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ORIGINAL RESEARCH
Creativity in Narcolepsy Type 1: The Role of
Dissociated REM Sleep Manifestations
This article was published in the following Dove Press journal:
Nature and Science of Sleep
Anita D’Anselmo
1,2
Sergio Agnoli
2,3
Marco Filardi
1
Fabio Pizza
1,4
Serena Mastria
2,3
Giovanni Emanuele
Corazza
2,3,5
Giuseppe Plazzi
4,6
1
Department of Biomedical and
Neuromotor Sciences (DIBINEM),
University of Bologna, Bologna, Italy;
2
Marconi Institute for Creativity (MIC),
Bologna, Italy;
3
Department of Electrical,
Electronic, and Information Engineering
“Guglielmo Marconi”, University of
Bologna, Bologna, Italy;
4
IRCCS Istituto
delle Scienze Neurologiche di Bologna,
Bologna, Italy;
5
Université de Paris and
Univ Gustave Eiffel, LaPEA, Paris, France;
6
Department of Biomedical, Metabolic
and Neural Sciences, University of
Modena and Reggio Emilia, Modena, Italy
Purpose: A higher creative potential has been reported in narcoleptic patients and linked to
lucid dreaming. The aim of the present study was to explore the role of narcolepsy symptoms
(presence and severity) in predicting creativity.
Patients and Methods: Sixty-six consecutive type 1 narcolepsy patients (mean age 38.62
± 17.05, 31 females) took part in this study. Creative achievement in different life domains
and creative beliefs were assessed by a self-reported questionnaire and a scale measuring the
creative self, respectively; creative performance was measured through a divergent thinking
test (generation of alternative original solutions to an open problem).
Results: We found a key effect of hypnagogic hallucinations in modulating creative
behaviour. We therefore tested at rst whether hypnagogic hallucinations could interact
with specic mental states associated with creativity and in particular mind wandering,
a factor associated with both creative performance and achievement. Secondly, we veried
if hypnagogic hallucinations could inuence the denition of creative identity in type 1
narcolepsy patients, which in turn could predict their creative achievement and creative
performance. Results showed that spontaneous mind wandering inuenced creative achieve-
ment through a moderation effect of sleep paralysis and hypnagogic hallucinations.
Moreover, sleep paralysis and hypnagogic hallucinations indirectly inuenced, through
creative identity, both creative achievement and performance (uency score).
Conclusion: Our results highlight the role of hypnagogic hallucinations in triggering the
process of mind wandering which leads to greater creative success. In addition, this symptom
affects creative identity in narcolepsy, leading in turn to higher creative success and creative
potential of narcoleptic patients.
Keywords: narcolepsy type 1, creativity, hypnagogic hallucinations, daydreaming, mind
wandering
Introduction
“I did not sleep but wandered
in that limbo where objects change shape, the mysterious
tracts that separate waking from sleep”
Gustavo Adolfo Bécquer
1
Narcolepsy type 1 (NT1) is a chronic neurological disorder characterised by
excessive daytime sleepiness (EDS), with rapid access into REM sleep at sleep
onset. Naps can occur several times during the day and are frequently characterized
by dreaming with recall of the dream content.
2–4
NT1 patients also experience
Correspondence: Giuseppe Plazzi
IRCCS Istituto delle Scienze
Neurologiche di Bologna, Via Altura N°3,
Bologna 40139, Italy
Tel +39 051 4966929
Fax +39 051 4966176
Email giuseppe.plazzi@unibo.it
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http://doi.org/10.2147/NSS.S277647
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clinical phenomena related to wake/REM sleep dissocia-
tion, including cataplexy, sleep paralysis, hypnagogic/hyp-
nopompic hallucinations and REM sleep behaviour
disorder (ICSD-III).
5
Given the features of abnormal REM sleep manifestation
in narcolepsy, with privileged access to sleep and dreaming,
a recent study assessed whether lucid dreaming (the phenom-
enon of being aware of dreaming during the dream) could
inuence creative abilities.
6,7
The authors showed that nar-
colepsy patients have a higher creative potential compared to
controls, both in terms of creative prole and of creative
achievement. Moreover, narcoleptic patients showed an
overall better creative performance in an objective test that
evaluated creative abilities, in particular, they scored higher
in an integrative task (measuring ideas’ originality) and
tended to achieve better scores in a divergent task (measuring
the ability to produce multiple ideas) compared to controls.
Finally, sleep paralysis, hypnagogic/hypnopompic hallucina-
tions, REM sleep behaviour disorder and lucid dreaming
were associated with a more highly creative prole, suggest-
ing that the privileged access to REM sleep could provide
a gateway to creativity.
Anecdotally sleep-related hallucinations, eeting per-
ceptual experiences generally characterized by vivid per-
ceptions occurring at sleep/wake transitions and vice
versa, have been related to the creative process in several
cases.
8–10
The most famous is probably the story of
August Kekulè, which describes how the hypnagogic
image of a swirling snake biting its tail and this vision
allowed him to discover the structure of benzene.
11
Although it has long been debated whether sleep-related
hallucination is a phenomenon similar to REM or NREM
sleep mentation, hypnagogic phenomena are usually char-
acterized by narrative plots and bizarre elements similar to
contents of REM sleep.
9,12–14
The aim of the present study is to explore creativity
mechanisms in NT1 patients, focusing on whether symptom
presence, frequency and course inuence creative perfor-
mance and achievements. Moreover, we explored, for the
rst time in NT1 patients, mind wandering (MW) and day-
dreaming (DD), two processes that have been associated with
creativity.
15–17
MW is an uncontrolled (spontaneous) or
intentional (deliberate) attentional shift from the ongoing
task towards internal thoughts unrelated to the task (mem-
ories, prospective thoughts) while DD refers to thoughts
immersed in fantasy and mental imaginings.
18–21
The study addresses two specic research questions: i)
whether hypnagogic hallucinations can inuence creative
achievement and creative performance through the inter-
action with specic mental states associated with creativity
(and in particular MW); and ii) whether hypnagogic hal-
lucinations can inuence the denition of the personality
of these patients, investigating their creative self-beliefs,
namely the self-beliefs to solve problems requiring think-
ing and creative functioning, i.e., creative identity. Since
creative self-beliefs are one of the most important predic-
tors of creative performance and achievement, we
expected that through this inuence hypnagogic hallucina-
tions could indirectly predict creative achievement and
creative performance of these patients.
22
Method
Participants
Sixty-six NT1 patients (mean age 38.62 ± 17.05, 31
females) were consecutively recruited at the Outpatient
Clinic of the Center for Narcolepsy of the Department of
Biomedical and Neuromotor Sciences of the University of
Bologna during routine follow-up evaluations. Inclusion
criteria for NT1 patients were age ≥ 18 years and absence
of comorbid neurologic and/or psychiatric disorders. All
patients fullled the current diagnostic criteria for NT1
(International Classication of Sleep Disorders 3rd edi-
tion, ICSD-3) presenting mean sleep-onset latency ≤8
min with at least two sleep-onset REM periods
(SOREMP) on the Multiple Sleep Latency Test (MSLT),
video-documented cataplexy, and reduced/undetectable
cerebrospinal uid hypocretin-1 (CSF hcrt-1) levels.
23,24
Mean age at diagnosis was 19.46 ± 12.13 years, mean
disease duration was 18.98 ± 10.54 years, and mean duration
of education was 12.47 ± 3.41 years (range 5–18 years).
Six patients (9%) were drug naïve/drug free, while 60
patients (91%) were on pharmacological treatment at the
time of evaluation (36 (60%) patients on pharmacological
monotherapy and 24 (4%) on pharmacological polyther-
apy). The study was carried out in accordance with the
principles of the Declaration of Helsinki and approved by
the local ethics committee (Comitato Etico Indipendente di
Area Vasta Emilia Centro - CE-AVEC - Prot. N.66930).
All participants provided written informed consent.
Materials and Procedure
Questionnaire
All participants lled in questionnaires on sleepiness, NT1
symptoms’ presence and severity, creative achievement,
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creative identity, MW and DD (Italian versions of all
questionnaires have been used).
The Epworth Sleepiness Scale (ESS) was used to
assess “trait” sleepiness and the Karolinska Sleepiness
Scales (KSS) was used to assess momentary “state”
sleepiness.
25–27
NT1 symptoms’ presence and severity
were assessed with the Narcolepsy Severity Scale (NSS),
which provides three separate symptom scores: i) sleep
paralysis and hypnagogic hallucinations (SP-H), ii) exces-
sive daytime sleepiness and night-time sleep (EDS-NS)
and iii) cataplexy (CATA).
28
Creative achievement has been evaluated with the crea-
tive activity and accomplishment checklist (CAAC).
29–31
The CAAC version used in this study consists of 40 items
that cover activities in three domains: artistic, technologi-
cal, and everyday.
32
Participants had to checkmark two
responses that best described the frequency with which
they performed the activity within their working environ-
ment and outside of it, respectively.
The Short Scale of the Creative Self (SSCS) has been
used to obtain information on creative self-efcacy (CSE)
and creative personal identity (CPI).
33
Deliberate and spontaneous mind wandering (MW–D
and MW-S, respectively) were assessed with self-report
scales in which higher scores indicate a greater tendency
to engage in MW.
34,35
Finally, daydreaming was assessed
with the Daydreaming Frequency Scale (DDFS).
18,36,37
Creative Performance
Creative performance has been assessed with the
Alternative Uses Task (AUT).
38
The AUT is a measure
of divergent thinking ability, which has been shown to be
a reliable indicator of creative potential.
39
During the task,
participants are requested to generate as many uncommon/
original uses as they can for six common objects (e.g.,
a book, a chair) randomly presented. Each picture is dis-
played for three minutes, during which the participant can
type responses.
Patients’ responses were evaluated for originality by
two independent raters blind to the participants’ status
and study aims. Each response received a score rating
from 1 (not at all original) to 5 (highly original) (for
a detailed description of the task we refer the reader to
the paper by Agnoli et al).
40
The average originality
score and the uency score (number of responses pro-
duced) were considered as an indicator of creative abil-
ity or potential.
39,41
Procedure
All participants completed a computerized version of the
AUT. The task was run on a computer with a 15.4-inch
monitor using E-Prime software (Psychology Software
Tools Inc., Pittsburgh, PA, United States). At the begin-
ning and at the end of the experimental session partici-
pants lled in an electronic version of the KSS; upon
completing the AUT participants lled in the question-
naires (ESS, CAAC, SSCS, MW–D and MW–S, DDFS
and the NSS). Questionnaires’ order of presentation was
randomised to counterbalance order effects. See
Supplementary methods for a detailed description of
Materials and Procedure.
Statistical Analysis
Paired sample t-test was used to compare differences
between KSS score before and after the AUT in order to
account for a possible effect of sleepiness on test outcome.
Questionnaires’ internal consistency was calculated by
Cronbach’s α coefcient for NSS, CAAC, SSCS, MW–D,
MW–S and DDFS.
Interrater reliability for originality in the AUT was
calculated and in case of marked discrepancies in ratings
(if the score between the two raters differed by 3 or more
points on the scale used from 1 to 5), raters reviewed and
assigned scores by consensus.
Pearson correlations were used to assess the
relationship between indexes of creativity (creative
achievement, AUT uency and AUT originality), ques-
tionnaires’ score (SSCS, MW–D and MW–S and DDFS)
and clinical data (NSS, ESS, disease duration and age at
onset).
To assess whether NT1 symptoms interact with mind
wandering (MW) in the prediction of creative achievement
and creative performance, we conducted three hierarchical
multiple regression analyses including four blocks of vari-
ables (Table 1). Variables scores were centred using the
sample mean prior to be entered into the regression ana-
lysis. In the rst step, SP-H was entered; in the second
step, MW-S and MW-D were entered; in the third step, the
interaction between MW-S and SP-H was entered; in the
fourth step, we included the interaction between MW-S
and SP-H. In the three hierarchical multiple regression
analyses, the criterion variables were, respectively: crea-
tive achievement, AUT uency, and AUT originality.
Because the predictors showed important intercorrelations,
we controlled for multicollinearity.
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To test whether the SP-H symptom could indirectly
inuence creative achievement and creative performance
through its inuence on the denition of the creative self
we tested an indirect effect model (PROCESS macro for
SPSS) on the three indexes of creativity (creative achieve-
ment, AUT uency, and AUT originality);
42,43
a Bootstrap
with 5.000 samples was used to derive condence interval
for indirect effects. All indirect effect analyses included
SP-H and DD as predictor variables and creative personal
identity as mediator variable in the relationship between
SP-H and the creativity index (creative achievement, u-
ency, or originality). Because of the possible overlap
between the SP-H symptom and the process of daydream-
ing we controlled for the effect of this latter variable in the
analyses.
Data are available from the corresponding author upon
reasonable request.
Results
State sleepiness, as measured by the KSS, did not change
during the AUT task (KSS pre = 3.27 ± 1.81, post = 3.44
± 1.89; p = 0.08). The internal consistency of scales
ranged between 0.73 (acceptable) and 0.94 (excellent);
the interrater reliability calculated for the AUT task was
good (Cohen’s κ = 0.66). Demographic, clinical, neuro-
physiological data and questionnaires scores are reported
in Tables 2 and 3.
Correlations Analysis
Results of correlation analyses are reported in Table 4.
Creative achievement was positively correlated to uency
and originality. Moreover, creative success and uency in
AUT were positively correlated with both indicators of
creative identity, CSE and CPI. Originality in AUT was
Table 1 Hierarchical Multiple Regression on Creative Achievement and Creative Performance (Fluency and Originality scores)
Cr. Achievement Fluency Originality
Step 1 Step 2 Step 3 Step 4 Step 1 Step 2 Step 3 Step 4 Step 1 Step 2 Step 3 Step 4
SP-H 0.19 0.18 0.25 0.24 0.24 0.23 0.26 0.27 0.17 0.12 0.17 0.16
MW-S −0.02 0.05 0.05 −0.10 −0.08 −0.10 −0.05 −0.02 −0.02
MW-D 0.08 0.07 0.07 0.16 0.15 0.18 0.24 0.23 0.23
MW-S × SP-H −0.38** −0.36 −0.14 −0.34 −0.24 −0.21
MW-D × SP-H −0.03 0.24 −0.04
R
2
0.02 −0.01 0.12 0.10 0.04 0.02 0.02 0.02 0.01 0.02 0.06 0.04
Δ R
2
0.04 0.00 0.13 0.00 0.06 0.01 0.02 0.02 0.03 0.04 0.06 0.00
F2.43 0.87 3.12* 2.46* 3.23 1.30 1.24 1.12 1.64 1.33 1.83 1.44
ΔF2.43 0.12 9.53* 0.02 3.23 0.38 1.06 1.03 1.64 1.18 3.16 0.03
df 63 61 60 59 53 51 50 49 53 51 50 49
Notes: Step 1: SP-H; Step 2: MW-S and MW-D; Step 3: MW-S × SP-H; Step 4: MW-S × SP-H. Numbers in the rst four rows represent standardized regression coefcients;
*p<0.05, ** p < 0.01
Abbreviations: SP-H, sleep paralysis and hypnagogic hallucinations; MW-S, mind wandering spontaneous; MW-D, mind wandering deliberate.
Table 2 Demographic, Clinical and Neurophysiological
Characteristics of Patients
Mean ± SD Range
Demographic data N=66
Male/female 31/35
Age, y 38.62±17.05 18–76
Education, y 12.47±3.41 5–18
Clinical characteristics
Age at onset, y 19.46±12.13 –
Disease duration, y 18.98±10.54 –
BMI 29.95±5.12 –
BMI category
(underweight\normal\overweight\obese)
4\18\24\20
Neurophysiological data
MSLT_sl, min 4.71±3.35 –
SOREMPs, n
o
. 3.61±1.35
Biochemical data
CSFHcrt-1, pg/mL (n = 66) 56.15±1 -
HLA DQB1*0602 positivity 66
Medication used
Stimulants 13
Sodium oxybate 23
Antidepressant 13
Stimulants plus sodium oxybate 11
No medication 6
Note: HLA DQB1*0602 = positivity for human leukocyte antigen.
Abbreviations: BMI, body mass index; MSLT-sl, mean sleep latency at MSLT;
SOREMPs, sleep-onset REM periods at MSLT; CSFHcrt-1, cerebrospinal uid hypo-
cretin-1.
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positively correlated with CPI and with factor EDS-NS of
the NSS. The two indicators of creative personal identity
were correlated positively with the total NSS score and
with factor SP-H. CSE correlated positively also with
factor CATA of the NSS and CPI correlated positively
with the duration of the disease. The mental processes of
MW-S and MW-D were both correlated positively with the
process of DD and they were both correlated with the total
score of the NSS and with factor SP-H and EDS-NS of
this scale. Finally, MW-D and DD were both negatively
correlated to the age of onset of the disease: more in detail,
a lower age of onset of the disorder correlated with
a higher level of MW-D and DD.
Hierarchical Multiple Regressions
Variance ination factors showed that the three models
were exempt from multicollinearity (variance ination
factors < 10).
In the rst hierarchical multiple regression analysis
(on creative achievement), neither the introduction of
SP-H (step 1) nor the introduction of MW-S and MW-
D (step 2) produced signicant changes in the regression
model. The introduction of the interaction between MW-
S and SP-H in step 3 produced instead a signicant
change in the model. Finally, step 4, introducing the
interactions between MW-D and SP-H, did not show
any signicant increase of the explained variance in
the model.
To explain the interaction between MW-S and SP-H
observed in the regression model a simple slopes analysis
was performed aimed at exploring a possible moderation
of SP-H on the relationship between MW-S and creative
achievement. This analysis showed that the positive link
between MW-S and creative achievement was signicant
only for low levels of SP-H (ß=0.09, SE=0.04, p=0.02),
but not for medium (ß=0.02, SE=0.03, p=0.42) or high
levels (ß=−.05, SE=0.03, p=0.13) of this moderator (see
Figure 1).
Thus, the link between MW-S and creative achieve-
ment was moderated by SP-H, revealing that in NT1
patients the association between mind wandering and crea-
tive achievement is related to specic levels of this symp-
tom. In particular, the mental state of spontaneous mind
wandering appears to inuence creative achievement in
NT1 only if it is associated with low levels of the SP-H
symptom; on the contrary, at medium and high levels of
the symptom this association was not observed.
In the second hierarchical multiple regression analysis
(on the uency scores) the main effect of SP-H in step 1
and the main effects of MW-S and MW-D in step 2 were
not signicant in the prediction of uency score. The
introduction of the interactions between MW-S and SP-H
in step 3 and between MW-D and SP-H in step 4 showed
no signicant effect on the uency score.
In the third hierarchical multiple regression analysis
(on the originality scores), the main effect of SP-H in
step 1 and the main effects of MW-S and MW-D in step
2 were not signicant in the prediction of originality. The
introduction of the interaction between MW-S and SP-H in
step 3 and between MW-D and SP-H in step 4 showed no
signicant effect on the originality score. Results of the
hierarchical multiple regression analyses are shown in
Table 1.
Indirect Effect Analysis
In the rst indirect effect analysis creative achievement
was included as outcome variable. The model showed that
SP-H was positively associated with creative personal
identity (ß = 0.35, t = 2.28, p= 0.03), in addition creative
personal identity was also positively associated with crea-
tive achievement (ß = 0.02, t = 2.60, p= 0.02). While the
direct effect of SP-H on creative achievement was not
statistically signicant (ß = 0.01, t = 0.54, p = 0.59), the
indirect effect exerted through creative personal identity
Table 3 Questionnaires’ Scores
Mean ± SD Range α
ESS 10.69±4.65 1–24
BDI 8.55±7.90 0–33
Moderate (> 18), n (%) 5 (7.58%)
Severe (> 29), n (%) 3 (4.55%)
SP-H 3.41±3.66 0–14 0.79
EDS-NS 12.48±6.11 0–27 0.81
CATA 5.41±3.95 0–13 0.73
NSS 21.30±10.31 1–46 0.83
CAAC 1.58±0.34 1.00–2.66 0.93
Fluency 26.30±12.23 8–55
Originality 2.27±0.31 1.45–3.05
CSE 21.38±4.99 8–3 0.87
CPI 17.58±4.68 5–25 0.87
MW-S 3.14±1.66 1–7 0.90
MW-D 3.53±1.73 1–7 0.91
DDFS 15.63±11.22 0–48 0.94
Abbreviations: ESS, Epworth sleepiness scale; BDI, Beck Inventory Scale; SP-H,
sleep paralysis and hypnagogic hallucinations; EDS-NS, excessive daytime sleepiness
and nighttime sleep; CATA, cataplexy; NSS, narcolepsy severity scale total score;
CAAC, creative achievement; CSE, creative self-efcacy; CPI, creative personal
identity; MW-S, mind wandering spontaneous; MW-D, mind wandering deliberate;
DDFS, daydreaming.
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Table 4 Descriptive Statistics and Correlations Among the Study Variables
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
1 CAAC _
2. Fluency 0.439** _
3. Originality 0.387** 0.249 _
4. CSE 0.411** 0.349* 0.216 _
5. CPI 0.391** 0.459** 0.271* 0.792** _
6. MW-S 0.104 0.095 0.160 0.127 0.115 _
7. MW-D 0.111 0.158 0.244 0.180 0.184 0.689** _
8. SP-H 0.160 0.221 0.178 0.309* 0.253* 0.409** 0.278* _
9. EDS-NS 0.156 −.070 0.299* 0.112 0.132 0.329** 0.287* 0.339** _
10. CATA 0.058 0.017 −.022 0.272* 0.231 0.178 0.132 0.268* 0.355** _
11. NSS 0.172 0.040 0.232 0.280* 0.256* 0.408** 0.319** 0.658** 0.848** 0.688** _
12. DDFS 0.202 0.112 0.150 0.139 0.208 0.639** 0.576** 0.183 0.174 0.017 0.173 _
13. ESS −.087 −.031 0.119 −.068 −.059 0.145 0.059 0.100 0.516** 0.253* 0.440** −.080 _
14. Disease duration 0.201 0.139 0.178 0.253 0.334* 0.022 −.074 −.100 0.136 −.043 0.030 −.225 0.029 _
15. Age at onset −.130 −.063 0.064 −.144 −.075 −.158 −.263* 0.013 0.188 0.213 0.195 −.431** 0.207 0.082
Mean 1.58 26.30 2.27 21.38 17.58 3.14 3.53 3.41 12.48 5.41 21.30 15.63 10.69 18.98 19.46
SD 0.34 12.23 0.31 4.99 4.68 1.66 1.73 3.66 6.11 3.95 10.31 11.22 4.65 10.54 12.13
Notes: *p<0.05, **p<0.01.
Abbreviations: CAAC, creative achievement; CSE, creative self-efcacy; CPI, creative personal identity; MW-S, mind wandering spontaneous; MW-D, mind wandering deliberate; SP-H, sleep paralysis and hypnagogic hallucinations; EDS-
NS, excessive daytime sleepiness and night-time sleep; CATA, cataplexy; NSS, narcolepsy severity scale total score; DDFS, daydreaming; EES, Epworth Sleepiness Scale.
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emerged as statistically signicant (ß= 0.09, SE= 0.05,
95% CI = 0.01, 0.21). DD did not turn out to be signi-
cantly associated either with creative achievement (ß =
0.01 t = 1.13, p = 0.26) or to creative personal identity
(ß = 0.06 t = 1.28, p = 0.20). Finally, the total effect of SP-
H on creative achievement, which included the indirect
effect through creative personal identity, was not signi-
cant (ß = 0.01, t = 1.26, p= 0.21) (Figure 2). This model
revealed that a higher frequency of SP-H does not exert
a direct inuence on creative achievement, but it does
through an indirect effect via creative personal identity,
which in turn leads to higher creative achievement. DD
instead did not emerge as a signicant variable in these
relationships.
In the second indirect effect analysis uency in the
AUT task was included as outcome variable. The model
showed that SP-H was positively associated with creative
personal identity (ß = 0.38, t = 2.38, p = 0.02), in addition
creative personal identity was positively associated with
uency (ß = 1.18, t = 3.28, p = 0.00). The direct effect of
SP-H on uency was not statistically signicant (ß = 0.25,
t = 0.56, p = 0.58), while the indirect effect exerted
through creative personal identity was statistically signi-
cant (ß = 0.13, SE = 0.06, 95% CI = 0.03, 0.26). Again,
DD emerged to be not signicantly associated either with
uency (ß = −.01, t = −.11, p = 0.91) or with creative
personal identity (ß = 0.08, t = 1.53, p = 0.13). Finally, the
total effect of SP-H on uency, which included the indirect
effect through creative personal identity, was not signi-
cant (ß = 0.69, t = 1.52, p = 0.13). Again, this analysis
showed that whereas the frequency of SP-H does not
directly inuence the ability to produce many alternative
ideas (i.e., uency in the AUT), it indirectly affects this
ability via its inuence on dening creative personal iden-
tity (see Figure 3).
In the third indirect effect analysis originality in the
AUT task was included as outcome variable. The model
showed that while SP-H was positively associated with
creative personal identity (ß = 0.38, t = 2.38 p = 0.02),
creative personal identity was not associated with origin-
ality (ß = 0.02, t = 1.54, p = 0.13). The direct effect of SP-
H on originality was not statistically signicant (ß = 0.01,
t = 0.62, p = 0.54), likewise DD was not signicantly
associated either with originality (ß = 0.00, t = 0.56, p =
0.58) or with creative personal identity (ß = 0.08, t = 1.53,
p = 0.13). This analysis showed that SP-H has not effect
(either direct or indirect) on originality.
Discussion
A main nding that emerges from our study is that hypna-
gogic hallucinations play an important role in predicting
Figure 1 Moderating effect of sleep paralysis and hypnagogic hallucinations (SP-H)
on spontaneous mind wandering (MW-S) in the prediction of creative achievement
(CAAC).
Figure 2 Path diagram of the mediation model showing that SP-H was positively
associated with CPI, which was also positively associated with CAAC.
Unstandardized β regression coefcients are reported (*p < 0.05). The values
without parentheses represent the total effect, while the value inside the parenth-
eses represents the direct effect of SP-H on CAAC.
Figure 3 Path diagram of the mediation model showing that SP-H was positively
associated with CPI, which was also positively associated with AUT uency.
Unstandardized β regression coefcients are reported (*p < 0.05, **p < 0.01).
The values without parentheses represent the total effect, while the value inside
the parentheses represents the direct effect of SP-H on uency.
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NT1 patients’ creative achievement, through its interaction
with the mental state of MW.
In line with scientic literature in the eld of creativity,
our results show a relationship between creative achieve-
ment and creative performance in a divergent thinking
task.
44
Further, a relation has been found among creativity
aspects and CSE, which could be considered one of the
best predictors of creative achievement and creative
performance.
45–47
Our study showed that a relationship between narco-
leptic symptoms and creativity emerged in the domain of
self-perception of creativity. A positive association was
found indeed between creative self-efcacy and creative
personal identity and the severity of the disease (as mea-
sured by the NSS scale), in particular with SP-H factor.
A link between the course of the disease and MW-S and
MW-D is also supported by the positive correlation
between these mental states and the NSS. The correlation
is signicant especially for the factor SP-H and excessive
daytime sleepiness, suggesting that NT1 symptomatology
could stimulate the process of MW. Consistent with these
results, we also found a negative correlation between the
age of onset of the disease and the process of MW and
DD: a lower age at the onset of narcolepsy may lead to
a greater development of these mental processes.
The hierarchical multiple regression analysis revealed
that a greater level of creative success was achieved when
MW-S interacted with a low level of SP-H, whereas at
medium and high levels of this symptom, no interactive
effect emerged. According to studies showing the effect of
exposure to external stimuli in affecting the occurrence of
MW episodes, also low frequency of hypnagogic halluci-
nations could thus represent a triggering mechanism for
MW in NT1 patients.
20,48,49
The result showing that the
spontaneous form of MW interacted with hypnagogic hal-
lucinations emerges to be consistent with this explanation.
Whereas deliberate MW is a mental state deliberately
activated by a person, spontaneous MW is usually trig-
gered by external, involuntary cues. Hypnagogic halluci-
nations could therefore represent a mechanism that,
independently form the patient’s decision, can trigger, if
at low levels, the train of thoughts characterizing the mind
wandering state.
Whereas SP-H interacts with spontaneous MW tenden-
cies, in predicting creative achievement, no interactive
effect emerged in the prediction of creative performance
in terms of uency and originality in the AUT. Even if
creative achievement and creative performance are
commonly associated constructs, they capture distinct ele-
ments of the creative phenomenology. Creative achievement
refers to the creative success achieved by a person during
her/his lifetime, creative performance as measured in the
present study captures instead the divergent thinking ability
to generate a multitude of original ideas, a measure of an
individual’s creative potential. It is worth highlighting that
NT1 patients experience the phenomenon of hypnagogic
hallucinations during their life in the course of several
years, and they probably turn this symptomatology into an
advantage, which can therefore represent a favourable con-
text for achieving in different creative activities.
Furthermore, our indirect effect analysis showed that
SP-H exerted an indirect effect through the creative perso-
nal identity both on creativity achievement and on the
creative performance (in the uency index but not in
originality score in the AUT). SP-H emerged therefore to
inuence, even if indirectly, the creative behaviour
through its effect on the creative identity of the patients.
These results suggest that in narcoleptic patients there is
an association between self-perception of creativity and
hypnagogic phenomena. Intriguingly, we found that crea-
tive personal identity was positively associated with the
duration of the disease. This suggests that a longer course
of disease can affect the beliefs to be creative and conse-
quently to succeed in several creative activities.
Our results further extend the results of a recent study
showing a positive association among symptoms (sleep
paralysis, hypnagogic hallucinations, lucid dreaming and
REM sleep behaviour disorder) and a higher creative prole
evaluated in narcoleptic patients.
7
In the study of Lacaux et al
this greater creative prole highlighted in subjects with nar-
colepsy has been explained in relation to frequent lucid
dreams reported by narcoleptic patients and to their higher
ability to recall dreams content compared to controls.
6,7,50
In
the same way as lucid dreaming has a positive impact on
creativity in normal subjects, and in narcoleptic patients, our
study showed that also hypnagogic hallucinations may posi-
tively predict creativity in narcolepsy, exerting an indirect
effect through creative personal identity.
7,51
Regarding drug therapy, at the time of the test the
majority of patients (91%) were on pharmacological treat-
ment, with more than half of them being treated with
sodium oxybate. In literature, it is reported that when on
medication a reduction of dream recall frequency can
occur and that sodium oxybate may decrease sleep paraly-
sis and hypnagogic hallucinations.
50,52,53
Nevertheless, we
found similar scores in creative success and creative
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D’Anselmo et al Dovepress
performance between patients treated and untreated with
sodium oxybate, with a positive effect of this drug for
sleepiness and cataplexy but not for sleep paralysis and
hallucinations (Supplementary material, Table S1).
Some limitations should be acknowledged. First, our
study did not include a control group. However, we aimed
at addressing the mechanisms underlying creativity in NT1.
Second, our sample of patients is not homogeneous as
regards the age range and the age at onset of the disease,
a variety that however allowed the analysis of the impact of
disease duration on creativity features and mechanisms.
To sum up, our study highlights the role of hypnagogic
hallucinations in dening both creative success and crea-
tive performance of narcoleptic patients by interacting
with patients’ mental states leading to higher creativity
as well as by inuencing their creative identity. On the
one hand, this symptom could represent the mechanism
that triggers the process of mind wandering and that leads
to greater creative success. On the other hand, it can dene
patients’ creative identity, which in turn can lead to higher
creative success and creative potential.
Informing patients about these ndings could be useful in
order to increase awareness of their creative potential. In this
way, patients could learn how to manage some symptoms
and turn them into their advantage in everyday life.
Acknowledgments
We are indebted to all the patients participating in this
study, most notably the Italian Association of Narcolepsy
(AIN onlus) patients. Without their contributions, this
study would not have been possible. We also thank
Cecilia Baroncini for editing the English text.
Disclosure
Giuseppe Plazzi participated in advisory boards for and
received personal fees from UCB, Jazz pharmaceuticals,
Bioprojet and Idorsia, outside the submitted work. The
authors report no other potential conicts of interest for
this work.
References
1. Cohen JM. The Penguin Book of Spanish Verse. Ed. Cohen JM,
Penguin UK; 1988.
2. Vogel G. Studies in psychophysiology of dreams: III. The dream of
narcolepsy. Arch Gen Psychiatry. 1960;3(4):421–428. doi:10.1001/
archpsyc.1960.01710040091011
3. Guilleminault C, Fromherz S. Narcolepsy: diagnosis and management.
In: Kryger MH, Roth T, Dement WC, editors. Principles and Practice
of Sleep Medicine. 4th ed. Elsevier Saunders; 2005:780–790.
4. D’Atri A, Scarpelli S, Schiappa C, et al. Cortical activation during
sleep predicts dream experience in narcolepsy. Ann Clin Transl
Neurol. 2019;6(3):445–455. doi:10.1002/acn3.718
5. American Academy of Sleep Medicine. International Classication
of Sleep Disorders. 3rd. Darien, IL: American Academy of Sleep
Medicine; 2014:ICSD3. doi:10.1378/chest.14-0970
6. Dodet P, Chavez M, Leu-Semenescu S, Golmard JL, Arnulf I. Lucid
dreaming in narcolepsy. Sleep. 2015;38(3):487–497. doi:10.5665/
sleep.4516
7. Lacaux C, Izabelle C, Santantonio G, et al. Increased creative think-
ing in narcolepsy. Brain. 2019;142(7):1988–1999. doi:10.1093/brain/
awz137
8. Maury A. Des hallucinations hypnagogiques, ou des erreurs des sens
dans l’état intermédiaire entre la veilleet le sommeil. L. Martinet;
1848. doi: 12148/bpt6k5740964t
9. Foulkes D, Vogel G. Mental activity at sleep onset. J Abnorm
Psychol. 1965;70(4):231. doi:10.1037/h0022217
10. Mavromatis A. Ed. Hypnagogia: The Unique State of Consciousness
Between Wakefulness and Sleep. Routledge; 1987.
11. Mazzarello P. What dreams may come? Nature. 2000;408(6812):523.
doi:10.1038/35046170
12. Foulkes SPS, Symonds JD. Individual differences in mental activity
at sleep onset. J Abnorm Psychol. 1966;71(4):280. doi:10.1037/
h0023581
13. Wollman MC, Antrobus JS. Cortical arousal and mentation in sleep-
ing and waking subjects. Brain Cogn. 1987;6(3):334–346. doi:10.10
16/0278-2626(87)90130-8
14. Nielsen TA. A review of mentation in REM and NREM sleep:
“covert” REM sleep as a possible reconciliation of two opposing
models. Behav Brain Sci. 2000;23(6):851–866. doi:10.1017/S01405
25X0000399X
15. McMillan R, Kaufman SB, Singer JL. Ode to positive constructive
daydreaming. Front Psychol. 2013;4:626. doi:10.3389/fpsyg.
2013.00626
16. Agnoli S, Vannucci M, Pelagatti, Corazza GE. Exploring the Link
Between Mind Wandering, Mindfulness, and Creativity: A
Multidimensional Approach. Creat Res J. 2018;30(1):41–53.
doi:10.1080/10400419.2018.1411423
17. Zedelius CM, Schooler JW. The richness of inner experience: relating
styles of daydreaming to creative processes. Front Psychol.
2016;6:2063. doi:10.3389/fpsyg.2015.02063
18. Giambra LM. The inuence of aging on spontaneous shifts of
attention from external stimuli to the contents of consciousness.
Exp Gerontol. 1993;28(4–5):485–492. doi:10.1016/0531-5565(93)
90073-M
19. Smallwood J. Distinguishing how from why the mind wanders:
a process–occurrence framework for self-generated mental activity.
Psychol Bull. 2013;139(3):519. doi:10.1037/a0030010
20. Vannucci M, Pelagatti C, Marchetti I. Manipulating cues in mind
wandering: verbal cues affect the frequency and the temporal focus of
mind wandering. Conscious Cogn. 2017;53:61–69. doi:10.1016/j.
concog.2017.06.004
21. Seli P, Risko EF, Smilek D, Schacter DL. Mind-wandering with and
without intention. Trends Cogn Sci. 2016;20(8):605–617. doi:10.10
16/j.tics.2016.05.010
22. Beghetto RA, Kaufman JC, Baxter J. Answering the unexpected
questions: exploring the relationship between students’ creative self-
efcacy and teacher ratings of creativity. Psychol Aesthet Creat Arts.
2011;5(4):342. doi:10.1037/a0022834
23. Littner MR, Kushida C, Wise M, et al. Practice parameters for
clinical use of the multiple sleep latency test and the maintenance
of wakefulness test. Sleep. 2005;28(1):113–121. doi:10.1093/sleep/
28.1.113
24. Vandi S, Pizza F, Antelmi E, et al. A standardized test to document
cataplexy. Sleep Med. 2019;53:197–204. doi:10.1016/j.sleep.2017.
08.021
Nature and Science of Sleep 2020:12 submit your manuscript | www.dovepress.com
DovePress
1199
Dovepress D’Anselmo et al
25. Johns MW. Reliability and factor analysis of the Epworth sleepiness
scale. Sleep. 1992;15(4):376–381. doi:10.1093/sleep/15.4.376
26. Vignatelli L, Plazzi G, Barbato A, et al. Italian version of the
Epworth sleepiness scale: external validity. Neurol Sci. 2003;23
(6):295–300. doi:10.1007/s100720300004
27. Åkerstedt T, Gillberg M. Subjective and objective sleepiness in the
active individual. Int J Neurosci. 1990;52(1–2):29–37. doi:10.3109/
00207459008994241
28. Dauvilliers Y, Beziat S, Pesenti C, et al. Measurement of narcolepsy
symptoms: the narcolepsy severity scale. Neurology. 2017;88
(14):1358–1365. doi:10.1212/WNL.0000000000003787
29. Milgram RM, Hong E. Creative out-of-school activities in intellec-
tually gifted adolescents as predictors of their life accomplishment in
young adults: a longitudinal study. Creat Res J. 1999;12(2):77–87.
doi:10.1207/s15326934crj1202_1
30. Runco MA, Noble EP, Luptak Y. Agreement between mothers and
sons on ratings of creative activity. Educ Psychol Meas. 1990;50
(3):673–680. doi:10.1177/0013164490503025
31. Agnoli S, Corazza GE, Runco MA. Estimating creativity with a
multiple-measurement approach within scientic and artistic
domains. Creat Res J. 2016;28(2):171–176. doi:10.1080/104004
19.2016.1162475
32. Agnoli S, Mastria S, Kirsch C, Corazza GE. Creativity in the adver-
tisement domain: the role of experience on creative achievement.
Front Psychol. 2019;10:1899. doi:10.3389/fpsyg.2019.01899
33. Karwowski M, Lebuda I, Wiśniewska E. Measurement of creative
self-efcacy and creative role-identity. High Abil Stud. 2012;
22:291.
34. Carriere JS, Seli P, Smilek D. Wandering in both mind and body:
individual differences in mind wandering and inattention predict
dgeting. Can J Exp Psychol. 2013;67(1):19. doi:10.1037/a0031438
35. Chiorri C, Vannucci M. Replicability of the psychometric properties
of trait-levels measures of spontaneous and deliberate mind
wandering. Eur J Psychol Assess. 2019;35(4):459. doi:10.1027/
1015-5759/a000422
36. Singer JL, Antrobus JS. A factor-analytic study of daydreaming and
conceptually-related cognitive and personality variables. Percept Mot
Skills. 1963;17(1):187–209. doi:10.2466/pms.1963.17.1.187
37. Stawarczyk D, Majerus S, Van der Linden M, D’Argembeau A.
Using the daydreaming frequency scale to investigate the relation-
ships between mind-wandering, psychological well-being, and
present-moment awareness. Front Psychol. 2012;3:363. doi:10.33
89/fpsyg.2012.00363
38. Guilford JP. Creativity: yesterday, today and tomorrow. J Creat
Behav. 1967;1(1):3–14. doi:10.1002/j.2162-6057.1967.tb00002.x
39. Runco MA, Acar S. Divergent thinking as an indicator of creative
potential. Creat Res J. 2012;24(1):66–75. doi:10.1080/10400419.
2012.652929
40. Agnoli S, Franchin L, Rubaltelli E, Corazza GE. An eye-tracking
analysis of irrelevance processing as moderator of openness and
creative performance. Creat Res J. 2015;27(2):125–132. doi:10.10
80/10400419.2015.1030304
41. Runco MA. Divergent Thinking. Norwood, NJ: Ablex Publishing
Corporation; 1991.
42. Hayes AF, Matthes J. Computational procedures for probing interac-
tions in OLS and logistic regression: SPSS and SAS
implementations. Behav Res Methods. 2009;41(3):924–936. doi:10.
3758/BRM.41.3.924
43. Hayes AF. Introduction to Mediation, Moderation, and Conditional
Process Analysis: A Regression-Based Approach. Guilford publica-
tions; 2017.
44. Kim KH. Meta-analyses of the relationship of creative achievement
to both IQ and divergent thinking test scores. J Creat Behav. 2008;42
(2):106–130. doi:10.1002/j.2162-6057.2008.tb01290.x
45. Beghetto RA. Creative self-efcacy: correlates in middle and second-
ary students. Creat Res J. 2006;18(4):447–457. doi:10.1207/s1532
6934crj1804_4
46. Jaussi KS, Randel AE, Dionne SD. I am, I think I can, and I do: the
role of personal identity, self-efcacy, and cross-application of
experiences in creativity at work. Creat Res J. 2007;19(2–3):247–-
258. doi:10.1080/10400410701397339
47. Tierney P, Farmer SM. Creative self-efcacy development and crea-
tive performance over time. J Appl Psychol. 2011;96(2):277.
doi:10.1037/a0020952
48. Maillet D, Seli P, Schacter DL. Mind-wandering and task stimuli:
stimulus-dependent thoughts inuence performance on memory tasks
and are more often past-versus future-oriented. Conscious Cogn.
2017;52:55–67. doi:10.1016/j.concog.2017.04.014
49. Pelagatti C, Binda P, Vannucci M. Tracking the dynamics of mind
wandering: insights from pupillometry. J Cogn. 2018;1:1. doi:10.53
34/joc.41
50. Rak M, Beitinger P, Steiger A, Schredl M, Dresler M. Increased lucid
dreaming frequency in narcolepsy. Sleep. 2015;38(5):787–792.
doi:10.5665/sleep.4676
51. Zink N, Pietrowsky R. Relationship between lucid dreaming, crea-
tivity and dream characteristics. Int J Dream Res. 2013;6(2):98–103.
doi:10.11588/ijodr.2013.2.10640
52. US Xyrem
®
Multicenter Study Group. A randomized, double blind,
placebo-controlled multicenter trial comparing the effects of three
doses of orally administered sodium oxybate with placebo for the
treatment of narcolepsy. Sleep. 2002;25(1):42–49. doi:10.1093/sleep/
25.1.42
53. Thorpy MJ, Bogan RK. Update on the pharmacologic management of
narcolepsy: mechanisms of action and clinical implications. Sleep
Med. 2020;68:97–109. doi:10.1016/j.sleep.2019.09.001
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