Rapid Error Correction During Human Arm Movements

Studies were made of rapid error correction movements in eight subjects performing a visually guided tracking task involving flexion-extension movements about the elbow. Subjects were required to minimize reaction times in this two-choice task. Errors in initial movement direction occurred in about 3% of the trials. Error correction times (time from initiation to reversal of movement in incorrect direction) ranged from 30-150 ms. The first sign of correction of the error movement was a suppression of the electromyographic (EMG) activity in the muscle producing the error movement. This suppression started as early as 20-40 ms after the initiation of the error-related EMG activity and as much as 50 ms before any overt sign of limb movement. The correction of the error movement was also accompanied by an increase in the drive to the muscle which moved the arm in the correct direction. This increased activity always occurred after the initiation of the error movement. It is concluded that the first step in the error correction, suppression of drive to the muscle producing the error movement, cannot be based on information from the moving limb. It is thus suggested that this earliest response to the error movement is based on central monitoring of the commands for movement.     

Reliability and Specificity of Individual Differences In Reminiscence

In investigating Eysenck’s (1965) suggestion of the specificity of reminiscence, 50 high school boys were tested on 2 gross motorcoordination tasks—one involving tracking and the other balance. In the practice schedule, which was identical for both tasks, all Ss were given 20 50-sec. trials with a 10-sec. intertrial rest. A 5-min. interpolated rest was given after every fourth trial. The reliability of individual differences in reminiscence for both tasks was found to be extremely low. While Eysenck’s hypothesis was not necessarily weakened, doubt was cast upon the specificity of reminiscence in the usual context of the word.     

不同列队呈现方式下反馈对目击证人辨认自信心的影响

采用辨认后反馈范式研究不同队列呈现方式下反馈对目击证人辨认自信心的影响。结果发现：（1）所有辨认者中,反馈组被试自信心显著高于控制组被试的自信心;反馈方式与辨认选择的交互作用显著,辨认选择与列队呈现方式的交互作用显著;（2）积极辨认者中,反馈组被试的自信心显著高于控制组被试的自信心;正确辨认被试的自信心显著高于错误辨认被试的自信心。结果表明：目击辨认中存在辨认后反馈效应;积极辨认者中辨认自信心可以作为辨认准确性的一个参考指标。     

The Reflected Best Self field experiment with adolescent leaders: exploring the psychological resources associated with feedback source and valence

This study provides a preliminary examination of the efficacy of the Reflected Best Self Exercise. We conducted a field quasi-experiment with 108 adolescent leaders assigned to a 2 × 2 design: (1) valence of feedback (i.e., strengths-only versus strengths and improvement-oriented) and (2) source of feedback (i.e., professional (e.g., teachers, coaches, bosses) only versus professional and personal (e.g., friends and family)). By ANOVA, support was found for the hypothesis that feedback from the combination of professional and personal sources is associated with more positive emotional, agentic, and relational resources than feedback from only professional sources. Little support was found for the hypothesis that strengths-based feedback generates more positive emotional, agentic, or relational resources. Limitations, implications for practice and directions for future research are discussed.     

Harnessing members' positive mood for team-directed learning behaviour and team innovation: The moderating role of perceived team feedback

This study examines the role of individual team members' positive mood and perceived team feedback for their team-directed learning behaviour. Results obtained in a sample of 186 members from 27 work teams showed that positive mood was positively associated with team-directed learning behaviour if individual members perceived that the feedback they received was based on the performance of the team as a whole, but not if they perceived such team feedback to be lacking. Moreover, teams were found to be more innovative to the extent that their members, on average, engaged in team-directed learning behaviour to a greater extent. These results offer new insights into the micro-foundations of team learning. Our findings explicate why the contributions of individual members to their team's learning may differ and suggest that, if managed effectively, members' positive mood may be an important resource in facilitating team learning.     

反馈干预对学习判断的影响

将反馈干预作为外部线索引入元记忆研究,采用重复学习任务,在第一轮次学习-测验之后插入反馈干预,用两个实验分别考查任务反馈和能力反馈两种形式下的反馈效价对第二轮次即时学习判断的影响.结果表明：①在学习过程中,学习者会进行自我监测;②在任务反馈形式下,反馈信息与自我监测信息冲突,导致反馈干预对元认知监测和认知过程没有影响;③在能力反馈形式下,反馈信息与自我监测信息的冲突消失,结果消极反馈影响了元认知监测.由此得出结论：只有在不与自我监测信息冲突的情况下,反馈干预才对学习判断产生影响.此外,在有反馈干预的情况下,两个实验中都出现了显著的练习伴随低估效应.     

Symptoms,blood-pressure information and mood effects on symptom recall

Abstract

After completion of an illness symptom checklist (PILL) covering the previous three months, 97 nor-motensives were allocated to either experimental (false pressor feedback, n=42), or information control (accurate pressor feedback, n = 55), groups. The median reported symptom score divided high from low symptom subjects. All were given standard cuff blood pressure (BP) assessment and were normotensive. However, experimental subjects were misinformed that their BP was raised while information control subjects were told their BP was normal. Subsequently, subjects completed the state anxiety form of the State-Trait Personality Inventory, the PILL, and were asked about their belief of the ascribed BP label (normo/hypertensive) and then any perceived causal relationship between their BP and symptoms. Experimental subjects had significantly higher anxiety scores but no change in symptom recall after pressor feedback, whereas control subjects showed lower anxiety scores and decreases in symptom recall.

A post hoc treatment control (no pressor information) group (n = 20) excluded effects of BP labeling on post-BP scores, and a post hoc symptom control group (n = 55) ensured that symptom levels were representative of the normal population. The majority of subjects in both groups rejected any association between BP labels and symptoms. Data are discussed in the light of Leventhal's models of illness representation.     

Challenge Point: A Framework for Conceptualizing the Effects of Various Practice Conditions in Motor Learning

The authors describe the effects of practice conditions in motor learning (e.g., contextual interference, knowledge of results) within the constraints of 2 experimental variables: skill level and task difficulty. They use a research framework to conceptualize the interaction of those variables on the basis of concepts from information theory and information processing. The fundamental idea is that motor tasks represent different challenges for performers of different abilities. The authors propose that learning is related to the information arising from performance, which should be optimized along functions relating the difficulty of the task to the skill level of the performer. Specific testable hypotheses arising from the framework are also described.     

The effects of feedback on the gender differences in the performance in a chronometric mental-rotation test

ABSTRACT

Gender differences favouring males are often found in mental-rotation tests and are usually smaller in chronometric than in psychometric test. The individual feedback in the chronometric test could be an explanation for the comparable performance of males and females. To test this hypothesis, 102 undergraduate students (60 females, 42 males) participated in a chronometric mental-rotation study with or without feedback. A subsample of 41 participants was asked to report their confidence about their performance in the test. In reaction time, males outperformed females and participants in the feedback condition reacted faster than participants without feedback. A significant interaction of gender and condition was found. Only females had an advantage in the feedback condition in reaction time while there was no difference for males. Males reported higher scores of confidence. Feedback seemed to help females especially to react faster. Confidence levels are discussed as reasons for differences between conditions and genders.     

Effects of visual focus and gait speed on walking balance in the frontal plane

We investigated how head position and gait speed influenced frontal plane balance responses to external perturbations during gait. Thirteen healthy participants walked on a treadmill at three different gait speeds. Visual conditions included either focus downward on lower extremities and walking surface only or focus forward on a stationary scene with horizontal and vertical lines. The treadmill was positioned on a platform that was stationary (non-perturbed) or moving in a pattern that appeared random to the subjects (perturbed). In non-perturbed walking, medial–lateral upper body motion was very similar between visual conditions. However, in perturbed walking, there was significantly less body motion when focus was on the stationary visual scene, suggesting visual feedback of stationary vertical and horizontal cues are particularly important when balance is challenged. Sensitivity of body motion to perturbations was significantly decreased by increasing gait speed, suggesting that faster walking was less sensitive to frontal plane perturbations. Finally, our use of external perturbations supported the idea that certain differences in balance control mechanisms can only be detected in more challenging situations, which is an important consideration for approaches to investigating sensory contribution to balance during gait.