The interaction of criterion and feedback information in learning a drawing task

Experiments were designed to examine the influence of criterion and feedback information in the learning of a two-dimensional drawing task. Experiment 1 showed that when the task criterion is well known to the subject, the combined presentation of criterion information and information feedback facilitates the rate of acquisition of the skill but not its overall performance level of achievement. Experiment 2 showed that when the task criterion information is not well known to the subject, presentation of criterion information facilitates both the rate of acquisition and the overall performance level and, furthermore, is essential if configuration information feedback is to be utilized effectively. Experiment 3 showed that it is the combined presentation of criterion and configuration information feedback rather than the isolate presentation of either type of information alone, that facilitates learning and performance. Collectively, the findings from the three experiments suggest an interactive effect of prior knowledge by the learner and type of augmented information in facilitating the acquisition of skill, according to the constraints imposed in the task. The data are consistent with the proposal that the degrees of freedom in the information available to support motor skill learning must match the degrees of freedom to be constraint in the perceptual-motor workspace.     

Temporal regularity of tapping by the left and right hands in timed and untimed finger tapping

The temporal characteristics of repetitive finger tapping by the left and right hands were examined in two experiments. In the first experiment, interresponse intervals (IRIs) were recorded while right-handed male subjects tapped in synchrony with an auditory timing pulse (the synchronization phase) and then attempted to maintain the same tapping rate without the timing pulses (the continuation phase). The left and right hands performed separately, at four different rates (interpulse intervals of 250, 500, 750, and 1500 ms). There was no asymmetry of the asynchronies of the timing pulses and the associated responses in the synchronization phase or of the IRIs in either phase, but there was an asymmetry of chronization phase or of the IRIs in either phase, but there was an asymmetry in the temporal dispersion of the responses in both phases. in the second experiment, right-handed males tapped separately with each hand at three different speeds: as quickly as possible, at a fast but steady rate, and at a slow rhythmical rate. The speed asymmetry present when tapping as quickly as possible (with the preferred hand tapping more quickly ) was reduced when tapping at the fast steady rate and was absent when tapping at the slow rhythmical rate. The temporal dispersion of the IRIs produced by the nonpreferred hand was greater than the temporal dispersion of those produced by the preferred hand in all speed conditions. These results show smaller temporal dispersion of tapping by the preferred hand in right-handed males under different conditions, including submaximal speeds at which both hands respond at the same rate. This suggests that the motor system controlling the preferred hand in right-handers had more precise timing of response output than that controlling the nonpreferred hand.     

The effect of motor preparation on changes in h reflex amplitude during the response latency of a warned reaction time task

Monosynaptic Hoffman reflexes (H reflexes) were recorded from the soleus muscle during the response latency of a warned reaction time (RT) task that required plantarflexion of the foot. The task was done under four conditions of predictability of the response signal (RS), created by the factorial combination of foreperiod duration (1 and 4 s) and variability (fixed and variable). RT varied systematically with RS predictability and was facilitated in conditions that favored prediction of the RS. The response latency was divided into two successive phases by the onset of reflex augmentation: a premotor phase of constant reflex amplitude and a succeeding motor phase marked by progressively increasing reflex amplitude. Reflex augmentation during the motor phase was coupled more closely to the imminent movement than to the preceding signal to respond. The duration of the premotor phase was unaffected by RS predictability, but the duration of the motor phase (like RT) was shorter when the RS was more predictable. The maximum H reflex amplitude reached during the motor phase was greater when the RS was more predictable. The tonic level of H reflex amplitude during the premotor phase was greater in conditions that made prediction of the RS difficult. A second experiment showed that this difference was present throughout the foreperiod. These results suggest that conditions that favor prediction of the RS enhance motor preparation. changes in motor preparation (which affect RT) affect the processes underlying reflex amplitudes in the premotor phase and throughout the preceding foreperiod, in conditions that make prediction of the RS difficult, appear to reflect heightened general arousal.     

Preload and isometric force variability

Two experiments are reported, which examined the relative contributions of preload (resting force level), change of force, and the time taken to achieve the force in determining isometric force variability. The findings showed that change of force is the strongest determiner of peak force variability but that preload and time to peak force have smaller though systematic effects. A formula that predicts peak force variability is proposed, with preload as an additive effect to the ratio between the change of force level and the square root of time to peak force. These findings confirm that these three impulse variables are significant in predicting force variability and that the impact of rate of force on peak force variability is nonlinear.     

Category discrimination by pigeons using five polymorphous features

Eight pigeons were trained to discriminate between sets of color photographs of natural scenes. The scenes differed along five two-valued dimensions (site, weather, camera distance, camera orientation, and camera height), and all combinations of the feature values were used. One value of each dimension was designated as positive, and slides containing three or more positive feature values were members of the positive stimulus set. Thus, each feature had an equal, low, correlation with reinforcement, and all features had zero correlations with each other. Seven of the 8 pigeons learned this discrimination, and their responding came under the control of all five features. Within the positive and negative stimulus sets, response rates were higher to stimuli that contained more positive feature values. Once discrimination had been achieved, reversal training was given using a subset of the slides. In this subset, only a single feature was correlated with reinforcement. All pigeons learned this reversal successfully and generalized it to additional photographs with the same feature content. After reversal, the original reinforcement contingencies were reinstated, and training was continued using all the slides except those that had been used in reversal. Reversal generalized to these slides to some extent. Analysis of the response rates to individual slides showed that, compared with prereversal training, only the feature that had been subjected to reversal contingencies showed a reversed correlation with response rate. The remaining features showed the same correlation with response rate as they had before reversal training. Thus, reversal on some members of a category following category discrimination training led to generalization to stimuli within the category that were not involved in the reversal, but not to features that were not reversed. It is therefore inappropriate to refer to the pigeons as learning a concept.     

信号检测论方法引入集值统计试验

集值统计是模糊数学方法的应用,信号检测论之评价法与有无法实验满足集值统计条件,可用集值统计的程度函数表示辨别力或感受性的大小。本文提出两种计算程度函数的数学模型:(1)a=1/K[∑a_(k1·CP_(k1)(Y/SN)+∑a_(k2)·CP_(k2)(Y/N)],(2)f(u)=1/2[∑a_(k1)·P_(k1)(Y/SN)+∑a_(k2)·P_(k2)(Y/N)]。试验结果证实两种模型所计算的程度函数与信号检测论方法所计算的辨别力指数d’有高相关(r_(ad’)=0.842,r_f(u)d’=0.953、n=67),程度函数与d’一样,不仅可以作为辨别力的指标,而且可将判断标准与辨别力分开,不同的是程度函数用β=a_N/a_(SN)或β=f_N(u)/f_(SN)(U)计算的判断标准是一次性综合判断。此点不同于信号检测论可对每一个类别反应的判断标准进行计算。程度函数与d’的计算都利用了对信号与噪音的反应信息。除上述二者的共同之处外,程度函数比d’还具有以下一些优越性:(1)程度函数应用集值统计,无须信号检测论要求对信号与噪音的感觉分布为正态的基本假设,可认为是非参数的方法;(2)可克服信号检测论方法不同判断标准下d’不稳定又难以解释的困难;(3)可适当地减少试验次数;(4)程度函数取值在0-1之间,易于形成量表值方便比较,意义清晰、明确;(5)更符合心理判断的实际状态。     

句子理解的实验研究

在三种不同的条件下,对人验证句子的过程作了比较研究。结果表明,无论在哪种条件下,验证不同类型句子的时间模式是一致的。在句子-图形验证任务中,不管这些图形是抽象的符号还是与常识有关的具体事物的图形,其加工所需的时问基本上是相同的。但是,句子-常识验证所需的时间,要比句子-图形验证的时间明显地短。实验还表明,否定词在句中的位置,对句子的理解有一定的影响。