Tino Stöckel

Brain lateralisation and motor learning: selective effects of dominant and non-dominant hand practice on the early acquisition of throwing skills.

Findings from neurosciences indicate that the two brain hemispheres are specialised for the processing of distinct movement features. How this knowledge can be useful in motor learning remains unclear. Two experiments were conducted to investigate the influence of initial practice with the dominant vs non-dominant hand on the acquisition of novel throwing skills. Within a transfer design two groups practised a novel motor task with the same amount of practice on each hand, but in opposite hand-order. In Experiment 1, participants acquired the position throw in basketball, which places high demands on throwing accuracy. Participants practising this task with their non-dominant hand first, before changing to the dominant hand, showed better skill acquisition than participants practising in opposite order. In Experiment 2 participants learned the overarm throw in team handball, which requires great throwing strength. Participants initially practising with their dominant hand benefited more from practice than participants beginning with their non-dominant hand. These results indicate that spatial accuracy tasks are learned better after initial practice with the non-dominant hand, whereas initial practice with the dominant hand is more efficient for maximum force production tasks. The effects are discussed in terms of brain lateralisation and bilateral practice schedules.

Acquisition of a Complex Basketball-Dribbling Task in School Children as a Function of Bilateral Practice Order.

Abstract The purpose of this study was to investigate order-of-practice effects for the acquisition of a complex basketball skill in a bilateral transfer paradigm. The task required participants to dribble as fast as possible in slalom-like movements across six javelins and return to the initial position. Fifty-two right-handed school children (M age = 11.7 years) practiced this skill in eight sessions over 4 weeks under one of two training schedules: (a) with the dominant hand, before changing to their nondominant hand (D-ND group), or (b) with the nondominant hand, before changing to the dominant hand (ND-D group). All tests were conducted with the right hand or the left hand only, and a transfer test was given with both hands alternating. The results of a retention test yielded significantly larger learning gains for the ND-D group as compared to the D-ND group. It is interesting that this performance advantage was independent of the respective hand tested. The same pattern of result was found in the transfer test, with significantly shorter movement times for the ND-D group with both hands alternating. Such order-of-practice effects for the acquisition of complex skills can be explained with hemispheric brain asymmetries for the processing of specific task requirements.

Plasticity of human handedness: Decreased one-hand bias and inter-manual performance asymmetry in expert basketball players

Abstract Athletes frequently have to adapt their skills to fast changes of play, often requiring the flexible execution of a particular movement skill with either hand. To assess the influence of sport-specific expertise and extensive sport training on human laterality, a video analysis of regular basketball games was performed for professional, semi-professional, and amateur players to investigate how non-dominant hand use and proficiency change with increasing expertise. Our results showed that the right-hand (i.e. dominant hand) bias in basketball players is reduced with increasing expertise (i.e. competitive level). Accordingly, we found that professional players use their non-dominant hand more often and with greater success than semi-professional and amateur players. This was true for most of the basketball-specific skills. Based on these results, we assume that increasing amounts of bilateral practice can lead to a shift in task-specific manual preference towards a higher use of both hands in competition, as well as to a higher proficiency for non-dominant hand actions in particular. From an applied perspective, the more frequent use and higher proficiency of the non-dominant hand in professional basketball players, compared with amateurs, suggests that the context-specific and skilled use of the non-dominant hand is crucial for successful play at higher competitive levels in the sport of basketball.

Effects of multiple planning constraints on the development of grasp posture planning in 6- to 10-year-old children.

This experiment examined how multiple planning constraints affect grasp posture planning in 6- to 10-year-old children (n = 16 in each group) by manipulating the intended object end-orientation (left end-down, right end-down) and initial precision demands (standard, initial precision) of a bar transport task. Results indicated that grasp posture planning was strongly influenced by multiple planning constraints. During the standard condition the sensitivity toward comfortable final hand postures (end-state comfort) was similar for all age groups in right end-down trials, and corresponded to values reported in adult populations. In contrast, there was an age-related increase in end-state comfort compliance during left end-down trials. During the initial precision condition end-state comfort was similar across all groups for left end-down trials. However, end-state comfort compliance was significantly lower for the 6-year-old children than in all other age groups for right end-down trials. In sum, the ability of children to plan their goal-related movements is influenced by the presence of task-related constraints that increase the overall cognitive demands of the task. The demands associated with selecting the appropriate grasp posture during the most cognitive demanding condition required more cognitive resources than 6- to 10-year-old children possess. Removing the conflict between the goal-directed and habitual systems reduces some of these costs, with data indicating that the ability to integrate multiple planning constraints first emerges at 7 years of age, and improves over the developmental spectrum.

The mental representation of the human gait in young and older adults

The link between mental representation (MREP) structures and motor performance has been evidenced for a great variety of movement skills, but not for the human gait. Therefore the present study sought to investigate the cognitive memory structures underlying the human gait in young and older adults. In a first experiment, gait parameters at comfortable gait speed (OptoGait) were compared with gait-specific MREPs (structural dimensional analysis of MREP; SDA-M) in 36 young adults. Participants were divided into a slow- and fast-walking group. The proven relationship between gait speed and executive functions such as working memory led to the hypothesis that gait pattern and MREP differ between slow- and fast-walking adults. In a second experiment, gait performance and MREPs were compared between 24 young (27.9 years) and 24 elderly (60.1 years) participants. As age-related declines in gait performance occur from the seventh decade of life onward, we hypothesized that gait parameters would not be affected until the age of 60 years accompanied by unchanged MREP. Data of experiment one revealed that gait parameters and MREPs differed significantly between slow and fast walkers. Notably, eleven previously incurred musculoskeletal injuries were documented for the slow walkers but only two injuries and one disorder for fast walkers. Experiment two revealed no age-related differences in gait parameters or MREPs between healthy young and older adults. In conclusion, the differences in gait parameters associated with lower comfortable gait speeds are reflected by differences in MREPs, whereby SDA-M data indicate that the single limb support phase may serve as a critical functional period. These differences probably resulted from previously incurred musculoskeletal injuries. Our data further indicate that the human gait and its MREP are stable until the age of 60. SDA-M may be considered as a valuable clinical tool for diagnosis of gait abnormalities and monitoring of therapeutic effectiveness.

Anticipatory Motor Planning in Older Adults

Objectives The end-state comfort (ESC) effect represents an efficiency constraint in anticipatory motor planning. Although young adults usually avoid uncomfortable postures at the end of goal-directed movements, newer studies revealed that childrens sensitivity for ESC is not fully in place before the age of 10 years. In this matter, it is surprising that nothing is known about the development of the ESC effect at older ages. Therefore, the aim of the present study was to examine the development of anticipatory motor planning in older adults. Method In 2 experiments, a total of 119 older adults (from 60 to 80 years old) performed in an unimanual (Experiment 1) and a bimanual version (Experiment 2) of the bar-transport-task. Results Across both experiments, the propensity of the ESC effect was significantly lower in the old-old (71-80 years old) as compared with the young-old (60-70 years old) participants. Discussion Although the performance of the young-old participants in the unimanual and bimanual task was comparable to what has been reported for young adults, the performance of the old-old participants was rather similar to the behavior of children younger than 10 years. Thus, for the first time, evidence is provided for the decrease of the ESC effect in older adults.

Age-Specific Effects of Mirror-Muscle Activity on Cross-Limb Adaptations Under Mirror and Non-Mirror Visual Feedback Conditions

Cross-limb transfer (CLT) describes the observation of bilateral performance gains due to unilateral motor practice. Previous research has suggested that CLT may be reduced, or absent, in older adults, possibly due to age-related structural and functional brain changes. Based on research showing increases in CLT due to the provision of mirror visual feedback (MVF) during task execution in young adults, our study aimed to investigate whether MVF can facilitate CLT in older adults, who are known to be more reliant on visual feedback for accurate motor performance. Participants (N = 53) engaged in a short-term training regime (300 movements) involving a ballistic finger task using their dominant hand, while being provided with either visual feedback of their active limb, or a mirror reflection of their active limb (superimposed over the quiescent limb). Performance in both limbs was examined before, during and following the unilateral training. Furthermore, we measured corticospinal excitability (using TMS) at these time points, and assessed muscle activity bilaterally during the task via EMG; these parameters were used to investigate the mechanisms mediating and predicting CLT. Training resulted in significant bilateral performance gains that did not differ as a result of age or visual feedback (both p > 0.1). Training also elicited bilateral increases in corticospinal excitability (p < 0.05). For younger adults, CLT was significantly predicted by performance gains in the trained hand (β = 0.47), whereas for older adults it was significantly predicted by mirror activity in the untrained hand during training (β = 0.60). The present study suggests that older adults are capable of exhibiting CLT to a similar degree to younger adults. The prominent role of mirror activity in the untrained hand for CLT in older adults indicates that bilateral cortical activity during unilateral motor tasks is a compensatory mechanism. In this particular task, MVF did not facilitate the extent of CLT.

Hand preference patterns in expert basketball players: interrelations between basketball-specific and everyday life behavior.

In the present study we examined the interrelation of everyday life handedness and hand preference in basketball, as an area of expertise that requires individuals being proficient with both their non-dominant and dominant hand. A secondary aim was to elucidate the link between basketball-specific practice, hand preference in basketball and everyday life handedness. Therefore, 176 expert basketball players self-reported their hand preference for activities of daily living and for basketball-specific behavior as well as details about their basketball-specific history via questionnaire. We found that compared to the general population the one-hand bias was significantly reduced for both everyday life and basketball-specific hand preference (i.e., a higher prevalence of mixed-handed individuals), and that both concepts were significantly related. Moreover, only preference scores for lay-up and dribbling skills were significantly related to measures of basketball-specific practice. Consequently, training-induced modulations of lateral preference seem to be very specific to only a few basketball-specific skills, and do not generalize to other skills within the domain of basketball nor do they extend into everyday life handedness. The results are discussed in terms of their relevance regarding theories of handedness and their practical implications for the sport of basketball.

Reihenfolgeeffekte für das Erlernen komplexer sportmotorischer Fertigkeiten auf beiden Körperseiten Eine Basketballuntersuchung bei Schulkindern

Zusammenfassung. Die vorliegende Arbeit untersuchte Reihenfolgeeffekte fur das Erlernen einer komplexen Basketballwurftechnik innerhalb eines Transferparadigmas. Dafur trainierten 16 Schulkinder (Durchnittsalter M = 12.1 Jahre) in 8 Ubungseinheiten uber 4 Wochen hinweg in einem von zwei Trainingsablaufen: (1) zuerst mit der rechten Hand und danach mit der linken Hand (Re-Li Gruppe), oder (2) zuerst mit der linken Hand und danach mit der rechten Hand (Li-Re Gruppe). Die primare Aufgabe bestand darin, einen Basketball in 30 Sekunden so oft und genau wie moglich in ein Zielfeld an der Wand zu werfen. Nach einem Pretest und der Trainingsphase, uberpruften wir den Lernzuwachs anhand der erzielten Trefferpunkte in einem Post- und Retentionstest, sowie in einem Aufgaben-Transfertest beim Werfen auf den Basketballkorb. Alle Tests wurden mit der rechten Hand, der linken Hand und beiden Handen im Wechsel durchgefuhrt. Die Ergebnisse konnten einen signifikant groseren Lernzuwachs fur die Li-Re Gruppe gegenuber der R...

Motor learning and cross-limb transfer rely upon distinct neural adaptation processes

Performance benefits conferred in the untrained limb after unilateral motor practice are termed cross-limb transfer. Although the effect is robust, the neural mechanisms remain incompletely understood. In this study we used noninvasive brain stimulation to reveal that the neural adaptations that mediate motor learning in the trained limb are distinct from those that underlie cross-limb transfer to the opposite limb. Thirty-six participants practiced a ballistic motor task with their right index finger (150 trials), followed by intermittent theta-burst stimulation (iTBS) applied to the trained (contralateral) primary motor cortex (cM1 group), the untrained (ipsilateral) M1 (iM1 group), or the vertex (sham group). After stimulation, another 150 training trials were undertaken. Motor performance and corticospinal excitability were assessed before motor training, pre- and post-iTBS, and after the second training bout. For all groups, training significantly increased performance and excitability of the trained hand, and performance, but not excitability, of the untrained hand, indicating transfer at the level of task performance. The typical facilitatory effect of iTBS on MEPs was reversed for cM1, suggesting homeostatic metaplasticity, and prior performance gains in the trained hand were degraded, suggesting that iTBS interfered with learning. In stark contrast, iM1 iTBS facilitated both performance and excitability for the untrained hand. Importantly, the effects of cM1 and iM1 iTBS on behavior were exclusive to the hand contralateral to stimulation, suggesting that adaptations within the untrained M1 contribute to cross-limb transfer. However, the neural processes that mediate learning in the trained hemisphere vs. transfer in the untrained hemisphere appear distinct.