Effect of using mechanical devices for baseball batting on warm-up decrement

The extent to which different mechanical baseball-batting devices used during a rest affected performance immediately after rest (warm-up decrement) was examined. Difference scores between the average of prerest Trials 8, 9, and 10 and each of 10 postrest trials were used to determine the presence of warm-up decrement. It was predicted that the use of a batting-T and the Batter's Aid machine (in which a batter swings at a ball popped up within the strike zone) would result in superior performance measured as the distance (ft.) a ball was hit and frequency of contacts on postrest performance reducing or eliminating the warm-up decrement. Performance of 33 boys, aged 11 and 12 yr., indicated that only use of the Batter's Aid eliminated warm-up decrement with respect to both the distance and frequency as compared to the batting-T and control groups. In addition, the batting-T condition solicited significantly better performance than the controls on the distance measure but was statistically similar to the controls in frequency of contacts. Also, superior performance was significantly related to heightened heart rate, a physiological index of arousal. A primary explanation of the results focused on the effects of heightened physiological and psychological arousal on warm-up decrement.     

The use of positively-worded performance reminders to reduce warm-up decrement in the field hockey penalty shot

Abstract

The effect of performance reminders in reducing temporary posttest performance decrement, referred to as warm-up decrement (WUD), was examined. Advanced, male, held hockey players performed 21 baseline trials of the standard penalty shot and then rested for three 7-min periods, each of which was followed by 4 additional penalty shots. During the last 2 min of each rest period, control participants continued resting while participants in 2 other groups reviewed written checklists containing positively-worded (PR) performance reminders (e.g., “watch the ball”) or negatively-worded (NR) reminders (e.g., “don't rush the shot”). Diminished posttest performance accuracy and movement form (i.e., WUD) was found for the NR group and control group but not for the PR group. It was concluded that the review of positively-worded performance reminders may be an effective warming-up activity for certain types of discontinuous sport performance.     

Evidence for graded central processing resources in a sequential movement task

In the present experiment, we examined slowing of the individual key presses of a familiar keying sequence by four different versions of a concurrent tone counting task. This was done to determine whether the same cognitive processor that has previously been assumed by the dual processor model (DPM) to initiate familiar keying sequences and assist in their execution, is involved also in the central processes of a very different task (viz. identifying tones and counting target tones). The present results confirm this hypothesis. They also suggest that in this particular situation the central processing resources underlying the cognitive processor can be distributed across the central processes of different tasks in a graded manner, rather than that they continue to behave like a single, central processor that serially switches between the central processes of the concurrently performed tasks. We argue that the production of highly practiced movement sequences can be considered automatic in the sense that execution of familiar movement sequences can continue without cognitive control once they have been initiated.     

Evidence for model-based action planning in a sequential finger movement task

In this article, the authors examine whether and how humans use model-free, reflexive strategies and model-based, deliberative strategies in motor sequence learning. They asked subjects to perform the grid-sailing task, which required moving a cursor to different goal positions in a 5 × 5 grid using different key-mapping (KM) rules between 3 finger keys and 3 cursor movement directions. The task was performed under 3 conditions: Condition 1, new KM; Condition 2, new goal position with learned KM; and Condition 3, learned goal position with learned KM; with or without prestart delay time. The performance improvement with prestart delay was significantly larger under Condition 2. This result provides evidence that humans implement a model-based strategy for sequential action selection and learning by using previously learned internal model of state transition by actions.     

Gender-specific movement strategies using a computer-pointing task

Females typically demonstrate a movement time advantage for tasks requiring high levels of manual dexterity, whereas males are notably better at targeting activities. According to D. Kimura (2000), the hunter-gatherer hypothesis primarily accounts for those performance advantages; that dichotomy fails, however, when one makes movement outcome predictions for tasks that are not clearly fine-motor or interceptive in nature. Investigators have recently proposed that time constraints (M. Peters, 2005) and gender-specific response style differences (M. Peters & P. Campagnaro, 1996; L. E. Rohr, 2006) affect motor performance. Here, the author used a computer-pointing task measuring both movement error and movement time in 16 participants to further investigate response style differences. Kinematic and linear regression analyses between resultant error and both movement time and task difficulty reinforced the notion that gender-specific movement biases emphasize speed and accuracy, respectively, for men and women.     

Error detection and correction in a structured movement task

Error-detection and error-correction experiments were conducted to examine the assumption that organizational processes play an important role in motor learning and control. During the initial phase of each experiment, the sensory aspects of five movements were held constant while the organizational structure (sequential vs. random) of the movements was varied. In the learning phase of both experiments, the effect of organization produced increased reproduction accuracy for the structured movement sequences compared to those that were random. This benefit of organization carried over into the error detection and correction parts of the experiments where it was shown that improved error detection and correction capabilities were assisted by the manner in which the movements were presented. The importance of cognitive processes is discussed in terms of past and contemporary accounts of motor learning and control.     

Improving balance by performing a secondary cognitive task

Contrary to general findings in the attention and memory literature, some studies have shown that performing a secondary cognitive task produces an improvement in balance performance. The purpose of the present experiment was to investigate under what condition such an improvement would occur. Young and older adults were asked to hold as still as possible on a platform that measured sway while performing or not performing the encoding phase of the Brooks' (1967) spatial or non‐spatial memory task. The difficulty of maintaining balance was manipulated by varying the availability of visual input and sway‐referenced motion of the platform. Sway scores were computed based on the distance between the individual pressure centres and the average centre of pressure during each 20‐s trial. The results indicated that both the spatial and non‐spatial memory tasks improved balance for older adults under the most difficult balance condition.     

The one-target advantage: a test of the movement integration hypothesis.

Two experiments were conducted to compare the temporal structure of single aiming movements to two-component movements involving either a reversal in direction or an extension. For reversal movements, there was no cost associated with the movement time for the first segment of the movement. However, regardless of movement direction, initiation instructions, handedness or effector, two-component extension movements were always associated with a longer movement time for the first movement segment. This disadvantage for extension movements, but not reversal movements, is consistent with the notion that there is interference between the execution of the first movement and implementation of the second movement. By contrast, because the muscular force used to break the first movement is also used to propel the second movement, reversal movements are organised as an integrated unit.     

Semantic interference in a delayed naming task: evidence for the response exclusion hypothesis

In 2 experiments participants named pictures of common objects with superimposed distractor words. In one naming condition, the pictures and words were presented simultaneously on every trial, and participants produced the target response immediately. In the other naming condition, the presentation of the picture preceded the presentation of the distractor by 1,000 ms, and participants delayed production of their naming response until distractor word presentation. Within each naming condition, the distractor words were either semantic category coordinates of the target pictures or unrelated. Orthogonal to this manipulation of semantic relatedness, the frequency of the pictures' names was manipulated. The authors observed semantic interference effects in both the immediate and delayed naming conditions but a frequency effect only in the immediate naming condition. These data indicate that semantic interference can be observed when target picture naming latencies do not reflect the bottleneck at the level of lexical selection. In the context of other findings from the picture-word interference paradigm, the authors interpret these data as supporting the view that the semantic interference effect arises at a postlexical level of processing.     

Generalization decrement and not overshadowing by associative competition among pairs of landmarks in a navigation task

When they are trained in a Morris water maze to find a hidden platform, whose location is defined by a number of equally spaced visual landmarks round the circumference of the pool, rats are equally able to find the platform when tested with any two of the landmarks (Prados, & Trobalon, 1998; Rodrigo, Chamizo, McLaren, & Mackintosh, 1997). This suggests that none of the landmarks was completely overshadowed by any of the others. In Experiment 1 one pair of groups was trained with four equally salient visual landmarks spaced at equal intervals around the edge of the pool, while a second pair was trained with two landmarks only, either relatively close to or far from the hidden platform. After extensive training, both male and female rats showed a reciprocal overshadowing effect: on a test with two landmarks only (either close to or far from the platform), rats trained with four landmarks spent less time in the platform quadrant than those trained with only two. Experiment 2 showed that animals trained with two landmarks and then tested with four also performed worse on test than those trained and tested with two landmarks only. This suggests that generalization decrement, rather than associative competition, provides a sufficient explanation for the overshadowing observed in Experiment 1. Experiment 3 provided a within-experiment replication of the results of Experiments 1 and 2. Finally, Experiment 4 showed that rats trained with a configuration of two landmarks learn their identity.     

Motion coordination affects movement parameters in a joint pick-and-place task

This study examined influences of social context on movement parameters in a pick-and-place task. Participants' motion trajectories were recorded while they performed sequences of natural movements either working side-by-side with a partner or alone. It was expected that movement parameters would be specifically adapted to the joint condition to overcome the difficulties arising from the requirement to coordinate with another person. To disentangle effects based on participants' effort to coordinate their movements from effects merely due to the other's presence, a condition was included where only one person performed the task while being observed by the partner. Results indicate that participants adapted their movements temporally and spatially to the joint action situation: Overall movement duration was shorter, and mean and maximum velocity was higher when actually working together than when working alone. Pick-to-place trajectories were also shifted away from the partner in spatial coordinates. The partner's presence as such did not have an impact on movement parameters. These findings are interpreted as evidence for the use of implicit strategies to facilitate movement coordination in joint action tasks.     

Movement observation affects movement execution in a simple response task

The present study was designed to examine the hypothesis that stimulus-response arrangements with high ideomotor compatibility lead to substantial compatibility effects even in simple response tasks. In Experiment 1, participants executed pre-instructed finger movements in response to compatible and incompatible finger movements. A pronounced reaction time advantage was found for compatible as compared to incompatible trials. Experiment 2 revealed a much smaller compatibility effect for less ideomotor-compatible object movements compared to finger movements. Experiment 3 presented normal stimuli (hand upright) and flipped stimuli (hand upside-down). Two components were found to contribute to the compatibility effect, a dynamic spatial compatibility component (related to movement directions) and an ideomotor component (related to movement types). The implications of these results for theories about stimulus-response compatibility (SRC) as well as for theories about imitation are discussed.