The measurement of arousal by the means of electrodermal activity during an actually performed ...

73 Pages·2012·1.94 MB·English

by  Melanie Knufinke

The measurement of arousal by the means of electrodermal activity
during an actually performed balance beam routine and
observational learning of the same routine

Melanie Knufinke
Bachelor Thesis

Faculty of behavioral sciences
University of Twente
Enschede, 01 February 2012
Subject: Bachelorthesis HFM
First Supervisor: Dr. Matthijs Noordzij
Second Supervisor: Dr. Elger Abrahamse

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Summary
The aim of this study was to gain insight into arousal patterns of gymnasts during
actual performance (AP) and observational learning (OL) of a beam routine. Arousal was
measured by the means of electro dermal activity (EDA) with a wireless, logging sensor. A
second aim was to get insight in EDA recordings obtained from different anatomical sensor
locations (wrist, forearm, palm). EDA was measured three times when five regional level
gymnasts were performing their beam routines, as well as during OL of these routines. EDA
was recorded from the wrist and forearm. During the last OL condition, EDA was recorded on
the palm. A control group was formed of 11 non-gymnasts to examine whether arousal
patterns are due to the stimulus or other factors. Non-gymnasts participated in the OL
condition as well when EDA was measured at the palm. Women artistic gymnastics (WAG)
employ short intervals of high skilled and demanding exercises eliciting varying levels of
arousal. Arousal regulation has become important to enhance performance and prevent injury
in WAG and OL is often used to regulate arousal. Comparison of arousal patterns during OL
and AP revealed higher skin conductance responses (SCR) during AP. Sensors attached to the
forearm during AP had less motion artifacts and showed comparable EDA sensitivity to the
sensor attached to the wrist. During OL, the palm has shown to be the most sensitive location
when measuring EDA. Although correlations between the conditions and locations were low,
some similar trends have been found in EDA waveform. More appropriate statistical methods
are needed to further analyze arousal in both conditions. Recommendations for further
research are outlined in the discussion. This study gave some insight into arousal patterns
during AP an OL and has significant importance in fields as sport psychology,
psychophysiology as well as sport physiology.

Keywords: Arousal, electrodermal activity, SCR, observational learning, women artistic
gymnastics.

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Samenvatting
Het doel van deze studie was om inzicht te krijgen in arousal patronen van turnsters
tijdens een daadwerkelijk uitgevoerde balkoefening (engels: actual performance, AP) en
observational leren van dezelfde oefening. Arousal (opwinding) werd gemeten aan hand van
huidgeleiding (engels: electrodermal activity, EDA) met een draadloze sensor die opnames
meteen kan opslaan. Een ander doel was om inzicht te krijgen in huidgeleiding opnames, die
genomen werden op verschillende anatomische locaties (pols, arm, palm). Huidgeleiding
werd drie keer gemeten bij vijf turnsters die hun balkoefening op regionaal niveau turnden en
tijdens observational leren van dezelfde oefening. Huidgeleiding werd aan de pols en arm
gemeten tijdens de daadwerkelijk uitgevoerde oefening. Alleen tijdens de laatste OL conditie
werd huidgeleiding aan de palm gemeten. Een controlegroep van 11 niet-turnsters was
opgezet om te onderzoeken of patronen in opwinding ook echt door de stimulus (Balk
element in AP en OL) veroorzaakt werden en niet door andere, niet relevante stimuli. De niet-
turnsters participeerden alleen in de OL conditie waarbij huidgeleiding uitsluitend aan de
palm werd gemeten. Turnen was gekozen als relevante sport omdat het korte, intensieve en
inspannende momenten met hoge moeilijkheid heeft, die vaak tijdens het uitvoeren tot hogere
opwinding leiden. Het reguleren van deze opwinding heeft belangstelling gevonden in de
turnwereld om prestaties te verhogen en blessures te voorkomen. Observational leren wordt
daarbij vaak als middel gebruikt. Het vergelijken van opwinding in allebei de condities heeft
hogere ‘skin conductance response’s’ (SCR’s) tijdens AP gevonden, vergeleken met OL.
Sensoren die EDA aan de arm hebben gemeten hadden minder bewegings-artifacten, dan
sensoren die aan de pols hadden gemeten. Tijdens OL bleek de palm het meest sensitief te
zijn voor EDA en daarom de betere plek om EDA te meten. Hoewel correlaties tussen de
condities en meetlocaties erg laag waren, konden er wat overeenkomsten in EDA-golven
worden gezien. Het onderzoek heeft getoond dat beter statistische methoden nodig zijn om
goede conclusies te kunnen trekken. Aanbevelingen voor vervolgonderzoek worden in de
discussie behandeld. Deze studie heeft enig inzicht gegeven in patronen van opwinding
tijdens AP en OL en heeft daarom significante waarde voor gebieden als sportpsychologie,
sportfysiologie, psycho-fysiologie en sport fysiologie

Trefwoorden: Opwinding, huidgeleiding, SCR, observational learning, turnen.

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Contents

1. Introduction 5
1.1 Women Artistic Gymnastics (WAG) 5
1.2 The concept of arousal 7
1.3 Electrodermal activity (EDA) as a mean to measure arousal 8
1.4 Observational learning (OL) 9
1.5 Hypotheses 11

2. Method 14
2.1 Participants 14
2.2 Design and procedure 15
2.3 Instrument and Task 17
2.4 data analysis 20

3. Results 21
3.1 Visual analogue scale 21
3.2 Quantity of mean SCR 22
3.2.1 Mean SCR quantity during AP and OL 23
3.2.2 Habituation effects during OL 23
3.2.3 Palm measures 25
3.2 Mean amplitude of SCR 26
3.3.1 Mean amplitude during AP and OL 26
3.3.2 Habituation effects during OL 27
3.3.3 Palm measures 29
3.4 Gymnasts - non-gymnasts 30
3.5 Correlations 32
3.5.1 Correlations of wrist and forearm EDA recordings during AP 32
3.5.2 Correlations of EDA recordings between AP and OL 34
3.6 Motion artifacts 36

4. Discussion 38
4.1 Limitations 45
4.2 Conclusion 46

Acknowledgements 38
References 49
Appendix 52

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1. Introduction
The aim of this study is to measure arousal by the means of electrodermal activity
(EDA) in a high demanding setting outside of the laboratory with a new wireless, logging
sensor. Women artistic gymnastics (WAG) was chosen as sport, because of its short intervals
of high skilled and demanding exercises. The nature of the sport and the importance of
arousal regulation in injury prevention and performance enhancement will be outlined in
detail. Many techniques such as imagery and observational learning (OL) have already been
employed to regulate arousal and enhance performance. Due to the significant of OL and its
benefits concerning arousal regulation, is the aim of this study to examine arousal in (1) a
physical demanding task, namely during a balance beam routine, and (2) during a cognitive
task, namely observational learning of the same routine. Results of this study can offer deeper
insight into arousal patters during an actual performed task and observational learning of the
task and has therefore significant importance in fields as sport psychology, psychophysiology
as well as sport physiology. To the best of my knowledge, arousal has never been measured
before by the means of EDA during a beam routine or a comparable intense physical activity.
Due to the novelty of the method this study is meant as a viability study and has an
explorative character. The focus lies on comparison of arousal patterns during two conditions
– actual performance (AP) of a balance beam routine and OL of the same routine. Thereby
EDA was measured on three different locations, the wrist, forearm and hand-palm, to
determine the best location for arousal measures during physical exercise. The results and its
implications will be discussed at the end of this paper.
1.1 Women Artistic Gymnastic (WAG)
Women artistic gymnastics (WAG) is known for short intervals of highly demanding
exercises requiring high concentration, alertness, as well as emotional- and arousal control
(Johnson, 2009). Especially individual- and jury sports such as WAG denote high rates of
severe injuries (Johnson, 2009; Caine & Nassar, 2005; Kolt & Kirkby, 1999) and often use
OL to enhance health and performance. Common stressors in WAG are fear of injury, the
subjective scoring system, social factors such as the presence of an attentive audience,
performing skills under (time-) pressure, wishing to perform well to please someone, and the
perceived importance of the event (Tremayne & Barry, 1988). The stressors that are found
within WAG reveal that emotion, especially social pressure, anxiety and fear of injury, are
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important factors that influence the performance as well as the well-being of the gymnast.
Therefore ways of measuring these factors and techniques to regulate them are strongly
needed. A study of Poh, Swenson and Picard (2010) found stress to disrupt the balance of the
autonomous nervous system and therefore to increase the sympathetic tonus, resulting in
higher measurable arousal (Poh et al., 2010). These results lead to the assumption that
measuring arousal patterns by the means of EDA during WAG performance is possible but
also challenging.
Many authors stress the importance of optimal arousal levels during WAG routines
(Tremayne & Barry, 1988). Treymayne and Barry (1988) concluded that gymnasts with low
levels of anxiety could easier ignore distracting, irrelevant stimuli and focus with little effort
on relevant stimuli during performance, which is quite important during gymnastic routines.
Optimal arousal models state that high arousal has a negative effect on performance, whereas
reversal theories of arousal state the opposite, that high positive arousal enhances
performance (Perkins, Wilson & Kerr, 2001). Perkins et al. (2001) concluded that it depends
on the subjective rating of arousal as rather positive or negative, if a performance decreases or
improves by arousal. High arousal, combined with a positive motivational state can enhance
performance in tasks with maximal motor strength; the reverse was found when arousal was
combined with a negative emotional states. The above mentioned stressors affect arousal
away from an optimal level, resulting in a loss of focus by the gymnasts (Tremayne & Barry,
1988). Cottyn, Clercq, Pannier, Crombez & Lenoir (2006) already mentioned the significance
of anxiety in gymnastics, especially when executing elements of high difficulty on a 10 cm
wide balance beam (BB) of 125 cm height. The nature of a beam can elicit anxiety and stress
in gymnasts and arousal regulation is expected to improve performance and well-being of the
gymnast. Because of the demanding nature of a beam routine, the balance beam has been
chosen as event to measure arousal in this study. It is necessary to examine which aspects of
the beam routine elicits higher arousal amplitudes and whether these are due to positive
feelings as result of a successful performed element, or due to anxiety and stress because of a
high demanding element that is to be executed.
Winfrey & Weeks (1993) concluded that self-modeling of gymnasts enhances the
gymnasts’ ability to assess their own balance beam performance realistically. The concept of
self-modeling will be outlined in detail later on. If self-modeling can be employed to
realistically access one’s actual performance, it would be interesting if the same arousal
patterns can be found during self modeling, as for example during observational learning of a
beam routine.
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The significance of arousal within WAG and the need for more research concerning
this issue as well as on coping strategies, as e.g. arousal regulation, have become clear. The
concept of arousal with a few underling theories will be described in the next section.
1.2 The concept of arousal
In general terms the level of arousal refers to a global state of the mind. This state of
mind can range from a continuum from very low, as when a person is asleep, to very high as
when a person is fully awake. Arousal is an indicator of brain activity and measurable on a
(neuro-) physiological-, psychological- and behavioral level. It is not the same as anxiety or
stress, which both have negative connotations, because arousal cannot specify the valance of
an emotion. Arousal can be positive, negative or neutral as it has often been visualized in
many dimensional theories that illustrate emotions on a continuum that varies on two or more
axes, mostly arousal and valance. Arousal can be high as a result of both, extreme positive- or
negative emotions. The vector- and circumplex model arrange cognitive and affective states
on such dimensions, arousal and valance, which rank from low to high and from positive to
negative, respectively (Purves, Brannon, Cabeza, Huettel, LaBar, Platt & Woldorff (2008). By
the means of these models, several emotions can be classified to valance and level of arousal.
Several arousal theories aimed to address optimal levels for specific kinds of sports
(Perkins et al., 2001). The ‘Inverted U theory’ by Yerkes and Dodson, states that too high or
too low levels of arousal and anxiety cause a person to perform poorer compared with
performance at a medium level of arousal. But opinions still differ concerning the optimal
zone of arousal. Perkins et al. (2001) claim that the motivational state determines if high
levels of arousal strengthens or weaken performance in motor tasks. This theory is most
accepted nowadays.
Regardless of which arousal level is found to be optimal for WAG, it would be
interesting to determine whether OL can modify and improve negative emotions and
moderate levels of arousal to enhance concentration and further prevent injury in WAG as
proposed by Cumming et al. (2005). For that purpose it is important to first of all measure
arousal during an actual performed routine and to compare the patterns to arousal patterns
during OL of such a routine. If it possible to measure arousal by the means of EDA in both
conditions, and if both conditions show some similar arousal patterns, EDA can be employed
as a valid method to analyze the effects of arousal regulation by the means of OL and its
effect on physical performances.
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Scarcity of research exists concerning the contribution of arousal levels during artistic
gymnastics performances and OL conditions of WAG routines due to a lack of applicable
research methods and technologies. Up to know, research concerning arousal by athletes was
restricted to heart rate and qualitative approaches and little event related sampling (i.e. related
to a particular isolated gymnastic element) has been done yet (Cottyn, et al., 2006; Cottyn,
Clercq, Crombez & Lenoir, 2008; Tremayne & Barry, 1988). The following section will
describe a new technology, the Affectiva Q™ Sensor that can measure arousal by the means
of EDA outside the laboratory.
1.3 Electrodermal activity (EDA) as a mean to measure arousal
Electrodermal activity (EDA) refers to changes in the skin conductance at the skins
surface. These changes are an indirect indicator of activity in the sympathetic branch of the
autonomous nervous system and used in various clinical and nonclinical settings. EDA can be
measured as a result of eccrine sweat gland activity (Turaclar, Erdal, Arslan, & Yildiz, 1999).
Activity of the sympathetic branch is associated with emotion, cognition and attention
(Critchley, 2002). Therefore conditions such as anxiety, high physical arousal or high
cognitive work load can increase the sympathetic tonus and change the peaks of the EDA.
This physiological measure could give a more detailed, event related and specific
insight into arousal patterns during actual performance and observational learning of a WAG
routine that have never been explored before. Arousal measures obtained by the means of
EDA can give no specification of valance of a specific emotion as explained before. To
determine whether arousal was higher due to a negative stressor as anxiety or a positive event
as successfully performing an element, additional qualitative approaches are necessary.
Observations and questionnaires concerning mood and emotional states are commonly used to
determine the valance of physical arousal.
Recently a new mobile and easy-to-wear device was developed to measure EDA,
called the Affectiva Q™ Sensor. New areas of research can be explored, because the
Affectiva Q™ Sensor can measure activity of the autonomous nervous system in challenging,
everyday life settings and is no longer restricted to laboratory settings (Poh et al., 2010;
Hedman, Wilder-Smith, Goodwin, Poh, Fletcher, & Picard, 2009). To examine the feasibility
of EDA measurements in a highly intensive and extreme setting out of the laboratory, as a
beam routine in WAG, is one of the goals of this study. Results are regarded as valid when
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EDA waveforms show actual skin conductance responses instead of flat lines. Little electrical
noise and few motion artifacts are other validation criteria in this study.
1.4 Observational learning (OL)
Observational learning (OL) is beside actual performance (AP) of a beam routine, the
second condition in which arousal is measured in this study. This section briefly outlines the
benefits of OL and the way it is used in sports.
Observational learning, also known as social learning or modeling, is learning that
occurs by the means of observing others executing novel, to the observer, unfamiliar tasks. It
can be seen as learning by observing and reproducing behavior of an expert model. It has its
origin in the social learning theory by Bandura (Bandura, 1991), who states that four stages,
attention, retention, motor reproduction and motivation, need to be involved for successful
OL .
Even though OL is a commonly used technique on recreational- and elite level in
nearly all kind of sports, it gets employed in different ways. Competitive and recreational
athletes use OL to a lesser extent than school-team (varsity) athletes do (Wesh, Law & Hall,
n.d.).Varsity athletes use OL mainly to maintain their level of performance and to promote
health, instead of using it mostly for performance enhancement (West et al., n.d.).
A further distinction can be made between individual and team athletes. Individual
performance is characterized by the fact that individuals perform their actions independently
of others. If a team score (e.g. for a group of gymnasts from one country) needs to be
calculated all individual scores will be summarized to a total score. In contrast, team
performance is defined as performance in which individuals need to coordinate and integrate
their action with the actions performed by others (Wesh et al, n.d.). Individual athletes more
often use OL for skill learning whereas team athletes use OL more for learning strategies that
can be employed during games and competitions with others (Wesh et al., n.d.). Therefore
gymnasts, who are individual athletes, can be expected to use OL to enhance their general
skill level.
Benefits of OL can be found in cognitive and motivational functions, where cognitive
benefits have been found to be most common. Cognitive functions can be categorized in
enhancing skill and strategy (Cumming, Clark, Ste-Marie, McCullagh, & Hall, 2005; Wesh, et
al., n.d.). Enhancing performance as result of OL is categorized as a motivational function
rather than as cognitive function. Imagery, a closely related technique, is used more often than
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OL to enhance motivation and goal setting in sports (Cumming et al., 2005). These results
reveal that an OL task should involve evaluation on skills and strategies. In the case of
gymnasts, strategies can better be translated to techniques.
Besides positive effects on performance, OL has been found to positively influence
psychological variables as well. McCullagh and Weiss (2002) claim that OL is a
psychological method to modify thought, emotions, and behavior in athletes. Ives, Straub and
Shelly (2002) have used video recordings to improve emotional and motor behavior as well as
player-coach communication in athletes. Wulf et al., (2009) claim that observational practice
enables a learner to accomplish processing that could not occur during actual physical
practice. Athletes are also found to use OL to regulate their arousal levels and other mental
states that in turn can enhance performance (Cumming et al., 2005). A variety of
psychological strategies are used nowadays to optimize athletic performances. Especially for
explosive athletic performances as e.g. shot-put, javelin, weight-lifting and sprinting, where
maximal motor activity during short time intervals is significant, mental preparation
strategies, that additionally integrate arousal regulation, are important to enhance performance
(Perkins, Wilson & Kerr, 2001). Therefore OL can be regarded as an important tool for WAG
and even seem to effect emotion and arousal in either way.
Despite the abundant use of OL in sports and the masses of research concerning this
issue, it lacks a well defined definition. OL of motor skills, which is an aspect of this study,
can be divided into two areas. The first area is the observation of a model which allows
imitation and understanding of modeled behavior. The second component is self-observation
by which a person can actively regulate own motor learning and performance by observing
oneself (Ferrari, 1996). The main focus in this study will be on the second area, self-
observation, also often referred to as self-modeling. The aim of this study is not to improve
performance in first instance, but to purely measure arousal during watching oneself back
performing a demanding physical task. Ferrari (1996) clearly states that individuals need to
self regulate their own learning process to learn or improve motor skills. Especially in WAG
it is important to closely examine own movements to regulate and adapt motor behavior. This
process of observing and reflecting on the own learning process leads to more confidence and
is important for motor improvement (Ferrari, 1996). Dowrick (1999) summarized seven
factors that enhances learning, well-being and performance by the means of self-modeling: (1)
clarifying goals and outcomes; (2) demonstrating a positive self image; (3) reminding of
previous competence in performance; (4) repeating competent observations in role-play; (5)
observing one`s skills applied in a new setting; (6) producing anxiety free behavior or
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