Lateral asymmetry of emotional arousal as a biomarker of attributional style during darts competitions

According to the Multiple Arousal Theory, electrodermal activity (EDA) is not uniform across the body. However, the psychological meaning of a left or right sided EDA dominance is not clear. We explored EDA lateral asymmetry as a psychophysiological marker of optimistic and pessimistic attributional style regarding success and failure in a darts competition. Bilateral EDA pattern of 230 throw actions of a competing pair was measured by Obimon EDA including accelerometer measurements of movements. First, we con�rmed that lateral asymmetry can be measured reliably based on EDA data from both wrists. Second, we assessed attributional styles related to lateral asymmetry based on 80 individual throw actions. We recorded participants’ expectations regarding their upcoming throw performance, and their attribution of success and failure. Seligman’s de�nition was used to classify throw attributions as optimist (internal cause attributed to success, or external cause ascribed to failure) or pessimist. The ratio of optimist and pessimist attributions was signi�cantly different for throw actions with right or left sided EDA dominance (p=0.001). Optimistic attribution characterized 84% of right-sided EDA throws, and pessimist attribution was present in 63% of left-sided EDA throws. We replicated these �ndings based on 50 throw actions from 10 more individuals (p=0.034). We conclude that wrist EDA can be reliably measured during physical movements, such as throw actions in a darts game. Lateral EDA asymmetry is a consistent psychophysiological marker of the attitude towards success and failure in a competitive setting. Results underly the psychophysiological relevance of bilateral arousal assessment.


INTRODUCTION
The Galvanic skin response to stimuli evoking arousal was discovered more than 150 years ago.
Measuring eccrine sweat gland activity elicited by the activation of the autonomous nervous system is relatively easy.With the use of wearable sensor technology EDA is even easier to utilize in psychophysiological studies (Tronstad et al., 2022).Thus, electrodermal activity (EDA) has been utilized in numerous studies to date.Listening to music, for example is related to a prominent change in emotional arousal (Salimpoor et al., 2009).Clinical implications of electrodermal activity are evident.Electrodermal hyporeactivity, for example is a valid marker for both depression and suicidal risk (Sarchiapone et al., 2018;Thorell et al., 2013).Reduced skin conductance level in response to breathing manipulation suggest a loss of functionality of the autonomic nervous system in bromyalgia syndrome (Reyes del Paso & de la Coba, 2020).Applications using EDA-based measurements have been used in both every day and clinical practice.Li and colleagues (2022), for example have identi ed the phasic component of electrodermal activity as a sensitive marker of driver state management and utilized this measure in takeover-safety predictions in applications for automated driving systems.Rosalind Picard and her colleagues have identi ed autonomic footprints that could provide reliable biomarkers to identify patients with epilepsy who are at risk of sudden unexpected death (Poh et al., 2012)and have developed a wearable EDA-based tool to detect possible convulsive seizures, alerting caregivers instantly (Empatica, Embrace 2).

Bilateral asymmetry in electrodermal activity
Mostly sympathetic activity of the autonomic nervous system is involved electrodermal activity, with both ipsilateral and contralateral pathways involved (Boucsein, 2012).Interestingly there is quite an uncertainty about both underlying mechanisms and function of this psychophysiological marker of the arousal state.One of the central issues is whether different body locations respond differently to certain stimuli, and if these physiological differences are psychologically meaningful or not.
Dawson's "One True EDA" Theory (Dawson et al., 2007) corresponds to the general view in most of the literature stating that the electrodermal responses are general and thus, EDA activity measured on one single location represent the arousal state of the whole body.In contrast to this view, the "Multiple Arousal Theory" (Picard et al., 2016) argues that in emotionally aroused situations eccrine glands on the different body parts produce distinct amounts of "emotional sweating", thus resulting in different EDA levels.To prove this theory, Picard and colleagues recorded EDA from a single person throughout daily activities, with multiple stressful events.During these events she reported asymmetry between EDA levels measured on the left and right side of the body.
It is also debated whether lateral EDA asymmetry is psychologically meaningful.Studies assessing the psychophysiological role of bilateral EDA show contradictory results.Bjørhei and colleagues (2019) reported that although bilateral EDA levels might be asymmetric, they do not display signi cant difference in their pattern between two psychologically distinct conditions, as measured by tasks with high and low-stake stressors.On the other hand Kasos and colleagues (Kasos et al., 2018) found that short, 7-second musical segments with various emotional categories resulted in measurable differences of lateral asymmetry on the two palmar areas.Fear, peacefulness and sadness evoked right hand laterality, while happiness elicited dominance of the left hand EDA.In a more recent study Kryklywy and colleagues (Kryklywy et al., 2022) stimulated either the right or the left hand of participants electrically in both ipsilateral and contralateral ways.They reported lateralized EDA response aroused by limb-speci c stimulation, suggesting that the autonomic nervous system prepares the body to a side-speci c action, not just to a general " ght or ight" response.
Several ndings suggest psychophysiological relevance of lateral EDA asymmetry, providing a novel direction to assess bilateral EDA and provide more insights to the role of EDA asymmetry.

Electrodermal activity, performance and attributional style in sports
Due to recent technological improvements in EDA measurement application in sport-related situations have become relevant.Posada-Quintero and colleagues (2018)demonstrated that EDA is sensitive to cognitive stress underwater.To understand connections between EDA and different performance types within the multi-action plan model Bertollo and colleagues conducted an experiment with national-level sports athletes.Optimal-automatic, optimal-controlled, suboptimal-controlled, and suboptimal-automatic performance was investigated during more than 100 trials (Bertollo et al., 2013).They showed better performance linked to controlled trials (with higher consciousness of the action) as compared to automatic trials (with lower consciousness of the action).Information from the entire spectrum of psychophysiological and behavioral features linked to the actual performance was important to develop and implement biofeedback and neurofeedback techniques aimed at helping athletes to identify individual levels of optimal functioning and enhance performance.Although EDA seems to be an important biomarker of physical training and competition, bilateral EDA measures have not been investigated before.
Optimism and pessimism are parts of our everyday life; however, they play a crucial role in sport performance.According to Hecht, both hemispheres are involved in optimistic or pessimistic thinking, yet the right-hemisphere is more arbitrated in pessimistic thinking, whereas the left hemisphere is more mediated in optimistic thinking (Hecht, 2013).Numerous studies investigated how the optimistic attributional style affects performance.Global negative attributional style was related to poorer performance of academics (Houston, 2016).Many researchers claim that optimists outperform pessimists, but there are only a handful of studies which actually proves this assumption.The Attributional Style Questionnaire, or ASQ, developed by Peterson et al. (1982) is the most widely used measure of the optimist or pessimist attributional style.As an example, a university swimming team was assessed before a championship.They found that the optimistic swimmers had less bad results than expected (Seligman et al., 1990).Gordon and his team (Gordon, 2008) reinforced these ndings with a study on soccer players, where a signi cant positive relationship was found between athletic performance and the ASQ measure of optimism.Interestingly there was no signi cant performance difference between these two groups during a subsequent win, however, when loosing, optimistic soccer players demonstrated better performance as compared to losing pessimists.
It is obvious to investigate if there is any relation between atribution style and EDA lateral asymetry in competitive situations, such as in sport competitions.Interestingly, no previous studies tested this reserch question.Goal of our present study was to investigate if lateral electrodermal asymmetry could serve as a psychophysiological marker of optimistic or pessimistic attitude towards evaluating one's own performance during a darts competition.

An overview of the four studies and participants
Table 1 presents the main characteristics of the four studies performed and the participants in each.A total of 15 participants were recruited to take part in one-to-one or 4 subjects/group competitions.Data of three participants (Subject number 1., 14. and 15, labeled by grey color in Table 1) were excluded from the analyses, for the lack of valid EDA measurement or being left-handed.The reliability studies were based on wrist measurements from Subject 2. In Study 1 the EDA electrodes were reattached twice to see if laterality changes due to the replacement of electrodes (see Fig. 1).In Study 2 we asked this participant to throw with alternate hands to detect if there is any effect of the throwing hand movement (see Fig. 2).
In the initial study (Study 3) Subject 2 (male) and Subject 3 (female) engaged in a one-to-one darts competition.A single dart was thrown 10 times by one of the players, followed by 10 throws of the other player in each set.A total of 4 sets were accomplished by each player.
The replication study (Study 4) aimed to investigate shorter competition assays in a group setting of 4 participants.They were recruited as part of a university course requirement.Students were instructed to gather their own groups of four people, representing both sexes equally.Each participant performed 5 throws in a single set one after each other.
Throws were performed by the right hand of the players except in Study 2, where half of the sets were made by the right hand and the other half by the left hand of Subject 2. In all studies participants had a chance to warm up before the darts game by a few minutes of practice throws.

Materials and procedure
The study protocol was approved by the Institutional Ethical Board of the Eötvös Loránd University (approval number: 2018/330-3).Participants were recruited via convenience sampling.
After lling out informed consents, electrodes and EDA measuring devices were placed on their left and right wrists.We collected bilateral EDA during the entire session (presented in Figs.1-3 and Supplementary materials, Figure S2).Handedness was determined by the Hungarian adaptation of the Edinburgh Handedness Questionnaire (Old eld, 1971, see shared software at: http://www.brainmapping.org/shared/Edinburgh.php).
Subjects threw darts in a predetermined order as instructed by the experimenters.Question and answers before and after each throw were sound recorded for later analysis (see: "De nition of attribution style" below).
We used a 40 cm diameter magnetic darts board, and 9 cm long darts.The board was divided to 20 equal sections worth different points each, and rings marked single, double, and triple areas along the center "bull" and "bull's eye" according to standard scoring Wikipedia contributors, 2021, July

De nition of lateral asymmetry
Raw EDA values as measured on the right (red lines) and the left wrist (blue lines) are presented at each gure separately (see Figs. 1-3 and supplementary Figures S1 and S2.)A left sided EDA dominance was present, if EDA values on the left wrist are higher throughout the darts session.A right sided lateral dominance was present if on the contrary, the left wrist EDA data was higher.Laterality was not obvious only in 6 cases of the total of 230 throws.These ambiguous cases were the 1st throw of Subject 7 (see Fig. 3) and all the 5 throws of Subject 13 (see supplementary Figures S1).

De nition of attributional types
One of the three dimensions of Seligman's questionnaire (Peterson et al., 1982) were used to determine if the participant' s opinion of their own performance could be de ned as an optimistic or a pessimistic attitude toward the speci c throws.This dimension was based on whether the participants had external or internal reasoning about their performance.The participants were asked before each through about their expectation, as well as after each throw to explain their better or worse performance than expected.
The attributional style was determined by two independent evaluators based on the recorded explanations of the throwers.The throw was regarded as "good" if the resulting point was higher or equal to expectations, while it was "bad" if the result was lower than expected.An internal explanation of a good throw or an external explanation of a bad one was classi ed as an optimist attribution type (see examples in Table 2).On the other hand, if a person had an external explanation when a good throw occurred or blamed themselves for a bad throw, they were classi ed as having a pessimist attribution style.

Data exclusion
The initial sample resulted in 80 responses of which 71 were judged identically by the two evaluators (88% consistence).In 9 cases where the two independent evaluators judged differently the explanations of the participants, they discussed their opinions, and a consensus was formed between them for each debated explanation.30 cases were judged as uncategorizable by both evaluators as they were not informative enough to determine the attribution style.Therefore 50 throws with unambiguous judgements and valid asymmetry were analyzed in the initial sample (Study 3).
In the replication sample throws and answers of 10 participants have been analyzed for attribution type.
Here evaluators showed 87% initial consistency, and similarly to the previously described procedure nalized a consensus for each of the cases (including 10 explanations that were not categorizable for attribution type).As noted before EDA data of 6 throws did not have a clear asymmetry, thus 34 throws with unambiguous judgements and valid asymmetry were analyzed in the replication sample (Study 4).

Data analyses and statistics
Raw acceleration and EDA data with automated time stamps based on the Network Time Protocol (NTP) were extracted from the memory of Obimon EDA devices.The start of the darts competition and the exact time of the throws were determined with the use of the sound recordings (also synchronized via NTP): the audio recordings provided an anchor for the exact moment when the dart hit the board.The time interval of each throws varied.They are labeled by gray vertical lines on Figs. 2 and 4, as well as Supplementary Figures S1and S2. 2. We expect to detect lateral asymmetry of electrodermal activity in the time frame of the competition.
3. Laterality of EDA (right or left dominance) characterizes each throw and may be used to implicate psychological state (attributional style) of the players.

Reliability considerations of lateral asymmetry during darts competition
In studies 1 and 2 we aimed to test reliability of EDA measurements using data from two one-to-one dart competitions.We investigated the effect of both electrode re-attachment and wrist movements on EDA patterns, focusing on lateral asymmetries.

Re-attachment of electrodes does not change EDA asymmetry
In study 1 Subject 2 was asked to play a 3-set competition with Subject 1. Bilateral EDA measurements were collected only from Subject 2 only (the role of Subject 1 was to ensure the context of a competition).
In between sets both the Obimon devices and the electrodes were detached from both wrists of Subject 2 and then re-attached to approximately the same areas.We assessed if there were any laterality changes after re-attaching the electrodes.
Skin conductance values of Subject 2 are displayed for the three sets.The red line represents right wrist skin conductance in µS, and the blue line represents left wrist EDA during the 40-minute competition.Set 1, 2 and 3 labels highlight the time frame of a couple of minutes, when Subject 2 was throwing the darts.These periods are followed by waiting times for Subject 2, indicated by "partner plays" labels.After the darts game, Subject 2 played the piano.The "re-attach" labels signal the two short time periods (28 and 35 seconds), when devices and electrodes were taken off from both wrists, and then devices were reattached using new electrodes.
Figure 1 shows an increase of skin conductance levels of both wrists with an apparent right-sided laterality throughout set 1 and in the rst waiting period.After the rst re-attachment skin conductance level for both wrists started from approximately the same values as before the reattachment.In set 2, skin conductance level continued to raise with a right wrist dominance throughout the 10 throws.While partner played after set 2, Subject 2 had large negative peaks on the right wrist presumably resulting from hand and body movements as walking around.For the end of the waiting period, a right-hand dominance appeared again.
After the second re-attachment of device and electrodes there was a large, 22 µS drop in the skin conductance level of both wrists due to unknown reasons.The lateral asymmetry of EDA, however, remained the same: the right wrist EDA was higher than the left wrist EDA throughout set 3. In contrast to set 3, the bilateral EDA values were nearly equilibrated during the last waiting period.After the game Subject 2 played the piano to attest emotional arousal in a more relaxed state of mind with active wrist movements.During this time (starting at about the 36th minute, see Fig. 1) asymmetry of laterality disappeared.

Switching throwing hands does not change EDA laterality
Since wrist movements are a clear obstacle of EDA measurements according to the literature, we tested in Study 2 whether switching the hand that the player throws with has any effect on lateral asymmetry.
Subject 2 was playing another darts competition with Subject 1, but once again, only EDA data of Subject 2 was assessed.Both players threw 6 sets each, but Subject 2 was asked to switch throwing hands in between set 3 and set 4, and once again in between set 5 and 6.All sets lasted approximately 2-minute, with a 4-minute resting time interval in between.
Figure 2 shows EDA measurement results during throws of set 3 and set 4 as an example of EDA asymmetry in EDA measurements of the two wrists.Skin conductance values measured on the right wrist are presented by the red line and left wrist measurements are highlighted with blue.One could notice that fast negative EDA peaks on the right wrist characterized each of the ten throws at the moment of throw when the throws were made by right hand (see: Fig. 2A).These EDA negative peaks, however, were not detectable if the left hand was used to throw (see Fig. 2B).Nevertheless, considerably higher right wrist EDA levels in both parts of Fig. 2 suggest that Subject 2 was lateralized to the right, regardless of the hand used for throwing.A similar, right dominant EDA pattern was detected in all the other sets (data not shown), independently from the throwing hand.

Portraying lateral asymmetry during darts competition
In the initial sample (see "Study 3" in Methods section) two, similar age, mixed gender participants (Subject 2 and Subject 3) competed in a one-to-one setup.Raw EDA data of Subject 2 during one of his

EDA laterality indicates players' attribution style towards their ownperformance
We also collected verbal feedback about participants' opinion about their each throw.They guessed their next performance (points) right before throwing, and after the throw they reported about their performance as well as the cause of their result compared to their guess.Based on these data, we determined each participant's attribution style as either optimistic or pessimistic towards their own performance.This dimension was determined on whether the participants had external or internal reasoning towards their performance.The results were evaluated by throws.The outcomes of Table 2 show us outcomes of both the initial (Study 3) and replication study (Study 4).People who were lateralized towards their right wrist had more optimistic responses in overall than those who were lateralized towards their left wrist.This was the case in 84% of the explanations after the throw in the initial study and 61% in the replication study.Accordingly, participants who were lateralized towards their left were more likely to have a pessimistic explanation (initial study: 63%, replication study: 75%).The Chi-square test revealed signi cant difference in both studies (initial study: p = 0.001, N = 50; replication study: p = 0.034, N = 34).

Reliable measurement of EDA lateral asymmetry during a competition
There is a common belief that artefacts caused by physical movement invalidate EDA measurements.
Even though there are multiple solutions around this problem in long term measurements (Can et al., 2019;Taylor et al., 2015) researchers often choose not to measure at all during physical movements.The presented study is not the rst attempt to measure EDA during a sport competition.Bertollo and colleagues reliably measured electrodermal activity of a sports shooter and a darts player during more than a hundred shots (Bertollo et al, 2013).Novelty of the presented ndings are in relation to lateral asymmetry.We demonstrate here that the emotional state induced by a darts competition results in location-speci c arousal.Consequently, EDA lateral asymmetry can be reliably detected on the wrists, despite excessive movement of the throwing hand.
The contact between electrodes and the skin is crucial for EDA measurements; thus, type and placement of electrodes requires careful consideration (Boucsein, 2012).The measurement procedure followed technical principals of Dawson's handbook (Dawson et al,200).EDA was measured on the wrist as they are less prone to the physical activity required by the throws.Based on previous results wrists are adequate for bilateral measurements.One of the main issues is whether the direction of lateral asymmetry is affected by physical movement.
To answer this question, we asked Subject 2 to change throwing hands across sets.Results displayed on Fig. 2 suggest that physical activity did not affect lateral asymmetry.Our results con rm that although physical activity does in uence the EDA signal, lateral asymmetry is not an artefact of the throwing hand movement.Further investigation of reattachment of electrodes (Fig. 1) showed that EDA asymmetry was not affected by these factors.Thus, we con rm our rst hypothesis and conclude that raw skin conductance data from wrist locations with stable attachment of the electrodes are reliable sources of EDA lateral asymmetry measurements during speci c psychological states, such as a darts competition.
We also hypothesized that emotional state induced by the competition will result in EDA lateral asymmetry, since the Multiple Arousal Theory (Picard et al., 2016) implicates that the increased arousal in a competition with "high stakes" should trigger different amounts of eccrine sweat gland activity on the different body parts, and thus, level of EDA will be different on distinct body locations.Underlying this theory Picard and colleagues depicted EDA asymmetry between left and right side of the body throughout daily activities with multiple stressful events.At the same time Bjorhei and colleagues (2019) did not report any signi cant EDA lateral asymmetry in two stress-tasks.We demonstrated here that out of 13 right-handed participants in the current study 12 showed lateral asymmetry during the competition (see Figs. 3,4 and supplementary Figure S1).We believe that the setting is crucial in inducing the assumption about stress and triggering the feeling in participants that the "stakes are high".Thus, real life stress situations can induce feelings that are very different from those set up in a laboratory, where participants might have prior beliefs about experimenters' intentions.On the other hand, lateralized EDA response was clearly demonstrated in a laboratory setting where arousal was induced by direct physiological triggers: electric stimulation (Kryklywy et al., 2022), instead pf psychological triggers.Moreover, the direction of lateral asymmetry of the EDA response was limb-speci c, advocating a side-speci c " ght or ight" response.
Individual differences are apparent in electrodermal activity.Some participants show EDA values as low as a few µSiemens, and some over ten µSiemens.Similarly, the degree of laterality can also vary.
According to our results lateral asymmetry characterizing players are mostly consistent throughout the competition, however, difference between wrist EDA measurements of a player may increase during the competition (see Subject 2 for example in Study 3).In addition, Subject 2 showed a right sided lateral asymmetry not only in Study 3, but also in two other studies executed at another time using other Obimon devices (see Figs. 1 and 2).These results demonstrate that the lateral asymmetry of EDA in a high-stake game is likely to be linked to the emotional state of the participant and is not a consequence of external bias, such as re-attachment of electrodes or physical movement.It is also important to note that Subject 2 was characterized by an increasing EDA level and right-hand EDA dominance when throwing the darts in the competition.On the other hand, this right sided asymmetry was less apparent in the time periods of the competition when he watched his partner play when he played the piano after the competition (see Fig. 1).Thus, we con rm our second hypothesis: we detected lateral asymmetry of electrodermal activity that speci cally characterize the arousal state induced by the competition.
To summarize ndings from our rst three studies we may conclude that while selection of measurement location and secure placement of electrodes is important, EDA lateral asymmetry is typical in a competition and can be measured reliably on the wrists despite hand movements.Re-attachment of electrodes in Study 1 did not change laterality, activity induced by the throwing hand did not have signi cant effect on the EDA signal, and switching throwing hands did not in uence laterality.These results are in line with previous ndings from long-term EDA measurements, where EDA asymmetry did not associate with physical activity (Picard, 2016).Thus, we infer that differences of bilateral skin conductance on the wrists characterize EDA lateral asymmetry reliably during a darts competition.

EDA lateral asymmetry as a biomarker of attributional styles
We assumed that attribution of the performance regarding each throw might be linked to laterality of objective EDA measurement portraying their emotional arousal.We based our assumption on the Multiple Arousal Theory (Picard, 2016) highlighting that while two sides of the body typically provide synchronized measures, when EDA levels are different, the pattern can be informative.
According to our best knowledge this is the rst study exploring the possible link between laterality and optimistic/pessimistic attributional styles de ned on the bases of Seligman's theory (Peterson et al, 1982).We demonstrated that the right or left EDA dominance is associated to the explanation provided by the players about their success or failure.Optimistic or pessimistic attribution style was based on Seligman's model (Gillham et al., 2001), suggesting an optimistic attribution if a good throw performance (higher than estimated) was seen as achievement by oneself, and a bad throw performance (lower than estimated) was due to external factors.On the contrary, a pessimistic attribution style would imply that success is due to external factors, while failures have internal causes.Results presented in Table 2 show that EDA lateral asymmetry is linked to attributional styles.Optimistic attribution was signi cantly more frequent while measuring right sided dominance of EDA (84% and 61% in the initial and in the replication sample).In comparison Pessimistic attitudes were linked to left sided dominance (63% and 75%).We suggest that direction of EDA asymmetry may serve as a biomarker of the mental state of players in the competition, characterizing an optimistic or pessimistic self-evaluation related to their throwperformance.
Since this is a novel result, replication of our ndings is necessary.We found that the right sided EDA dominance was linked to the optimistic attitude, which seems to be in contrast with the classical view the right amygdala is linked to pessimism and the left to optimism (Hecht, 2013).At the same time we must note that electrodermal activity may originate either from both ipsilateral and contralateral pathways (Boucsein, 2012).It is possible that in sport performance situations where signi cant physical movement is present, the majority of EDA signals have contralateral pathways.The other explanation implies that the optimist were involved in the game more than pessimist, and thus, they are experiencing a higher stress level which was shown to induce right sided EDA dominance by previous studies (Picard et al, 2016;Kasos et al, 2018).This assumption is in agreement with the idea of "strategic optimism and defensive pessimism" (Gordon 2008).
To summarize ndings from a one-to-one darts competition (Study3) as well as from a group setup (Study 4) we may conclude that lateral asymmetry of emotional arousal may serve as a as a reliable biomarker of attributional style in a competition.This is the rst study to show a signi cant (p = 0.001)

Limitations and impact
The major limitation of the present study could be the small sample size, and that participants were amateur players.Regarding the determination of attribution style one should consider that only one of the three dimensions of Seligman's questionnaire was applicable.Unfortunately, there was a large luck-factor in the amateur player's throws in the presented study, resulting in a high standard deviations of individual performance.Therefore, interrelations between performance and attributional styles could not be detected here.
Wearable EDA sensors are suitable to indicate the real-time emotional status and have potential implications for an applied setting.Direct feedback on emotional status has a potential bene t and often applied in performance optimization together with other psychophysiological measures (Fronso et al., 2017).These autonomic function assessments include various parameters, involving classical unilateral EDA measure.Based on the presented results, use of bilateral EDA setup instead of classical unilateral EDA could serve as an additional feature detection of the arousal state.Biofeedback techniques allow individuals to receive continuous feedback on their self-regulating skills.This could facilitate better sport performance (Blumenstein & Weinstein, 2011), optimal exercise and injury prevention (Düking et al., 2017).

CONCLUSIONS
Here we present multiple evidence for valid measurement of bilateral of electrodermal activity on the right and the left wrists during a darts competition including excessive physical movement.We found that EDA values on the two sides are characteristically different, and that this lateral electrodermal asymmetry re ects emotions that are closely linked to how players attribute their own successes and setbacks.We underlie implications of the Multiple Arousal Theory and suggest that Lateral asymmetry of emotional arousal is a novel psychophysiological biomarker of attribution style.
Re These periods are followed by waiting times for Subject 2, indicated by "partner plays" labels.After the darts game, Subject 2 played the piano.The "re-attach" labels signal the two short time periods (28 and 35 seconds), when devices and electrodes were taken off from both wrists, and then devices were reattached using new electrodes.

3 Hypotheses 1 .
The unit of statistical analysis was the throw interval.Two main variables characterizing each throw were used in the analyses: left or right dominance of EDA and the optimist or pessimist attribution type.Chi square tests were performed separately for initial study (Study 3) and for the replication (Study 4) Differences in bilateral skin conductance can be measured reliably on the wrists during darts competition.

Skin conductance values of Subject 2 in
Study 2 are displayed: right hand throws in set 3 and left hand throws in set 4. All sets involved 10 throws.The red line represents EDA measurements from the right wrist, and the blue line represents left wrist skin conductance in µS.Small vertical gray lines with numbers represent the moment of throws.Long vertical gray lines show the ± 4 seconds time interval of each throw.
-attachment of electrodes between sets during darts competition (Study 1).Skin conductance values of Subject 2 are displayed for the three sets.The red line represents right wrist skin conductance in μS, and the blue line represents left wrist EDA during the 40-minute competition.Set 1, 2 and 3 labels highlight the time frame of a couple of minutes, when Subject 2 was throwing the darts.

Table 1
Main characteristics of the Studies 1-4 and participants.

Table 2
Lateral electrodermal asymmetry and the attribution style (Kasos et al., 2020)s measured EDA from the wrist during sleep(Sano et al., 2014), and our research group measured bilateral electrodermal activity from ve different sites of the body: ngers, feet, calves, shoulders, and wrists(Kasos et al., 2020).Most EDA studies require subjects to keep their hands still while EDA is being measured, since physical activity alters the EDA signal (Posada-Quintero, Reljin, et al., 2018).On the other hand, ecological validity of EDA measurements requires wearable devices and the opportunity for measuring normal daily-life activities.We acknowledge that measuring valid EDA is a challenge during physical activity due to movement artifacts, thus Study 1 and Study 2 investigated several aspects of measurement reliability.
association of attributional style and right or left sided EDA dominance.Results clearly indicate that bilateral assessment of arousal is relevant.Our results indicate meaningful psychophysiological correlates of EDA measurements from distinct body locations -as proposed by the Multiple Arousal Theory (Picard et al., 2016).