Acquisition

Speed and accuracy in the majority of psychomotor tasks studied are typically acquired very rapidly during the early stages of reinforced practice, the average rate of gain tending to drop off as the number of trials or training time increases (Figure 1). Curves based on such measures as reaction time or errors reflect the learner’s improvement by a series of decreasing scores, giving an inverted picture of Figure 1. Tracking scores from the two sexes are seen in Figure 1. Other devices have yielded more complicated functions—e.g., S-shaped curves for complex multiple-choice problems on the selective mathometer (Figure 2). Most acquisition curves obey a law of diminishing returns as high levels of skill are approached. Data such as those from tracking and multiple-choice tasks can be explained by rational mathematical equations derived from theoretical models (see formulas and captions in Figures 1 and 2). Between them, these two equations describe psychomotor acquisition curves from a wide variety of learning situations and of trainees with less than a 2 percent average error of prediction. Contrary to lay opinion, stepwise plateaus of proficiency are seldom seen.

Generalization and transfer

The phenomena of generalization and transfer are seen in the tendency of laboratory subjects conditioned to respond to a particular stimulus to respond as well to similar stimuli beyond the original conditions of training. The measured effects of prior training on the performance of a subsequent task define the transfer of psychomotor learning. In practical skills, transfer is more likely to take place between tennis and badminton, for example, than between swimming and football, and between cornet and trumpet than between piano and tuba. Similarity of movement can facilitate transfer, as can the amount of practice or the sequence of events in previous training. The more the two situations have in common, the greater is the amount of predictable transfer. As differences increase between the stimuli used in training and those encountered on test trials, however, the effects of generalization decrease until there may be no transfer from one situation to another.

Learning one task may facilitate, hinder, or have no observable influence upon performance of the next task, meaning that transfer effects may be positive, negative, or null. Flight simulators are designed to maximize the amount of positive transfer, often by ensuring high levels of behavioral similarity. Negative transfer effects (such as reaching for the floor to shift gears when the shift lever is on the steering wheel) appear occasionally but tend to be easily overcome. Since transfer necessarily involves retention, the best schedules minimize forgetting by minimizing the time between training and transfer.

The degree and amount of transfer are contingent upon such factors as number of common elements or principles, stimulus and response similarity, amount of predifferentiation training, the variety of learning-to-learn experiences, part-to-whole relationships, differences in intertask complexity, use of mnemonic aids, and the extent of proactive or retroactive interference. Retroactive interference designs typically employ a sequence of original learning, interpolated learning, and relearning.

Retention

Learning is to acquisition as memory is to retention. Psychomotor retention scores indicate the percentage or degree of originally learned skill that is remembered or recalled as a function of elapsed time. Alterations of motor memory are identified by changes in means, variances, and correlations between test results. In contrast to verbal behaviour (which is susceptible to forgetting through interference within a matter of seconds), mean scores for tracking and coordination skills recorded over periods ranging from two days to two years diminish scarcely at all. Yet, when intervals of three minutes to six weeks are interpolated between discrete responses on a manual lever device, performance remains stable for about two days and then becomes inconsistent; variabilities increase and correlations decrease as the subjects mis-recall more and more of their original skill. In the light of this evidence, motor memory may be viewed as a phenomenon of persistence, while forgetting is a case of inconsistence.

One hypothesis advanced to account for the greater retentivity of psychomotor behaviour, as compared to that of newly acquired verbal behaviour, is that nonverbal actions are more often overlearned and are less susceptible to proactive interference (i.e., competition arising from things learned in the past). Distinctions between immediate, short-term, and long-term memory are also less prominent in studies of motor learning. This is not to say that motor skills are unforgettable; studies of short-term memory suggest that psychomotor forgetting can be swift indeed. Regardless of theoretical differences, however, psychologists generally agree that psychomotor behaviour is best remembered (and least forgotten) when overlearning is high, interference is low, reinforcing feedback is optimal, and interpolated activities are unrelated to the task being learned. Time is less important in the degradation of memory than are the events that fill the time.

Reminiscence

Reminiscence is defined as a gain in performance without practice. When subjects performing trial after trial without rest (massed practice) are given a short break, perhaps midway through training, scores on the very next trial will show a significant improvement when compared with those of a massed group given no break. Reminiscence effects are most prominent in tasks demanding continuous attention and response. Reminiscence also manifests as a bilateral transfer of skill (e.g., from the left to the right hand), suggesting that this phenomenon is controlled by the central nervous system.

Warm-up

Athletes and musicians often report that they get “cold” during a break from the activity (even for a rest period of a mere five minutes); when practice resumes, a warm-up period appears to be an intrinsic requirement of efficient performance. Wherever reminiscence goes, warm-up seems to follow; yet the converse does not always hold. The connection between warm-up and forgetting is uncertain.

Refractory period and anticipation

When required to make quick, discrete responses to two stimuli separated in time by one-half second or less, an operator’s reaction time (latency) for executing the second response is typically longer than that of his first response. This difference in reaction time is called the psychological refractory period.

Expectancy may occur, for example, when a subject has come to expect a delay between the first and second stimulus, meaning the subject will be relatively unprepared should the second arrive earlier than usual. Furthermore, people learn to expect certain kinds of stimuli over others. Performance declines when a person is uncertain about whether regularly occurring stimuli will be auditory or visual, or when the spatial direction of a stimulus is uncertain. This would suggest the possibility of divided attention; indeed, when pairs of stimuli are made perfectly predictable as to time and type, no impairment of response is observed.

If a subject can acquire suitable expectancies via training and experience, then he can improve the skill of dividing his attention and, within physiological limits, simultaneously handle an increased range of stimuli without a loss of proficiency. Given enough practice, people can reduce the psychological refractory period. A military gunner scanning a distant fixed target for its horizontal and vertical location, for example, is engaging in a preview of receptor anticipation to maximize his score. An operatic soprano who rehearses covertly the opening notes of her cadenza while the orchestra finishes the introduction is employing perceptual anticipation to optimize her performance. Anticipatory timing is learned, and reinforcing feedback is necessary.