningness and eveningness are also
important aspects for creativity. Giampetro
and Cavallera (2007) showed that
eveningness was correlated with the ability
to apply different thinking strategies to
visual content. Subjects with an eveningness
sleep pattern were more open to new
experiences and presented greater divergent
thinking. The subjects with a morningness
pattern had higher results in creative
thinking, as fluidity, flexibility, and
originality, while the evening type tended to
create more ideas, hypotheses, and
memories, allowing them to easily change
their conceptual strategy. The question of
sleep schedules may be an important factor
in creativity, in many cases working at night
might have a significant impact on cognitive
and professional performance.
Regarding sleep quality, Healy and Runco
(2006) observed a significant difference, in
sleep quality, between children with
different creativity levels. Indeed, sleep
deprived children had worse results in
creativity tests in relation to well-slept
children (Randazzo et al., 1998).
In the case of creativity, there are also
different perspectives in the published
studies. Only two dimensions of creativity
were studied, person and process. Creativity
associated with personality (i.e., creative
person) refers to an individual characteristic
and process (i.e., creative process) is the
bridge between the person and the product.
Three of the four studies that examined the
process dimension used the Torrance Test of
Creative Thinking. This instrument is a self-
report questionnaire that has been adapted
and perfected over the years, and is widely
used and accepted for creativity assessment.
Findings of the studies which evaluated the
process dimension of creativity (studies 5, 7,
8, and 10) showed a direct relationship
between sleep and forms of creative
thinking, whether verbally, visually, or
verbal fluency. With regard to the person
dimension, it was also observed, in the

Sibiu, Romania, June 2015
138
remaining studies, a positive relationship
with sleep. Subjects submitted to creativity
tests revealed to be more open to new
experiences, have the ability to use divergent
thinking, and motivation for new tasks.
Cai et al. (2009) registered that sleep
enhanced creative problem solving for items
that were primed before sleep, but only for
naps that included REM sleep. Contrasting
with these results, Drago et al. (2011)
observed that subjects with NREM sleep
time produced more remote associations and
divergent thinking, increasing creativity.
Moreover, Wimmer et al. (1992) and
Randazzo et al. (1998) found differences in
creative abilities in sleep restricted
individuals. These individuals had worse
performance in creativity measures. These
conclusions are shared by Vartanian et al.
(2014) which adds a more complete analysis
in aspects such as working memory,
concentration, and resilience through
magnetic resonance imaging (MRI) and by
biologically locating these processes.
According to this author, sleep loss has a
negative influence on pre-frontal cortex,
impairing functions like fluency and
divergent thinking.
Few attributes of human performance have
so much impact on our lives as creativity,
which can be improved through training
(Scott et al., 2004). Although there are ways
to facilitate and develop creativity,
unconscious processes have been seldom
addressed and introduced in various contexts
(Ritter & Dijksterhuis, 2014). The benefits
of an incubation period (i.e., performing less
demanding tasks for shorter interleaved
periods) are clear for the development of
creativity (Sio & Ormerod, 2009), and
include, for instance, the improvement of the
verbal component of this concept (Davies,
Gilhooly, Gilhooly, Harries, & Cairns,
2013).
Considering sleep as a multifaceted
phenomenon, we can conclude that there is a
positive relationship between the different
sleep structures and the various dimensions
of creativity. However, research on the
relationships between sleep and creativity is
scarce and these results indicate that sleep
should be considered as a major issue with
regard to creativity and innovation. A good
sleep routine can indeed increase levels of
innovation, creative solutions, and
development of new strategies in education,
management, marketing, research, and other
creative areas.
Nevertheless this relationship is not
straightforward. Future research should
consider possible moderators and mediators,
by evaluating, for instance, the combination
of conscious and unconscious processes, or
verify how practical knowledge, amount of
time, and investment in a task can change
sleep influence on decision making and
creative production. Another critical aspect
in sleep and creativity research is to
understand if individuals with previous
knowledge on a subject exhibit the same
creativity level after sleep than individuals
without any prior knowledge, but benefiting
from sleep. Also, other studies should
deepen some critical issues such as sleep
patterns and cycles, and quality and quantity
of sleep. There are also gaps in studies
dealing with the different dimensions of
creativity, which could open new
perspectives for further research.
Understanding and training creativity and
creative thinking plays an important role in
many different areas, such as education,
management, research, and arts. Therefore, a
continued investment in creativity research is
essential for human and economic
development. We believe that intervention
programs on creativity must take in
consideration different conditions, such as
level of knowledge in the area in question,
motivation, and other cognitive issues (e.g.,
stress, anxiety, resilience, and fluency).
Research in this area must take these factors
into account as mediators in the relation
between sleep and creativity. Despite the
influence of other variables, we may state
that, in general, sleep has a positive
influence on creativity and that this
relationship should be examined in future
studies.

Advanced Research in Health, Education and Social Sciences: Towards a better practice
139
REFERENCES
Ashworth, A., Hill, C. M., Karmiloff-Smith,
A., & Dimitriou, D. (2014). Sleep enhances
memory consolidation in children. Journal
of Sleep Research, 23(3), 302-308. doi:
10.1111/jsr.12119
*Brand, S., Beck., J., Kalak, N., Gerber,
Kirov, V., Puhse, U.,… Holsboer-Trachsler,
E. (2011). Dream recall and its relationship
to sleep, perceived stress, and creativity
among adolescents. Journal of Adolescent
Health, 49(5), 525–531. doi:
10.1016/j.jadohealth.2011.04.004
*Cai, D. J., Mednick, S. A., Harrison, E. M.,
Kanady, J. C., & Mednick, S. C. (2009).
REM, not incubation, improves creativity by
priming associative networks. Proceedings
of the National Academy of Sciences of the
United States of America, 106(25), 10130–
10134. doi: 10.1073/pnas.0900271106
Carter, M., Brill, J., Bonnavion, P.,
Huguenard, J., Huerta, R., & Lecea, L.
(2012). Mechanism for hypocretin-mediated
sleep-to-wake transitions. Proceedings of the
National Academy of Sciences of the United
States of America, 109(39), 2635-2644. doi:
10.1073/pnas.1202526109
*Drago, V., Foster, P., Heilman, K., Aricò,
D., Williamson, J., Montagna, P., & Ferri, R.
(2011). Cyclic alternating pattern in sleep
and its relationship to creativity. Sleep
Medicine, 12(4), 361–366. doi:
10.1016/j.sleep.2010.11.009
Diekelmann, S., & Born, J. (2010). The
memory function of sleep. Nature Reviews
Neuroscience, 11, 114-126. doi:
10.1038/nrn2762
Davies, M., Gilhooly, M., Gilhooly K.,
Harries P., & Cairns D. (2013). Factors
influencing decision-making by social care
and health sector professionals in cases of
elder financial abuse. European Journal of
Ageing, 10(4), 313-323. doi:
10.1007/s10433-013-0279-3
*Giampietro, M., & Cavallera, M. (2007).
Morning and evening types and creative
thinking. Personality and Individual
Differences, 42, 453–463. doi:
10.1016/j.paid.2006.06.027
*Giesbrecht, T., & Merckelbach, H. (2006).
Dreaming to reduce fantasy? Fantasy
proneness, dissociation, and subjective sleep
experiences. Personality and Individual
Differences, 41(4), 697-706. doi:
10.1016/j.paid.2006.02.015
Guilford, J. P. (1950). Creativity. American
Psychologist, 5, 444–454. doi:
10.1037/h0063487
Hilário, J., Martinho, J., Godinho, P.,
Martins, A., Pacheco, A., Mendonça, S., &
Jesus, S. N. (2010). Instrumentos de
avaliação da criatividade: Revisão da
literatura. VII Simpósio Nacional de
Investigação em Psicologia. Braga:
Universidade do Minho.
*Healey, D., & Runco, M. A. (2006). Could
creativity be associated with insomnia?.
Creativity Research Journal, 18(1) 39-43.
doi: 10.1207/s15326934crj801_5
Jesus, S. N., Rus, C., Lens, W., &
Imaginário, S. (2013). Creativity and
intrinsic motivation: A meta-analysis of the
studies between 1990-2010. Creativity
Research Journal, 25(1), 80-84. doi:
10.1080/10400419.2013.752235
Kaufman, J. C., & Sternberg, R. J. (2006).
The international handbook of creativity.
Cambridge: Cambridge University Press.
Marguilho, R., Jesus, S. N., Viseu, J., Rus,
C., & Brandolim, N. (2014). Sleep and
creativity: A quantitative review. In M.
Milcu, H. Krall, & P. Dan (Eds.),
Prospecting interdisciplinarity in health,
education and social sciences (pp. 117-126).
Bucharest: Editura Universitara.
Marrone. D., Schaner J., McNaughton B.,
Worley P., & Barnes C. (2008). Immediate-
early gene expression at rest recapitulates
recent experience. The Journal of
Neuroscience, 28(5), 1030 –1033. doi:
10.1523/JNEUROSCI.4235-07.2008
Meusburger, P., Funke, J., & Wunder, E.
(2009). Introduction: The spatiality of
creativity. In P. Meusburger, J. Funke, & E.
Wunder (Eds.), Knowledge and Space (vol.
2, pp. 97-153). New York: Springer.
Miró, E., Cano-Lozano, M., & Buela-Casal,
G. (2005). Sueño y calidad de vida. Revista
Colombiana de Psicología, 14, 11-27.

Sibiu, Romania, June 2015
140
Montero, I., & Léon, O. (2007). A guide for
naming research studies in psychology.
International Journal of Clinical and Health
Psychology, 7(3), 847-862.
Ostendorf, F., & Angleitner, A. (1994). A
comparison of different instruments
proposed to measure the Big Five. European
Review of Applied Psychology, 44, 45-53.
Oudiette, D., Constantinescu, I., Leclair-
Visonneau, L., Vidailhet, M., Schwartz, S.,
& Arnulf, I. (2011). Evidence for the re-
enactment of a recently learned behavior
during sleepwalking. PLoS ONE, 6(3),
18056. doi: 10.1371/journal.pone.0018056
Pace-Schott, E. F., & Hobson, J. A. (2002).
The neurobiology of sleep: Genetics, cellular
physiology and subcortical networks. Nature
Reviews Neuroscience, 3, 591-605. doi:
10.1038/nrn895
*Randazzo, A., Muehlbach, M., Schweitzer,
P., & Walsh, J. (1998). Cognitive function
following acute sleep restriction in children
ages 10-14. Journal of Sleep Research,
21(8), 861-868.
Rechtschaffen, A., & Bergmann, B. M.
(2002). Sleep deprivation in the rat: An
update of the 1989 paper. Sleep, 25(1), 18-
24.
Ritter, M., & Dijksterhuis, A. (2014).
Creativity: The unconscious foundations of
the incubation period. Frontiers in Human
Neuroscience, 8, 215. doi:
10.3389/fnhum.2014.00215
Ritter, S., Strick, M., Bos, M., Van Baaren,
R., & Dijksterhuis, A. (2012). Good morning
creativity: Task reactivation during sleep
enhances beneficial effect of sleep on
creative performance. Journal of Sleep
Research, 21(6), 643-647. doi:
10.1111/j.1365-2869.2012.01006.x
Runco, A. (2004). Creativity. Annual
Review of Psychology, 55, 657-687. doi:
10.1146/annurev.psych.55.090902.141502
Scott G., Leritz L. E., & Mumford M. D.
(2004). The effectiveness of creativity
training: A quantitative review. Creativity
Research Journal, 16, 361–388. doi:
10.1080/10400410409534549
Schredl, M. (1995). Creativity and dream
recall. Journal of Creative Behavior, 29(1),
16-24. doi: 10.1002/j.2162-
6057.1995.tb01420.x
*Schredl, M. (2004). Dream report length
and dream recall frequency: Are they
affected by the same factors?. Advances in
Psychology Research, 28, 15-25. doi:
10.2190/IC.28.4.e
Sio, U., & Ormerod, T. (2009). Does
incubation enhance problem solving? A
meta-analytic review. Psychological Bulletin,
135(1), 94-120. doi: 10.1037/a0014212
Starko, A. J. (2010). Creativity in the
classroom: Schools of curious delight. New
York: Routledge.
Torrance, E. P., Torrance, L. P., Williams, S.
J., & Horng, R. Y. (1978). Handbook for
training future problem solving. Athens, GA:
University of Georgia.
*Vartanian, O., Bouak, F., Caldwell, J. L.,
Cheung, B., Cupchik, G., Jobidon, M.,…
Smith, I. (2014). The effects of a single night
of sleep deprivation on fluency and
prefrontal cortex function during divergent
thinking. Frontiers in Human Neuroscience,
8, 214. doi: 10.3389/fnhum.2014.00214
Wagner, U., Gais, S., Haider, H., Verleeger,
R., & Born, J. (2004). Sleep inspires insight.
Nature, 22(427), 352-355. doi:
10.1038/nature02223
Wimmer, F., Hoffman, F., Bonato, A., &
Moffitt, R. (1992). The effects of sleep
deprivation on divergent thinking and
attention processes. Journal of Sleep
Research, 1(4), 223-230. doi:
10.1111/j.1365.2869.1992.tb00043.x