Relationship between Intelligence and the Effect of Mental Practice on the Performance of a Motor Skill

Thirty-five boys were given nine periods, each of five minutes duration, of mental practice at the underarm basketball free throw. They were tested for accuracy of throwing before and after the mental practices. The significant gain obtained could not be related to the initial score or to the intelligence of the thrower. EARLY RESEARCH BY Freeman (2) indicated that mental work was accompanied by variations in muscle tensions. From this he concluded that “photographic registration of the thickening of several muscle groups provided valid and important evidence of the spread of neuromuscular activity during mental work.” Later work by Shaw (4) showed that there was an involuntary muscle activity accompanying the mental practice of a motor skill. Buxton (1), in a publication from a survey of the literature on reminiscence, noted that greater improvement in skilled performance after practice occurred if intervals of rest were allowed between the tests and concluded that this benefit was the result of reminiscence. Vandell (7) and Twining (6), working individually, concluded that mental practice probably improves the performance of a motor skill. Morrisson (3), in his book Better Golf without Practice, thinks that mental practice does improve performance at golf. In 1952 Steel (5) tested the effects of mental practice on motor learning in such a way as to enable statistical treatment of the data. He found that mental practice did not improve a ball-throwing skill to a statistically significant degree but concluded that “daily mental practice of a motor skill produces a substantial increase in that skill.”