Cognitive flexibility, stress in problem solving and
When encountering a stressor, individuals endeavor to solve
the problem, or avoid the stressor, or deal with it by using a va-
riety of coping methods.1 One of these coping mechanisms is
cognitive flexibility which is defined as the capacity to shift at-
tention from one aspect of an object to another.2 It is similar to
what Nideffer3 mentioned three of the subscales relate to an ef-
fective attentional style): broad external attentional focus (BET),
broad internal attentional focus (BIT) and narrow attentional
focus (NAR) and the other three subscales refer to ineffective
attentional styles (Table 1): overloaded external focus (OET),
Print ISSN 1738-3684 / On-line ISSN 1976-3026
Copyright © 2011 Korean Neuropsychiatric Association 221
overloaded internal focus (OIT) and reduced attentional fo-
Various research studies have looked at the association be-
tween stress and anxiety and the use of learned cognitive flexi-
bility as a coping technique.4-7 Several studies suggest a relation-
ship between stressors associated with a physical response and
in the modulation of cognitive flexibility.4,7 Hillier et al.7 sug-
gested that stressors would negatively impact performance on
more complex tasks and therefore require the use of cognitive
flexibility. Moreover, coping flexibility corresponding to a stress-
ful situation has been known to be related to adaptive coping
outcomes, such as psychological and physical wellbeing, so-
cial adaptation, and reduced stress.6 Based on evidence that the
noradrenergic system increases cognitive flexibility, Beversdorf
et al.5 suggested that cognitive flexibility in problem solving
would be associated with low anxiety.
Cognitive flexibility in athletes
In sports which need coordination of several performances
simultaneously, fast and effective attentional selection and quick
extraction of task-relevant information from complex and dy-
namic sources is needed.8 As well, the ability to efficiently al-
Performance Enhancement with Low Stress and
Anxiety Modulated by Cognitive Flexibility
Doug Hyun Han1 , Hyung Woo Park1, Baik Seok Kee1, Churl Na1, Do-Hyun E. Na2 and Leonard Zaichkowsky3
1Department of Psychiatry, Chung Ang University Medical School, Seoul, Korea
2Department of Sports Marketing, DanKook University, Seoul, Korea
3Education, Graduate Medical Science & Psychiatry, Boston University, Boston, MA
ObjectiveaaThe purpose of this study was to compare cognitive flexibility abilities, stress, and anxiety between starters and non-starter
MethodsaaA total of 30 male professional-soccer and 40 professional-baseball athletes were recruited. Wisconsin Card Sorting Test (WCST)
and Trail Making Test A & B (TMT A & B) were administered to assess cognitive flexibility during competition. The Korean version of the
STAI form Y (STAI-KY) and Visual analogue scale for anxiety and stress were used to assess the anxiety and stress.
ResultsaaThe starter group had better cognitive function (fewer perseverative errors and rapid TMTB times) (Z=3.32, p<0.01; Z=2.20,
p=0.03, respectively) and lower stress and anxiety (F=4.34, p=0.01; F=6.61, p<0.01, respectively) during competition than the non-start-
ConclusionaaThe better cognitive performances were negatively correlated with stress and anxiety. Current results suggested that cog-
nitive flexibility would enhance human performance by modulation of the anxiety and stress during competition.
Psychiatry Investig 2011;8:221-226
Key Wordsaa Cognitive flexibility, Stress, Anxiety, Starter professional athletes.
Received: November 17, 2010 Revised: February 10, 2011
Accepted: March 14, 2011 Available online: July 11, 2011
Correspondence: Doug Hyun Han, MD, PhD
Department of Psychiatry, Chung Ang University Hospital, 120 Heukseong-ro,
Dongjack-gu, Seoul 156-775, Korea
Tel: +82-2-6299-3132, Fax: +82-2-6298-1508, E-mail: email@example.com
cc This is an Open Access article distributed under the terms of the Creative Commons
Attribution Non-Commercial License (http://creativecommons.org/licenses/by-
nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduc-
tion in any medium, provided the original work is properly cited.
222 Psychiatry Investig 2011;8:221-226
Performance and Cognitive Flexibility
locate attention is an important factor for success in athletes.8
Casteillo and Umilta9 suggested that repetitive practice of the
sport enabled athletes to allocate attention more quickly to the
appropriate targets. Also, skilled athletes who adapted to rap-
id changes in visual information could allocate their atten-
tion more effectively than less skilled athletes.10 They were able
to use visual scanning techniques as well as speed and anticipa-
tion to make changes in their performance.11
Assessing cognitive flexibility with Wisconsin Card
Sorting Test (WCST) and Trail Making Test (TMT)
The Wisconsin Card Sorting Test (WCST) has been used to
assess cognitive flexibility.2,12,13 Patients with prefrontal cortex
(PFC) damage showed performance deficit on the WCST and
other rule-switching tasks.14 The item most closely associated
with cognitive flexibility in the WCST is called “perseverative”
errors. Perseverative errors are those in which subjects do not
follow the feedback “correct” and “wrong”, but continue the pre-
viously correct rule.13
The Trail Making Test (TMT) is one of the commonly used
tests for assessment of attention shifting because of its high sen-
sitivity to the presence of cognitive impairment in minor stress
and trauma.15 Motor speed and agility have been found to make
a strong contribution to success on TMT.16 Actually, Ruther-
ford et al.17 estimated athlete executive function and attention
using WCST and Trail Making Test A/B in soccer athletes. Pine-
da and Merchan18 also reported that WCST and TMT A/B were
useful methods to assess executive function which had multi-
ple dimensions and different cognitive operations for antici-
pation, goal selection, organization, planning, monitoring,
shifting, controlling time, and speed, and using environmen-
We think that starter/non-starter athletes can be good sub-
jects who represent high and low performance. Based on the
previous studies and theory, we hypothesized that starters who
have good performance skills would have better cognitive flexi-
bility than non starters. Particularly, starters would use the tech-
nique of cognitive flexibility to lower the stress and anxiety lev-
els throughout competition, compared to non starters.
A total of 30 male professional-soccer athletes and 40 profes-
sional-baseball athletes were recruited. The professional-soccer
and baseball athletes were all candidates in the major soccer
league and major baseball league in Korea. Athletes who had a
history of head injury were excluded from the study. But, we did
not consider cumulative subconcussive head trauma by soccer
athletes’ heading play. Among the participants, the starters were
Table 1. Demographic characteristics (mean±SD)
*statistically significant. Sports: duration of athlete experience, WCST_C and PE: the number of achieved categories and perseverative errors
of Wisconsin Card Sorting Test, TMTA/B_SEC & error: time and number of errors Trail Making Test A and B
DH Han et al.
24 athletes, and the non starters were 46 athletes (Table 1). Be-
tween those two groups, there was no difference in age, educa-
tion and sports careers (Table 1).
The soccer team consisted of 36 athletes, 3 coaches and 1
manager. The final ranking of Korean soccer league 2005 was
7th out of 14 teams. The baseball team consisted of 68 athletes,
12 coaches and 2 managers. The final ranking of the Korean
baseball league 2005 was 6th out of 8 teams. Over a 10 year peri-
od, the soccer team had a history of being a semifinal winner
and the baseball team had a history of being champions, four
times. All participants were volunteers. Similar to Enns and Ri-
chards’10 method, the athletes were ranked into starter and
non starter categories. The rankings were done by the manager
and two coaches (offense and defense in soccer; hitting and
fielding in baseball). These rankings included such things as
dedication to training and playing ability level. When dealing
with professional athletes this may be the difference between
starters and non starters. This ranking was used to divide the
athletes into two groups; 24 starters (11 soccer and 13 baseball
athletes) and 46 non starters (19 soccer and 27 baseball). There
were 10 field players and 1 goal keep in 11 soccer starters and
there were 8 field players, 4 pitchers (starter, set up, long relief,
and closer) and 1 designated hitter in 13 starter baseball start-
ers. Although the manager and coaches arrived at their rank-
ings by consensus, the experimenter and athletes remained
blind to the rankings until testing was completed.
Before the start of their respective seasons, the WCST was ad-
ministered to assess cognitive flexibility. Additionally the Ko-
rean version of the STAI form Y (STAI-KY) was used to assess
state and trait anxiety in both soccer and baseball athletes. Im-
mediately before, during and after a game, visual analogue scales
for stress and anxiety were completed by both soccer and base-
The TMTA was administered after the first half of the game
and the TMTB for soccer athletes was administered at the end
of the game in the locker room. For baseball athletes, TMTA
after the 5th inning of the game and TMTB after the 9th inning of
the game were administered in the dugout.
Tests and scales for cognitive flexibility, stress, and
The STAI-KY was used to measure state and trait anxiety lev-
els.19 In this scale, 40 questions measured two factors; state anxi-
ety and trait anxiety. The reliability coefficient (Cronbach’s Alpha),
referring to the Korean adult normative sample, is 0.91 for state
and 0.82 for trait.20
Stress and anxiety were estimated with seven point visual an-
alogue scales for stress and anxiety which were similar to To-
WCST standard 64-item version was used (CNT40Ⓡ, Max-
medica Inc.`). The WCST consists of cards containing colored
shapes according to one of three possible rules (color, shape, and
number). If the chosen sorting rule was correct, subjects re-
ceived the feedback “correct” for a placed card. After a certain
number of correct trials, the sorting rule abruptly changes with-
out notice. Thus, subjects are provided with the feedback in-
formation “wrong” and are required to change their response be-
havior for the next trial by choosing a relevant sorting criteria
or rule, respectively. After a particular number of consecutive
successful sorts, the sorting principle changes and the partici-
pant must adjust accordingly. Scores are recorded along several
dimensions, with the number of categories achieved (WCST
C) and the number of perseverative errors (WCST PE) commit-
ted the most commonly measured category.22 The test and re-
test reliability of WCST C and PE in Korean adults were 0.584
and 0.453, respectively (p<0.05).23
TMT A & B consists of 25 numbers in the first trial (part A),
and 13 numbers and 12 letters in the second trial (part B). The
subjects draw lines on a page connecting 25 numbers consec-
utively as quickly as possible in part A. In Part B, the subjects must
draw lines alternating between numbers and letters in consec-
utive order.24 Time and number of errors were scored. The test
and re-test reliability of TMT A & B reported in Korean adults
were 0.62 and 0.53 (p< 0.05).25
Statistical analysis was performed using parametric, inde-
pendent t-tests and non-parametric, Mann-Whitney U test to
compare the mean difference of the number of achieved cate-
gories and perseverative errors in WCST and TMT-A/B be-
tween starters and non starters. The changes of stress and anxi-
ety during the game (start, middle, and end of game) between
two groups were compared using a repeated measure ANOVA.
The correlation between cognitive flexibility, stress and anxiety
checked with WCST, TMT-A/B, and the visual analogue scale
for stress and anxiety in starter and non starter groups were test-
ed using Spearman correlation. All statistical analyses were per-
formed using Statistica (Statistica version 6.0, Stat Soft).
There was no significant differences in the age, education,
athlete experience, and marital status between starters and non
starters (Z=1.54, p=0.12; Z=0.61, p=0.54; Z=1.70, p=0.09; χ2=
0.24, p=0.89, respectively). Starters (37.0±6.4) showed lower
state anxiety than non starters (43.0±8.5). There was no dif-
ference in trait anxiety between the two groups (Table 1).
224 Psychiatry Investig 2011;8:221-226
Performance and Cognitive Flexibility
The change of cognitive flexibility, stress, and anxiety
during the game
There were significant differences in perseverative errors as
measured by the WCST and the time of TMTB between start-
ers and non starters (Z=3.32, p<0.01; Z=2.20, p=0.03, respective-
ly). The starter group had fewer perseverative errors (Z=3.32,
p<0.01) and more rapid TMTB times (Z=2.20, p=0.03), com-
pared to the non starter group (16.9±11.6 vs. 27.8±13.1; 83.0±
30.7 vs. 101.0 ±33.5, respectively) (Figure 1). However, there was
no statistical difference in the time of TMTA between starters
and non starters (Z=1.44, p=0.14) (Figure 1).
There were statistically significant changes in the scores of
the visual analogue scale for stress and anxiety before, dur-
ing, and after the game between starters and non starters
(F=4.34, p=0.01; F=6.61, p<0.01, respectively). The starter
group showed mild increasing slope of stress and rapid de-
creasing slope of anxiety, compared to non starter (Figure 1).
The correlation between cognitive flexibility, stress,
In the starter group, the perseverative errors measured by
the WCST (WCST_PE), were correlated with state anxiety
(r=0.68, p<0.01), time as measured by the TMTA (TMTA_SEC)
(r=0.44, p=0.04), and time as measured by the TMTB (TMTB_
SEC) (r=0.45, p=0.03). In the starter group, perseverative er-
rors were correlated with stress at the start of the game (r=0.77,
110105100 95 90 8580 7570 65
Figure 1. The change of stress, anxiety, and cognitive flexibility during competition (mean±0.95C.I.). Base, Mid, and Last: the score of stress
and anxiety in start, middle, and last of game. A: Comparison of perseverative errors between Starters and non-Starters, Z=3.32, p<0.01. B:
Comparison of TMTA-time between Starters and non-Starters, Z=1.44, p=0.14. C: Comparison of TMTB-time between Starters and non-Start-
ers, Z=2.20, p=0.03. D: Comparison of stress between Starters and non-Starters, F=4.34, p=0.01. E: Comparison of anxiety between Starters
and non-Starters, F=6.61, p<0.01. PE: perseverative error of Wisconsin Card sorting Test, TMTA & BSEC: Trail Making Test A and B time
DH Han et al.
p<0.01), but time was not correlated with stress and anxiety dur-
ing the middle of the game.
TMTB_SEC in starter group was correlated with stress and
anxiety at the end of the game (r=0.66, p<0.05; r=0.42, p<0.05,
respectively), while there was no significant correlation in non
starter group. The stress and anxiety estimated at the end of the
game was positively correlated with TMTB sec (r=0.55, p<0.01).
In non starter group, there was a positive correlation between
WCST_PE and TMTA_SEC (r=0.31, p=0.03). There was no
significant correlation between cognitive flexibility and stress
Cognitive flexibility in athletes
As we hypothesized, the starter group had better cognitive
flexibility and maintained it throughout the game as evidenced
by lower perseverative errors and the time on the Trail Making
Test (TMT Part B), compared to the non starter group. These
findings are in line with previous reports.9,26 Casteillo and Um-
ilta9 and Nougier et al.26 reported that volleyball athletes had
better ability to modulate attentional resources than non-ath-
letes. Enns and Richards10 suggested that highly skilled hockey
athletes showed more flexible attentional shifting than less
skilled players. In other words, highly skilled players could sh-
orten the time of cue-target interval, which replicated the pat-
tern seen previously.9,26 These specific findings in sports are line
with those in general situations.27 Beilock et al.27 reported that
the consequences of suboptimal performance, especially on ex-
aminations were associated with choking under pressure and
individual differences in working memory capacity.
Different from our expectation, there was no difference in
the times as measured by TMT Part A between starters and non
starters. The TMT Part A times in the starter group was not cor-
related with either stress or anxiety in middle of the game.
Those results are similar to those described by Kortte et al. ’s28
study. They suggested that TMTB would be more sensitive to
the deficit in cognitive flexibility than the ability to maintain a
complex response set. Specifically, those results indicated that
flexibility, operationalized as WCST percent perseverative er-
rors, was the only significant predictor of Part B performance.28
Stress and anxiety in athletes
Acevedo et al.s29 suggest that higher exercise intensities for
better exercise adherence and performance would make the af-
fect of athletes more negative. That research suggests heart rate
and exertion were significantly higher, and affective valence
was significantly less positive (p>0.01) for the higher-intensity,
shorter duration bout, with no differences in felt arousal (p>
0.05). Additionally, affective valence became less positive dur-
ing the higher intensity bout (p>0.01) but not the lower-in-
tensity bout (p>0.05).29 Current results showed that stress wo-
uld increase in the middle of the game in both starters and
non starters. However, the starter group demonstrated mild in-
creasing slope of stress and rapid decreasing slope of anxiety,
compared to the non starter group.
This means that the starter group controlled stress and anxi-
ety through the game. These are not surprising results and have
been reported in many studies.30,31 Hardy30 reported that stress
would debilitate the function of psychological skills (goal-set-
ting, imagery, self-talk, and relaxation skills) which were th-
ought to enhance the performance of athletes. In the compari-
son of basketball athletes with higher (debilitative) or lower
(facilitative) perceptive anxiety, the facilitative athletes would be
less discouraged and have less stress than debilitative athletes.31
The correlation of cognitive flexibility, stress, and
In starters, high levels of cognitive flexibility were correlat-
ed with lower stress at the start and end of the game. As men-
tioned in the Introduction, the modulation of cognitive flexibil-
ity and complex tasks requiring cognitive flexibility impact
performance.4,7 Differentiation is the ability to recognize mul-
tiple dimensions embedded in a perceived domain and taking
different perspectives when considering the domain.32 Integra-
tion is the ability to perceive trade-offs in terms of the strengths
and limitations of coping strategies.33 Actually, Silva and Apple-
baum34 reported that high ranking marathon runners effective-
ly employed associative and dissociative techniques as a cogni-
tive strategy during marathon racing.
Specifically, there was a positive correlation between stress
and anxiety of starters at the end of a game. Based on the report
that mental stress was associated with state anxiety,35 we cau-
tiously suggested that cognitive flexibility in starters would con-
trol anxiety as time passed which allowed the athletes keep their
play stable when confronting stressful and anxious situations.
First, the current study which used soccer athletes as subjects,
did not consider cumulative sub-concussive head trauma when
estimating cognitive function. Although there were controver-
sies, Rutherford et al.17 suggested that the total amount of head-
ing done by soccer athletes would affect the results of Wiscon-
sin card sorting category. Second, there are many factors which
increase the stress of athletes during exercise and competition.
The relationship between stress and sports performance has
been thought to be an extremely complex one and associated
with the nature of the stressor, and the cognitive demands of
the task being performed.36 Moreover, Deveney et al.37 demon-
strated that divergent styles of responding to emotional infor-
226 Psychiatry Investig 2011;8:221-226
Performance and Cognitive Flexibility
mation would contribute to protection from depressed mood.
Current results suggested that better cognitive flexibility
would enhance human performance by modulation of the anxi-
ety and stress during competition. This study hopes to contrib-
ute substantive knowledge about the role of cognitive flexibili-
ty in the performance accompanied by stress and anxiety.
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