Bernd Strauss

Social facilitation in motor tasks: a review of research and theory.

Abstract Background and purpose . To overview research and theories on the impact of social facilitation for persons performing motor tasks. Methods . A narrative review is adopted. The origins of the research tradition are presented and the different theoretical explanations are reviewed. Results and conclusions . It is noted that these explanations claim validity for both the cognitive and motor domains. Results of research are reported on the impact of the presence of others while working on different kinds of motor tasks such as coordination tasks, power and stamina tasks, and a mixture of these. These empirical findings are often in contradiction to the presented theoretical models. The paper discusses whether results of different kinds of motor tasks need different theoretical explanations. It is concluded that if any effects of the mere presence of others are to be found at all, they tend to be weak.

The effect of attentional focus on running economy

Abstract In research on motor control, the detrimental effect of an internal focus of attention on movement execution of well-learned motor skills is a frequently replicated finding. This experimental study was designed to determine whether this effect is observed with physiological variables during endurance exercise. We examined whether the focus of attention can influence running economy (oxygen consumption at a set running speed). Trained runners had to focus their attention on three different aspects while running on a treadmill. For three consecutive 10-min periods, runners concentrated on the running movement, on their breathing, and on their surroundings. Results showed an increased running economy in the external focus condition. In line with research on motor control, endurance sport also shows that an external focus of attention is better than an internal focus in terms of the physiological performance measure of oxygen consumption.

Visual perception in fencing: Do the eye movements of fencers represent their information pickup?

The present study examined whether results of athletes’ eye movements while they observe fencing attacks reflect their actual information pickup by comparing these results with others gained with temporal and spatial occlusion and cuing techniques. Fifteen top-ranking expert fencers, 15 advanced fencers, and 32 sport students predicted the target region of 405 fencing attacks on a computer monitor. Results of eye movement recordings showed a stronger foveal fixation on the opponent’s trunk and weapon in the two fencer groups. Top-ranking expert fencers fixated particularly on the upper trunk. This matched their performance decrements in the spatial occlusion condition. However, when the upper trunk was occluded, participants also shifted eye movements to neighboring body regions. Adding cues to the video material had no positive effects on prediction performance. We conclude that gaze behavior does not necessarily represent information pickup, but that studies applying the spatial occlusion paradigm should also register eye movements to avoid underestimating the information contributed by occluded regions.

Left-Handedness in Professional and Amateur Tennis

Negative frequency-dependent effects rather than innate predispositions may provide left-handers with an advantage in one-on-one fighting situations. Support mainly comes from cross-sectional studies which found significantly enhanced left-hander frequencies among elite athletes exclusively in interactive sports such as baseball, cricket, fencing and tennis. Since professional athletes’ training regimes continuously improve, however, an important unsolved question is whether the left-handers’ advantage in individual sports like tennis persists over time. To this end, we longitudinally tracked left-hander frequencies in year-end world rankings (men: 1973–2011, ladies: 1975–2011) and at Grand Slam tournaments (1968–2011) in male and female tennis professionals. Here we show that the positive impact of left-handed performance on high achievement in elite tennis was moderate and decreased in male professionals over time and was almost absent in female professionals. For both sexes, left-hander frequencies among year-end top 10 players linearly decreased over the period considered. Moreover, left-handedness was, however, no longer seems associated with higher probability of attaining high year-end world ranking position in male professionals. In contrast, cross-sectional data on left-hander frequencies in male and female amateur players suggest that a left-handers’ advantage may still occur on lower performance levels. Collectively, our data is in accordance with the frequency-dependent hypothesis since reduced experience with left-handers in tennis is likely to be compensated by players’ professionalism.

Cognitive Fatigue Effects on Physical Performance During Running

This study investigated the effect of cognitive fatigue on physical performance in a paced running task. Experienced runners (n = 20) performed two 3,000-m runs on an indoor track, once after cognitive fatigue, and once under nonfatigued conditions. Completion times were significantly slower in the cognitive fatigue condition (M = 12:11,88 min, SD = 0:54,26), compared with the control condition (M = 11:58,56 min, SD = 0:48,39), F(1, 19) = 8.58, p = .009, eta2p = .31. There were no differences in heart rate, t(17) = 0.13, p > .05, blood lactate levels, t(19) = 1.19, p > .05, or ratings of perceived exertion F(1, 19) = .001, p > .05. While previous research has examined the impact of cognitive tasks on physical tasks, this is the first study to examine a self-paced physical task, showing that cognitive activity indeed contributes significantly to overall performance. Specifically, cognitive fatigue increased the perception of exertion, leading to lesser performance on the running task.

Visual span and change detection in soccer: An expertise study

There is evidence to suggest that sports experts are able to extract more perceptual information from a single fixation than novices when exposed to meaningful tasks that are specific to their field of expertise. In particular, Reingold et al. (2001) showed that chess experts use a larger visual span including fewer fixations when compared to their less skilled counterparts. The aim of the present study was to examine whether also in a more complex environment, namely soccer, skilled players use a larger visual span and fewer fixations than less skilled players when attempting to recognise players’ positions. To this end, we combined the gaze-contingent window technique with the change detection paradigm. Results seem to suggest that skilled soccer players do not use a larger visual span than less skilled players. However, skilled soccer players showed significantly fewer fixations of longer duration than their less skilled counterparts, supporting the notion that experts may extract more information from a single glance.

An internal focus of attention is not always as bad as its reputation: how specific aspects of internally focused attention do not hinder running efficiency.

The aim of this study was to examine differentiated effects of internally focused attention in endurance sports. Thirty-two active runners ran 24 min on a treadmill at a fixed speed of moderate intensity. For each 6-min block, participants had to direct their attention on different internal aspects (movement execution, breathing, or feeling of the body) or received no instructions. Oxygen consumption (VO2) was measured continuously to determine running economy. Results revealed that the different internal focus instructions had differentiated effects on VO2: A focus on breathing as well as a focus on the running movement led to higher VO2 than a focus on feeling of the body which showed similar VO2 as the control condition. We conclude that an internal focus of attention is solely detrimental to performance when directed to highly automated processes (e.g., breathing or movement). However, an internal focus on how the body feels during exercise does not disrupt movement efficiency.

The Serve in Professional Men’s Tennis: Effects of Players’ Handedness

The serve is one of the most important strokes in tennis and has often been the subject of sport scientific investigation. Left-handed players are said to have an advantage in tennis, especially when serving against a right-handed player to the advantage court. We investigated the serving strategies of male left- and righthanded professional tennis players whose serves (N= 4744) were recorded by the automated ball tracking Hawk-Eye system at international tournaments. Right- and left-handed serves differed significantly regarding the ball distribution in the opponent’s service box at both first and second serves as well as regarding the angle of lateral ball flight. As a consequence, players have to take into account different probabilities regarding the direction of serve when awaiting right- vs. lefthanded serves. At the same time, they also need to adjust their return stroke due to the different spin imposed on balls served right- vs. left-handed. Furthermore, analyses also revealed that the left-handers’ serve is not simply mirrored to that of right-handers but still significantly different. In light of the reduced familiarity with the left-hander’s style of play, the findings suggest that for the serve in tennis tactical and technical aspects may promote the left-handers’ advantage.

Transfer of motor and perceptual skills from basketball to darts

The quiet eye is a perceptual skill associated with expertise and superior performance; however, little is known about the transfer of quiet eye across domains. We attempted to replicate previous skill-based differences in quiet eye and investigated whether transfer of motor and perceptual skills occurs between similar tasks. Throwing accuracy and quiet eye duration for skilled and less-skilled basketball players were examined in basketball free throw shooting and the transfer task of dart throwing. Skilled basketball players showed significantly higher throwing accuracy and longer quiet eye duration in the basketball free throw task compared to their less-skilled counterparts. Further, skilled basketball players showed positive transfer from basketball to dart throwing in accuracy but not in quiet eye duration. Our results raise interesting questions regarding the measurement of transfer between skills.

Home advantage in soccer – A matter of expectations, goal setting and tactical decisions of coaches?

Abstract In soccer, home teams win about 67% of decided games. The causes for this home advantage are still unresolved. There is a shortage of research on the psychological states of actors involved. In this study, we examined soccer coaches’ expectations, goal setting and tactical decisions in relation to game location. Soccer coaches (N = 297) with different expertise levels participated in an experimental, online management game and were randomly assigned to one of two groups, “home game (HG)” or “away game.” Participants received information on the game for which they were asked to make decisions in multiple points. The only differing information between groups was game location. Regardless of expertise, HG coaches had higher expectations to win, set more challenging goals and decided for more offensive and courageous playing tactics. Possible consequences of these findings concerning home advantage in soccer are discussed.