Unilateral Left-Hand Contractions Produce Widespread Depression of Cortical Activity after Their Execution

Haptic coordination: Squeezing a vibrating stress ball decreases anxiety and arousal

We evaluated the effect of haptic coordination on anxiety and arousal. Participants looked at a stressful or calming image and then repeatedly squeezed a vibrating stress ball for 20 s. Using a pre-post paradigm with a control group, we showed that squeezing the vibrating ball reduced anxiety and arousal, as assessed by the State-Trait Anxiety Inventory and electrodermal activity, respectively. The stability of haptic coordination was manipulated by varying the detuning between the spontaneous squeezing frequency and the intrinsic frequency of ball vibration. Coordination stability affected arousal and stress affected stability. The data were discussed in the light of Kahneman's attentional resource-sharing model.

The Impact of Hemispheric Activity Priming on Choking Under Pressure in Badminton Tasks: A Study of Three Fundamental Skills

Choking under pressure occurs when an individual experiences a decrease in performance despite their efforts to perform well. The self-focus approach suggests that pressure increases conscious attention on the performance process, disrupting the automatic or overlearned nature of execution. Hemispheric asymmetries in the brain and skilled performance indicate that left-hemispheric activity decreases, while right-hemispheric activity enhances. Previous studies have attempted to prevent choking by inhibiting the left hemisphere or enhancing the right hemisphere's activity. This study examined whether increased hemispheric activity priming can extenuate motor skill failure under pressure in badminton tasks. The study involved 32 right-handed college students who completed five conditions in pressure-free blocks versus choking under-pressure blocks with priming intervention. Results showed a significant improvement in motor learning from pre- to post-tests, but participants still choked under pressure during skill execution. Furthermore, the priming strategy (hand squeezing) did not alleviate the pressure to benefit performance. The study provides evidence of performance decrements under pressure conditions, and the priming strategy did not alleviate choking.

Skilled Performers Show Right Parietal Lateralization during Anticipation of Volleyball Attacks

Global and local biological motion processing are likely influenced by an observer's perceptual experience. Skilled athletes anticipating an opponent's movements use globally distributed motion information, while less skilled athletes focus on single kinematic cues. Published reports have demonstrated that attention can be primed globally or locally before perceptual tasks; such an intervention could highlight motion processing mechanisms used by skilled and less skilled observers. In this study, we examined skill differences in biological motion processing using attentional priming. Skilled (N = 16) and less skilled (N = 16) players anticipated temporally occluded videos of volleyball attacks after being primed using a Navon matching task while parietal EEG was measured. Skilled players were more accurate than less skilled players across priming conditions. Global priming improved performance in both skill groups. Skilled players showed significantly reduced alpha and beta power in the right compared to left parietal region, but brain activity was not affected by the priming interventions. Our findings highlight the importance of right parietal dominance for skilled performers, which may be functional for inhibiting left hemispheric local processing or enhancing visual spatial attention for dynamic visual scenes. Further work is needed to systematically determine the function of this pattern of brain activity during skilled anticipation.

Using a haptic dynamic clamp to reduce arousal: preference, arousal, and coordination stability are related

We have developed a haptic dynamic clamp dedicated to the regulation of arousal. It takes the form of a vibrating stress ball to be squeezed, called Viball, controlled by Righetti's nonlinear adaptive Hopf oscillator. Participants squeezed an adaptive Viball which adapts its frequency of vibration to the current frequency of human squeezing. The adaptive Viball was compared to three non-adaptive Viballs, parametrized to vibrate at a lower, equal, or higher frequency than the participants' preferred frequency. While squeezing the ball, participants looked at stressful or calming pictures and their electrodermal activity was recorded. Using the preference paradigm, we show that participants preferred to interact with the adaptive Viball rather than with the most slowly vibrating ball that most strongly reduced arousal. The stability of the human-ball coordination was the highest with the adaptive Viball. There was also a positive correlation between the stability of coordination and arousal. The data are discussed in light of the energy-based interpretation of coordination dynamics.

Individual vs. Team Sport Failure-Similarities, Differences, and Current Developments

The construct of "choking under pressure" is concerned with the phenomenon of unexpected, sudden, and significant declines in individual athletes' performances in important situations and has received empirical attention in the field of sport psychology. Although a number of theories about the reasons for the occurrence of choking under pressure exist and several intervention approaches have been developed, underlying mechanisms of choking are still under debate and the effectiveness of existing interventions remains contested. These sudden performance declines also occur in team sport. "Collective sport team collapse," which describes the situation when an entire sport team underperforms significantly within an important competitive situation, has received less empirical attention, in comparison to individual choking research. While there are a few studies that have investigated causes of collective team collapse, understandably, there has been limited empirical investigation of preventative and intervention strategies. Although the two constructs appear to share several similar characteristics and mechanisms, research has not yet examined the conceptual, theoretical, empirical, and practical links between choking under pressure and collective sport team collapse. In this review article, we seek to examine these similarities and differences and identify new ways of thinking about future interventions. Furthermore, current empirical understandings in the field of choking under pressure and collective sport team collapse are presented and the most effective intervention approaches for both constructs are introduced. On the basis of this examination, we modestly make some initial recommendations for sport psychological practitioners and future research.

Effects of unilateral dynamic handgrip on reaction time and error rate

Quick and accurate reactions to environmental stimuli are often required. Researchers have investigated ways to improve these reactions, which are critical components of perceptual-motor abilities. To optimize individual performance, different techniques, such as embodied interventions and brain stimulation, have been examined. The evidence from EEG studies shows that upper limb muscle contractions lead to changes in brain oscillations associated with changes in mental states and behavioral outcomes. Much research has been conducted on whether muscle contractions of a particular hand have a greater effect on a perceptual-motor ability, as a trigger to facilitate cortical processes (a mediator) for skilled motor performance. While previous studies have shown that left- (vs. right-) hand contractions can lead to greater alpha activation, we hypothesized that left dynamic handgrips have different impacts on motor performance, reflected by simple RT (SRT) and choice RT (CRT). We recruited 64 right-handers, for a within/between-subjects experiment consisting of performance measurements in SRT and CRT tasks after the intervention (either right or left dynamic handgrip approximately twice a second for 30 s for each hand) or assignment to paired passive control groups. We did not find left-hand contractions improve response accuracy in neither SRT nor CRT tasks. Further, left-hand contractions did not affect RTs. The findings indicate that the effects of dynamic handgrips are smaller on behavioral outcomes such as RTs than what can be inferred from published studies. More research is needed to establish the effect of dynamic handgrips on optimizing performance.

Preventing a loss of accuracy of the tennis serve under pressure

Dynamically squeezing the left hand (left hand dynamic handgrip) has been shown to be effective in preventing choking under pressure in right-handers in a variety of sports. The current study assessed the effectiveness of the left hand dynamic handgrip in preventing a loss of accuracy of tennis serves in competitive situations. Twenty right-handed highly skilled junior athletes performed eight tennis serves at a target without pressure (pre-test), followed by eight serves under pressure (post-test). Ten of the participants conducted the left hand dynamic handgrip prior to the post-test, while the other ten performed an equivalent handgrip with their right hand. The serving accuracy of the group performing the handgrip with their right hand decreased significantly from pre- to post-test, while the accuracy of the left hand dynamic handgrip group remained stable. The results indicate the left hand dynamic handgrip to be effective in preventing reduced accuracy of the tennis serve in competition situations as a form of choking under pressure. This technique could easily be integrated into tennis players' serving routines and promote stable match performance in competitions.

Motives and Laterality: Exploring the Links

Objectives

We explored associations between the needs for power, achievement, and affiliation and functional cerebral asymmetries (FCAs), guided by three established hypotheses about the nature of these associations.

Methods

One-hundred-and-seven participants completed picture-story measures of dispositional motives and activity inhibition (AI), a frequent moderator of motive-behavior associations, tasks measuring FCAs (line bisection, chimeric emotional face judgments, turning bias, perceptual and response asymmetries on the Poffenberger task), self-reported laterality preferences (handedness, footedness, ear and eye preference), and interhemispheric interaction (crossed-uncrossed difference). They also completed an experiment manipulating hand contractions (left, right, both, neither) while they worked on a second picture-story motive measure.

Results

Dispositional power motivation was associated with stronger rightward asymmetry and less interhemispheric transfer in high-AI and stronger leftward asymmetry and more interhemispheric transfer in low-AI individuals. For the affiliation motive, findings were fewer and in the opposite direction of those for the power motive. These findings emerged for men, but not for women. Left- or right-hand contractions led to increases in power and achievement motivation, but not affiliation motivation. Only left-hand contractions led to decreased AI.

Conclusions

We discuss these findings in the context of sex-dimorphic organizing and activating effects of steroids on motives and laterality.

Exploring approach motivation: Correlating self-report, frontal asymmetry, and performance in the Effort Expenditure for Rewards Task

Frontal EEG asymmetry has been investigated as a physiological metric of approach motivation, with higher left frontal activity (LFA) suggested to reflect approach motivation. However, correlations between LFA and traditional metrics of approach motivation (e.g., scores from the behavioral inhibition system/behavioral approach system [BIS/BAS] survey) are inconsistent. It is also not clear how LFA correlates to approach motivation on an observable, behavioral level. Here, we tested correlations between BIS/BAS scores, LFA, and performance in the Effort Expenditure for Rewards Task (EEfRT). In our sample (n = 49), BIS/BAS results did not correlate to LFA values (resting or task states), and were also unrelated to EEfRT performance variables. We found evidence of significant and distinct correlations between LFA and EEfRT performance. Resting-state LFA positively correlated to effort expenditure on lower utility trials, where reward size and/or probability were suboptimal. Task-onset LFA captured in the first 5 min of the task was related to overall behavioral performance in the EEfRT. High task-onset LFA correlated to high trial completion rates, high-effort trial selection percentages, and overall monetary earnings. One interpretation of these initial findings is that resting-state LFA reflects approach tendencies to expend effort, but that this extends to suboptimal situations, whereas task-state LFA better reflects effortful approach toward high-utility goals. Given the relatively small sample size and the risk of Type I/II errors, we present the study as exploratory and the results as preliminary. However, the findings highlight interesting initial links between LFA and EEfRT performance. The need for larger replication studies is discussed.

Effects of the unilateral dynamic handgrip on resting cortical activity levels: A replication and extension

Previous studies have linked unilateral hand contractions to subsequent changes in hemispheric asymmetric activity, as reflected in the electroencephalographic alpha (8-12 Hz) range in each hemisphere. However, debate continues regarding the state of asymmetry induced by unilateral contractions. We have previously found a bilateral enhancement of alpha amplitude that occurs after contractions, reflecting cortical downregulation instead of changes in asymmetric activity. To corroborate our observations, we examined the effects of 45 s of unilateral dynamic handgrip contractions on subsequent resting alpha activity. Twenty-two right-handed participants were recruited (M = 25 years, 17 female). The study used a within-subjects design consisting of a pre- and post-test (2 min resting; eyes open) for the intervention (dynamic handgrip; at a self-determined pace of approximately twice a second for 45 s for each hand). Following the handgrip task, an increase in alpha amplitude above the baseline was observed over the entire cortex, which was greater after left-hand squeezing. This observation confirms our previous findings and we have extended them by adding more electrodes to gain further insights into the handgrip exercise as an external brain stimulator. Moreover, we grouped electrodes according to scalp regions to facilitate the visualization of the effects on the frequency spectrum. Our findings can be used to develop targeted interventions aimed at modifying behavioral outcomes affected by alpha activity.

Investigating cumulative effects of pre-performance routine interventions in beach volleyball serving

Pre-performance routines (PPRs) can be used in certain sports to minimize the effects of choking under pressure. This study aimed to investigate the cumulative effectiveness of PPR interventions on the accuracy of beach volleyball serves. Fifty-four beach volleyball players were randomly assigned to one of three PPR intervention groups or a control group. Participants performed 10 serves at a target on the opposite side of the beach volleyball court (pretest), were educated on a PPR intervention, and then completed 10 serves at the target under pressure that was induced through videotaping and ego-relevant instructions (posttest). The results indicated no difference in post-test serving accuracy among the intervention groups and the wait-list control group and no difference in effectiveness between cumulative and isolated PPR use. A possible explanation may be the inefficiency of the pressure manipulation. However, the null results related to isolated and cumulative PPR use under general (i.e., no pressure) conditions are still an important research finding. Future research should investigate the effectiveness of cumulative and other PPRs in other sports in general and under pressure.

Using the landmark task to test the underlying assumptions of unilateral contraction research

The unilateral contractions procedure (i.e., squeezing a ball with one hand) supposedly enhances a wide variety of cognitive functions, from episodic recall to choking under pressure. The practicality and affordability of this procedure makes it highly appealing. But does it work? We addressed this question by testing whether intermittent and sustained unilateral contractions shifted a well-supported hemispheric asymmetry: visuospatial attention. Based on prior research, contracting the left (or right) hand should lead baseline scores on the landmark task-a visuospatial attention measure-to deviate further left (or right). We meta-analysed the results of our six experiments and showed that the unilateral contractions procedure, particularly with intermittent contractions, does not reliably shift landmark task scores measured during (Experiments 4-6) or after (Experiments 1-3 & 6) performing unilateral contractions. Although we question if and how unilateral contractions activate the contralateral hemisphere, Experiment 6 provided some support for the utility of sustained contractions.

An Investigation Into Handedness and Choking Under Pressure in Sport

When athletes fail to perform at an expected level during an important moment, it is implied the athletes have experienced "choking" (sudden decline in performance) under pressure.". Researchers have reported that persistent left-hemispheric activation patterns occur when an athlete experiences considerable performance deteriorations under pressure. Researchers have also observed differences in brain activation patterns between left- and right-handed people on a variety of physical and cognitive tests, with the left-hemispheric activation more pronounced in right-handed participants.

PURPOSE

The purpose of this study was to investigate whether athletes' handedness may be linked to choking susceptibility (i.e., likelihood to experience performance decline under pressure).

METHOD

Twenty right-handed and 13 left-handed experienced Australian football players completed 15 shot attempts, in both a low-pressure and a high-pressure condition. Both groups displayed equal state anxiety increases due to the pressure manipulation, indicating similar increases in anxiety in both handedness groups.

RESULTS

Differences were indicated in performance between the left- and right-handed groups during the high-pressure condition, with the left-handed group maintaining, and the right-handed participants declining, performance.

CONCLUSION

Future electroencephalogram (EEG) research investigating this link may clarify the effect between handedness and choking.

Effects of Unilateral Hand Contraction on The Persistence of Hemispheric Asymmetry of Cortical Activity

Abstract. Athletes who squeezed a ball with their left hand immediately prior to execution of sports activities did not show performance deterioration under severe pressure ( Beckmann, Gröpel, & Ehrlenspiel, 2013 ). This result has been explained by priming of the dominant right hemisphere. However, it remains unclear what variables have the greatest effect on asymmetrical brain activity (e.g., duration and strength of ball squeezing). We hypothesized that squeezing a ball harder for a longer period might lead to stronger asymmetrical activity because motor-related areas would have increased activation due to the more forceful movement. We used electroencephalograms (EEGs) to investigate the hemispheric asymmetry of brain activity produced by squeezing a ball with a unilateral hand. EEGs were assessed during a baseline period as well as in eight experimental conditions wherein the strength and duration of the ball squeeze were manipulated. Our results showed that right-hemispheric-dominant brain activation was maximized when participants squeezed with their left hand a ball that had an internal pressure of 100 hPa for 90 s or 20 hPa for 30 s. Moreover, squeezing the ball with 100 hPa internal pressure for 90 s created a prominent interhemispheric asymmetry of cortical activity. We suspect that squeezing a ball strongly for a long period might be helpful in dealing with “choking” under pressure by producing greater right-hemispheric activation. This result could help improve simple methods for competitive athletes to reduce the likelihood of exhibiting choking behavior that could be practiced with minimal effort, even during short breaks during a game.

Choking under pressure: theoretical models and interventions

In sport, choking under pressure is a major concern for athletes, coaches and sport psychologists because athletes fail to meet self-imposed performance expectations in critical situations (when it counts the most), which is devastating and embarrassing. Researchers have debated choking under pressure definitions, identified personality characteristics that exacerbate choking outcomes, and examined models to determine mechanisms for choking. Based on these investigations, several interventions to prevent choking have been developed and tested. In this review, we specifically discuss current self-presentation and attention models and theory-driven interventions that help to alleviate choking in order to facilitate the understanding of this complex phenomenon by athletes, sport psychologists and researchers.