Journal of Gerontology 1976, Vol. 31, No. 1, 64-67
Aging and Effect of Physical-Mental Practice Upon Acquisition and Retention of a Motor Skill
Paul R. Surburg, PhD1
The purpose of the study was to determine the effectiveness of physical-mental practice upon two age groups (65-79 and 80-100) in the acquisition and retention of a motor skill. The subjects (140) were randomly assigned to one of the following conditions: physical practice, one-half physical practice, physical-mental practice, or a control group engaging in no practice. Eight trials of IS sec. each on a pursuit rotor were administered prior to and immediately following the practice conditions and 8 weeks later. Analyses of data indicated that for both age groups physical-mental practice was as effective as any other type of physical practice.
Research findings on its usefulness in developing a motor skill are the following: physical practice is superior to mental practice, mental practice groups perform at higher levels than control groups, and mental practice combined with physical practice is equal to or in some instances superior to pure physical practice (Corbin, 1967; Egstrom, 1964; Stebbins, 1968). If mental practice is going to be used in learning a motor skill, it should be combined with physical practice. While the findings of such studies have been utilized to develop motor skill of high school and college age subjects, no research has utilized physical-mental practice with the elderly. The combination method could be a valuable asset for learning and retaining motor skills for the elderly, for there are times when a debilitating condition precludes excessive physical exertion. Physicalmental practice offers one way of reducing physical exertion and allows practice for learning or maintaining a motor skill. An example would be gait training by means of physicalmental practice for an elderly debilitated patient with an orthopedic problem. The purposes of the study were: (a) to investigate the effectiveness of physical-mental practice upon the elderly in the acquisition and retention of a motor skill; and (b) to determine the effect of two different amounts of this type of practice in comparison to physical training in one group, 65 to 79 years of age and a second 80 to 100 years. METHOD
Volunteers (N = 140) from retirement homes in eastern Iowa were selected as subjects. The 'Univ. of West Florida, Pensacola 32504.
64
group consisted of 111 females and 29 males
ranging in age from 65 to 100 with a mean age of 79. No volunteers were included who had any type of paresis, tremor, or ailment of the upper extremity which precluded the execution of a circular motion at the shoulder and elbow. In addition, volunteers who participated in the study had to be able to see a 12-volt light from a distance of 2 ft. Twenty-two subjects did not participate in the retention phase due to illness or death. A Lafayette photoelectric pursuit rotor, model 2203, was employed to measure perceptual motor skill. This tracking task required the subject to keep the end of a stylus on a target rotating at 45 revolutions per minute. When the stylus was in contact with the target, a chronoscope was activated, which recorded time on target. The unit was modified to provide an inverted " L " stand which held a micro-switch suspended 8 in. above the center of the rotor. Depressing the micro-switch activated the pursuit rotor and an interval timer. This timer would stop the pursuit rotor after 15 sec. During tests standardized instructions were read to the subject by one of his peers who directed all testing and practice sessions. The subject sat on a standard folding chair so that the acromion on the dominant hand side of the body was in line with the center of the pursuit rotor. The dominant hand of the subject held the stylus in a handshake grip with the thumb on top of the handle. A trial was initiated when the subject brought the end of the stylus up to the micro-switch and depressed the switch. Thus, a trial started when a subject began the task and not upon command to commence the task. The reason for this procedure was that "it is the interval required be-
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
ENTAL practice is a covert or inM trospective rehearsal of a motor skill.
EFFECT OF PHYSICAL-MENTAL PRACTICE
which engaged only in the testing phase of the study. Following the initial test of eight performance trials, subjects engaged in their respective practice sessions. A final test was given after the completion of the practice sessions; a retention test was administered eight weeks later. The mean time on target for eight trials on the three tests constituted a subject's raw scores. RESULTS
For the initial, final, and retention tests, the intraclass correlation method described by (Ebel, 1951) was used to compute the reliability coefficients of the mean times obtained from the eight trials performed by each subject on the pursuit rotor. Intraclass correlation coefficients were .95, .96, and .97 for initial, final, and retention tests, respectively. Means and standard deviations for each practice condition and each age group are found in (Table 1). In order to determine the effect of practice conditions upon the acquisition of this skill, the data were analyzed two ways: (a) by examining the differences between initial and final test means; and (b) by comparing means of the different practice groups on the final test. The differences between initial and final test means for 7 practice conditions were subjected to a twofactor analysis of variance with practice conditions as a within-subject variable and the two age groups as the between-subject variable. A nonsignificant main effect for age groups (F = 3.23, df = 1/126, p > .05) indicated the rate of improvement was not different between the two age groups. The significant main effect for practice conditions (F = 3.84, df = 6/126, p < .05) and subsequent multiple comparison tests revealed that the improvement of the group receiving physical-mental practice for 14 sessions was significantly better than the control group. No significant differences in improvement were found between groups engaging in 14 practice sessions and those engaging in 7 sessions. The interaction between age and type of practice condition was not significant (F = 0.76, df = 6/126, p > .05). These practice conditions do not seem to be more effective for either the younger or the older age group. A two-factor analysis of variance was employed to determine whether the means of the 7 practice groups on the final test were significantly different. The significant main effect for age (F = 10.64, df = 1/126, p < .05)
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
tween the presentation of a signal and the start of the responding movement which tends to increase with age rather than the time realized to complete the movement once it has begun" (Singleton, 1955). (See also Simon, 1960; Szafran, 1951.) At the end of a 15-sec. performance trial, the interval timer stopped target rotation and started another chronoscope which recorded resting time. Upon completion of each performance trial, the subject rested the dominant hand upon his lap but continued to hold the stylus in the proper grip. With the termination of the rest interval the subject was told to begin the next trial. This was the cue to bring the end of the stylus up to the micro-switch and activate the pursuit rotor. A subject engaged in eight performance trials of 15 sec. each with interpolated rest intervals of 15 sec. Time on target was measured in one-hundredths of a second on a chronoscope located outside the testing room. A practice session for subjects assigned to the physical practice condition involved the same regimen as the testing procedure. Subjects performed eight trials of 15 sec. with 15-sec. rests between trials. In the one-half physical practice condition all procedures were the same as the physical practice condition except that four trials were performed instead of eight trials. The first part of a practice session for the physical-mental practice condition consisted of physically engaging in four trials of 15 sec. each with appropriate rests. During the second part of a practice session, subjects mentally rehearsed the skill for 2 min. without any overt movements. A 10-sec. rest period preceded the last 50 sec. of mental practice. Three groups of subjects engaged in the practice conditions for 7 sessions (phys-7, Vi phys-7, P&M-7) and three groups performed the practice conditions for 14 sessions (phys-14, Vi phys-14, P&M-14). All groups practiced three times a week until the prescribed number was completed. In summary, there were seven practice conditions, six of them experimental, and one control condition. Subjects were divided into two age groups (65 to 79 and 80 to 100) and assigned randomly to one of the following practice conditions: physical practice for 7 sessions (phys7), physical practice for 14 sessions (phys-14), one-half physical practice for 7 sessions (Vi phys-7), one-half physical practice for 14 sessions (Vi phys-14), physical-mental practice for 7 sessions (P&M-7), physical-mental practice for 14 sessions (P&M-14), and a control group
65
66
SURBURG Table 1. Means and Standard Deviations of Performance Scores on Initial, Final, and Retention Tests. Initial Test
Final Test
Retention Test
N
Mean
S.D.
Mean
S.D.
Mean
S.D.
Control
65-79 80-100
10 10
.76 .48
.54 .49
.77 .37
.60 .28
1.16 .55
.70 .40
Physical Practice 7 sessions (phys-7)
65-79 80-100
10 10
.50 .53
.46 .55
2.06 1.06
1.40 1.03
1.49 1.01
.81 .84
One-half Physical Practice 7 sessions ('Aphys-7)
65-79 80-100
10 10
.58 .32
.60 .40
1.32 .76
1.41 .67
.90 .55
.74 .51
Physical and Mental Practice 7 sessions (P&M-7)
65-79 80-100
10 10
1.28 .32
1.14 .27
2.03 1.26
.93 1.28
1.20 1.18
1.08 1.12
Physical Practice 14 sessions (phys-14) One-half Physical Practice 14 sessions ('Aphys-14)
65-79 80-100
10 10
1.05 .52
1.15 .49
2.10 1.20
1.60 1.06
1.90
1.60
.75
.59
65-79 80-100
10
.64
.79
.83
.39
.46
1.28 .66
.89
10
1.20 .66
.98
.84
Physical and Mental Practice 14 sessions (P&M-I4)
65-79 80-100
10 10
.93 .36
.77 .36
2.45 1.53
1.78 2.14
1.50 1.15
.89 1.79
indicated that the younger age group (M = 1.70) performed significantly better than the older age group (M = 0.97). Since the main effect for conditions was also significant (F = 2.86, df = 6/126, p < .05) a multiple comparison analysis was conducted. The group utilizing physical-mental practice for 14 sessions performed significantly better than the control group. The interaction between age and type of practice condition was again not significant (F = 0.15, df = 6/162, p > .05). Age specificity does not seem to be an important factor with these practice conditions. In order to assess the effectiveness of the practice conditions upon retaining a skill, the data were again analyzed in two ways: (a) by examining the differences between retention test and final test means; and (b) by comparing means of the different practice groups on the retention test. Using the differences between the retention and final scores as raw data, a two-factor analysis of variance was performed. A nonsignificant F value for conditions indicated that none of the conditions was found to be more effective in retaining a motor skill (F = 1.94, df = 6/126, p > .05). The significant F value for age groups (F = 7.24, df - 1/126, p < .05) and subsequent examination of means indicated that the older age group (M =7.74) lost less or conversely retained more of this skill than the younger age group (M = 4.44). No significant interaction between age and type of practice conditions were found (F = 1.04, df = 6/126, p>. 05)
An analysis of variance was used to determine whether the means of the seven practice groups on the retention test were significantly different. The nonsignificant F value for practice conditions (F = 1.89, df = 6/126, p > .05) suggested that no significant differences were to be found between types or number of practice sessions. In terms of absolute values the retention of skill was significantly better for the younger age group (M = 1.29) than the older group (M = 0.88) as indicated by the significant F value for age groups (F = 3.93, df = 1/126, p < .05). No significant interaction was found between age and practice groups (F = 0.83, df = 6/126,/?>.O5). DISCUSSION
Analysis of data did not reveal many significant differences between practice conditions. Table 1 would seem to indicate some major differences between physical-mental practice groups and other practice conditions. This apparent contradiction is due to the large variabilities of the practice conditions as examplified by the large standard deviations. A study by Oxendine (1969) utilized mental practice and the pursuit rotor with seventhgrade boys. Eight trials of 15 sec. each constituted the skill test. The standard deviation for the initial test in this study was four times smaller than this measure of variability for the present initial test. It is a known fact that the elderly tend to be more variable in performance than other age groups but in the present study this variability may have confounded the
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
Age Group
CONDITION
EFFECT OF PHYSICAL-MENTAL PRACTICE
SUMMARY
The purpose of the study was to investigate the effectiveness of physical-mental practice upon two age groups (65-79 years of age and 80-100 years) in the acquisition and retention of a physical skill. Mental practice is a conceptualizing or mentally rehearsing of a physical skill. A tracking task on a pursuit rotor was the physical skill which involved attempting to keep a pointer on a light rotating at 45 revolutions per minute. When the pointer was on the light, a clock was activated which recorded time on target. During the testing phase of this study, subjects attempted to stay on the rotating target for 15 sec. This was then followed by a 15-sec. rest period. Eight performance trials of 15 sec. constituted a subject's skill test. Skill tests were administered prior to practice conditions, immediately after the practice conditions and eight weeks later. These tests were referred to as initial, final, and retention tests. For each subject the mean time on target for eight trials on each test constituted the performance score. After the initial test, subjects engaged in their practice conditions. Seventy volunteers in each age group were randomly assigned to six types of practice conditions or a control group which had no practice sessions. The six practice conditions were: (a) physical practice for 7 or (b) 14
practice sessions, (c) one-half the amount of physical practice for 7 or (d) 14 sessions and (e) physical-mental practice for 7 or (0 14 sessions. A practice session for the physical practice condition involved eight performance trials of 15 sec. on the pursuit rotor with 15-sec. rest intervals between trials. Subjects assigned to the one-half physical practice condition engaged in four trials instead of eight trials per session. A physical-mental practice session involved four physical practice trials followed by 2 min. of mentally rehearsing the tracking task. Data were analyzed by comparing the practice condition means on the final and retention tests. Additional analysis involved comparing the differences between initial and final scores and the differences between final and retention test scores for all practice groups and control group. Physical-mental practice for the 14session condition was superior to the control group when differences between initial and final test scores were analyzed and also when final test means were compared. No significant differences were found between physical practice and physical-mental practice or between 7 and 14 sessions. Superiority of a particular practice condition was not found in the retention phase of the analysis. Physical-mental practice did not have a greater effect upon the younger or older age group as evaluated by the final and retention test results. The findings of this study warrant the following conclusion: in both age groups physical-mental practice was as effective as any other type of physical practice for developing or retaining a physical skill. REFERENCES
Corbin, C. B. Effects of mental practice on skill development after controlled practice. Research Quarterly, 1967,35, 534-38. Ebel, R. L. Estimate of the reliability of ratings. Psychometrika, 1951,16, 407-24. Egstrom, G. H. Effects of an emphasis on conceptualizing techniques during early learning of a gross motor skill. Research Quarterly, 1964,35, 472-81. Oxendine, J. B. Effects of mental and physical practice on the learning of three motor skills. Research Quarterly, 1969,40,755-63. Simon, J. R. Changes with age in the speed of performance on a dial setting task. Ergonomics, 1960, 3, 1969-74. Singleton, W. T. Age and performance timing on simple skills. In Old age in the modern world. Livingstone, London,1955. Stebbins, R. J. A comparison of the effects of physical and mental practice in learning a motor skill. Research Quarterly, 1968,39, 714-20. Szafran, J. Changes with age and with exclusion of vision in performance at an aiming task. Quarterly Journal of Experimental Psychology, 1951,3, 111-18.
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
assessment of the efficacy of physical-mental practice. It is also of interest that Oxendine (1969) compared different amounts of physical and mental practice. He found no significant differences among groups using 50, 75, and 100% physical practice. This conclusion supports the present findings. No significant differences were found between physical-mental practice for 7 or 14 sessions and between physical practice for 7 or 14 sessions. He also reported that the retention characteristics of the groups did not differ. This finding is also in agreement with the results from the present study. The findings in this study warranted the following conclusions: physical-mental practice was as effective as any other physical practice condition in the acquisition and retention of a physical skill. Physical-mental practice did not effect the younger age group more than the older age group. No differences were found between the 7 or 14 sessions for any of the practice conditions. The performance of the younger age group was superior to that of the subjects in the older age group.
67
Aging and Effect of Physical-Mental Practice Upon Acquisition and Retention of a Motor Skill
Paul R. Surburg, PhD1
The purpose of the study was to determine the effectiveness of physical-mental practice upon two age groups (65-79 and 80-100) in the acquisition and retention of a motor skill. The subjects (140) were randomly assigned to one of the following conditions: physical practice, one-half physical practice, physical-mental practice, or a control group engaging in no practice. Eight trials of IS sec. each on a pursuit rotor were administered prior to and immediately following the practice conditions and 8 weeks later. Analyses of data indicated that for both age groups physical-mental practice was as effective as any other type of physical practice.
Research findings on its usefulness in developing a motor skill are the following: physical practice is superior to mental practice, mental practice groups perform at higher levels than control groups, and mental practice combined with physical practice is equal to or in some instances superior to pure physical practice (Corbin, 1967; Egstrom, 1964; Stebbins, 1968). If mental practice is going to be used in learning a motor skill, it should be combined with physical practice. While the findings of such studies have been utilized to develop motor skill of high school and college age subjects, no research has utilized physical-mental practice with the elderly. The combination method could be a valuable asset for learning and retaining motor skills for the elderly, for there are times when a debilitating condition precludes excessive physical exertion. Physicalmental practice offers one way of reducing physical exertion and allows practice for learning or maintaining a motor skill. An example would be gait training by means of physicalmental practice for an elderly debilitated patient with an orthopedic problem. The purposes of the study were: (a) to investigate the effectiveness of physical-mental practice upon the elderly in the acquisition and retention of a motor skill; and (b) to determine the effect of two different amounts of this type of practice in comparison to physical training in one group, 65 to 79 years of age and a second 80 to 100 years. METHOD
Volunteers (N = 140) from retirement homes in eastern Iowa were selected as subjects. The 'Univ. of West Florida, Pensacola 32504.
64
group consisted of 111 females and 29 males
ranging in age from 65 to 100 with a mean age of 79. No volunteers were included who had any type of paresis, tremor, or ailment of the upper extremity which precluded the execution of a circular motion at the shoulder and elbow. In addition, volunteers who participated in the study had to be able to see a 12-volt light from a distance of 2 ft. Twenty-two subjects did not participate in the retention phase due to illness or death. A Lafayette photoelectric pursuit rotor, model 2203, was employed to measure perceptual motor skill. This tracking task required the subject to keep the end of a stylus on a target rotating at 45 revolutions per minute. When the stylus was in contact with the target, a chronoscope was activated, which recorded time on target. The unit was modified to provide an inverted " L " stand which held a micro-switch suspended 8 in. above the center of the rotor. Depressing the micro-switch activated the pursuit rotor and an interval timer. This timer would stop the pursuit rotor after 15 sec. During tests standardized instructions were read to the subject by one of his peers who directed all testing and practice sessions. The subject sat on a standard folding chair so that the acromion on the dominant hand side of the body was in line with the center of the pursuit rotor. The dominant hand of the subject held the stylus in a handshake grip with the thumb on top of the handle. A trial was initiated when the subject brought the end of the stylus up to the micro-switch and depressed the switch. Thus, a trial started when a subject began the task and not upon command to commence the task. The reason for this procedure was that "it is the interval required be-
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
ENTAL practice is a covert or inM trospective rehearsal of a motor skill.
EFFECT OF PHYSICAL-MENTAL PRACTICE
which engaged only in the testing phase of the study. Following the initial test of eight performance trials, subjects engaged in their respective practice sessions. A final test was given after the completion of the practice sessions; a retention test was administered eight weeks later. The mean time on target for eight trials on the three tests constituted a subject's raw scores. RESULTS
For the initial, final, and retention tests, the intraclass correlation method described by (Ebel, 1951) was used to compute the reliability coefficients of the mean times obtained from the eight trials performed by each subject on the pursuit rotor. Intraclass correlation coefficients were .95, .96, and .97 for initial, final, and retention tests, respectively. Means and standard deviations for each practice condition and each age group are found in (Table 1). In order to determine the effect of practice conditions upon the acquisition of this skill, the data were analyzed two ways: (a) by examining the differences between initial and final test means; and (b) by comparing means of the different practice groups on the final test. The differences between initial and final test means for 7 practice conditions were subjected to a twofactor analysis of variance with practice conditions as a within-subject variable and the two age groups as the between-subject variable. A nonsignificant main effect for age groups (F = 3.23, df = 1/126, p > .05) indicated the rate of improvement was not different between the two age groups. The significant main effect for practice conditions (F = 3.84, df = 6/126, p < .05) and subsequent multiple comparison tests revealed that the improvement of the group receiving physical-mental practice for 14 sessions was significantly better than the control group. No significant differences in improvement were found between groups engaging in 14 practice sessions and those engaging in 7 sessions. The interaction between age and type of practice condition was not significant (F = 0.76, df = 6/126, p > .05). These practice conditions do not seem to be more effective for either the younger or the older age group. A two-factor analysis of variance was employed to determine whether the means of the 7 practice groups on the final test were significantly different. The significant main effect for age (F = 10.64, df = 1/126, p < .05)
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
tween the presentation of a signal and the start of the responding movement which tends to increase with age rather than the time realized to complete the movement once it has begun" (Singleton, 1955). (See also Simon, 1960; Szafran, 1951.) At the end of a 15-sec. performance trial, the interval timer stopped target rotation and started another chronoscope which recorded resting time. Upon completion of each performance trial, the subject rested the dominant hand upon his lap but continued to hold the stylus in the proper grip. With the termination of the rest interval the subject was told to begin the next trial. This was the cue to bring the end of the stylus up to the micro-switch and activate the pursuit rotor. A subject engaged in eight performance trials of 15 sec. each with interpolated rest intervals of 15 sec. Time on target was measured in one-hundredths of a second on a chronoscope located outside the testing room. A practice session for subjects assigned to the physical practice condition involved the same regimen as the testing procedure. Subjects performed eight trials of 15 sec. with 15-sec. rests between trials. In the one-half physical practice condition all procedures were the same as the physical practice condition except that four trials were performed instead of eight trials. The first part of a practice session for the physical-mental practice condition consisted of physically engaging in four trials of 15 sec. each with appropriate rests. During the second part of a practice session, subjects mentally rehearsed the skill for 2 min. without any overt movements. A 10-sec. rest period preceded the last 50 sec. of mental practice. Three groups of subjects engaged in the practice conditions for 7 sessions (phys-7, Vi phys-7, P&M-7) and three groups performed the practice conditions for 14 sessions (phys-14, Vi phys-14, P&M-14). All groups practiced three times a week until the prescribed number was completed. In summary, there were seven practice conditions, six of them experimental, and one control condition. Subjects were divided into two age groups (65 to 79 and 80 to 100) and assigned randomly to one of the following practice conditions: physical practice for 7 sessions (phys7), physical practice for 14 sessions (phys-14), one-half physical practice for 7 sessions (Vi phys-7), one-half physical practice for 14 sessions (Vi phys-14), physical-mental practice for 7 sessions (P&M-7), physical-mental practice for 14 sessions (P&M-14), and a control group
65
66
SURBURG Table 1. Means and Standard Deviations of Performance Scores on Initial, Final, and Retention Tests. Initial Test
Final Test
Retention Test
N
Mean
S.D.
Mean
S.D.
Mean
S.D.
Control
65-79 80-100
10 10
.76 .48
.54 .49
.77 .37
.60 .28
1.16 .55
.70 .40
Physical Practice 7 sessions (phys-7)
65-79 80-100
10 10
.50 .53
.46 .55
2.06 1.06
1.40 1.03
1.49 1.01
.81 .84
One-half Physical Practice 7 sessions ('Aphys-7)
65-79 80-100
10 10
.58 .32
.60 .40
1.32 .76
1.41 .67
.90 .55
.74 .51
Physical and Mental Practice 7 sessions (P&M-7)
65-79 80-100
10 10
1.28 .32
1.14 .27
2.03 1.26
.93 1.28
1.20 1.18
1.08 1.12
Physical Practice 14 sessions (phys-14) One-half Physical Practice 14 sessions ('Aphys-14)
65-79 80-100
10 10
1.05 .52
1.15 .49
2.10 1.20
1.60 1.06
1.90
1.60
.75
.59
65-79 80-100
10
.64
.79
.83
.39
.46
1.28 .66
.89
10
1.20 .66
.98
.84
Physical and Mental Practice 14 sessions (P&M-I4)
65-79 80-100
10 10
.93 .36
.77 .36
2.45 1.53
1.78 2.14
1.50 1.15
.89 1.79
indicated that the younger age group (M = 1.70) performed significantly better than the older age group (M = 0.97). Since the main effect for conditions was also significant (F = 2.86, df = 6/126, p < .05) a multiple comparison analysis was conducted. The group utilizing physical-mental practice for 14 sessions performed significantly better than the control group. The interaction between age and type of practice condition was again not significant (F = 0.15, df = 6/162, p > .05). Age specificity does not seem to be an important factor with these practice conditions. In order to assess the effectiveness of the practice conditions upon retaining a skill, the data were again analyzed in two ways: (a) by examining the differences between retention test and final test means; and (b) by comparing means of the different practice groups on the retention test. Using the differences between the retention and final scores as raw data, a two-factor analysis of variance was performed. A nonsignificant F value for conditions indicated that none of the conditions was found to be more effective in retaining a motor skill (F = 1.94, df = 6/126, p > .05). The significant F value for age groups (F = 7.24, df - 1/126, p < .05) and subsequent examination of means indicated that the older age group (M =7.74) lost less or conversely retained more of this skill than the younger age group (M = 4.44). No significant interaction between age and type of practice conditions were found (F = 1.04, df = 6/126, p>. 05)
An analysis of variance was used to determine whether the means of the seven practice groups on the retention test were significantly different. The nonsignificant F value for practice conditions (F = 1.89, df = 6/126, p > .05) suggested that no significant differences were to be found between types or number of practice sessions. In terms of absolute values the retention of skill was significantly better for the younger age group (M = 1.29) than the older group (M = 0.88) as indicated by the significant F value for age groups (F = 3.93, df = 1/126, p < .05). No significant interaction was found between age and practice groups (F = 0.83, df = 6/126,/?>.O5). DISCUSSION
Analysis of data did not reveal many significant differences between practice conditions. Table 1 would seem to indicate some major differences between physical-mental practice groups and other practice conditions. This apparent contradiction is due to the large variabilities of the practice conditions as examplified by the large standard deviations. A study by Oxendine (1969) utilized mental practice and the pursuit rotor with seventhgrade boys. Eight trials of 15 sec. each constituted the skill test. The standard deviation for the initial test in this study was four times smaller than this measure of variability for the present initial test. It is a known fact that the elderly tend to be more variable in performance than other age groups but in the present study this variability may have confounded the
Downloaded from http://geronj.oxfordjournals.org/ at Universite Laval on June 29, 2015
Age Group
CONDITION
EFFECT OF PHYSICAL-MENTAL PRACTICE
SUMMARY
The purpose of the study was to investigate the effectiveness of physical-mental practice upon two age groups (65-79 years of age and 80-100 years) in the acquisition and retention of a physical skill. Mental practice is a conceptualizing or mentally rehearsing of a physical skill. A tracking task on a pursuit rotor was the physical skill which involved attempting to keep a pointer on a light rotating at 45 revolutions per minute. When the pointer was on the light, a clock was activated which recorded time on target. During the testing phase of this study, subjects attempted to stay on the rotating target for 15 sec. This was then followed by a 15-sec. rest period. Eight performance trials of 15 sec. constituted a subject's skill test. Skill tests were administered prior to practice conditions, immediately after the practice conditions and eight weeks later. These tests were referred to as initial, final, and retention tests. For each subject the mean time on target for eight trials on each test constituted the performance score. After the initial test, subjects engaged in their practice conditions. Seventy volunteers in each age group were randomly assigned to six types of practice conditions or a control group which had no practice sessions. The six practice conditions were: (a) physical practice for 7 or (b) 14
practice sessions, (c) one-half the amount of physical practice for 7 or (d) 14 sessions and (e) physical-mental practice for 7 or (0 14 sessions. A practice session for the physical practice condition involved eight performance trials of 15 sec. on the pursuit rotor with 15-sec. rest intervals between trials. Subjects assigned to the one-half physical practice condition engaged in four trials instead of eight trials per session. A physical-mental practice session involved four physical practice trials followed by 2 min. of mentally rehearsing the tracking task. Data were analyzed by comparing the practice condition means on the final and retention tests. Additional analysis involved comparing the differences between initial and final scores and the differences between final and retention test scores for all practice groups and control group. Physical-mental practice for the 14session condition was superior to the control group when differences between initial and final test scores were analyzed and also when final test means were compared. No significant differences were found between physical practice and physical-mental practice or between 7 and 14 sessions. Superiority of a particular practice condition was not found in the retention phase of the analysis. Physical-mental practice did not have a greater effect upon the younger or older age group as evaluated by the final and retention test results. The findings of this study warrant the following conclusion: in both age groups physical-mental practice was as effective as any other type of physical practice for developing or retaining a physical skill. REFERENCES
Corbin, C. B. Effects of mental practice on skill development after controlled practice. Research Quarterly, 1967,35, 534-38. Ebel, R. L. Estimate of the reliability of ratings. Psychometrika, 1951,16, 407-24. Egstrom, G. H. Effects of an emphasis on conceptualizing techniques during early learning of a gross motor skill. Research Quarterly, 1964,35, 472-81. Oxendine, J. B. Effects of mental and physical practice on the learning of three motor skills. Research Quarterly, 1969,40,755-63. Simon, J. R. Changes with age in the speed of performance on a dial setting task. Ergonomics, 1960, 3, 1969-74. Singleton, W. T. Age and performance timing on simple skills. In Old age in the modern world. Livingstone, London,1955. Stebbins, R. J. A comparison of the effects of physical and mental practice in learning a motor skill. Research Quarterly, 1968,39, 714-20. Szafran, J. Changes with age and with exclusion of vision in performance at an aiming task. Quarterly Journal of Experimental Psychology, 1951,3, 111-18.
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assessment of the efficacy of physical-mental practice. It is also of interest that Oxendine (1969) compared different amounts of physical and mental practice. He found no significant differences among groups using 50, 75, and 100% physical practice. This conclusion supports the present findings. No significant differences were found between physical-mental practice for 7 or 14 sessions and between physical practice for 7 or 14 sessions. He also reported that the retention characteristics of the groups did not differ. This finding is also in agreement with the results from the present study. The findings in this study warranted the following conclusions: physical-mental practice was as effective as any other physical practice condition in the acquisition and retention of a physical skill. Physical-mental practice did not effect the younger age group more than the older age group. No differences were found between the 7 or 14 sessions for any of the practice conditions. The performance of the younger age group was superior to that of the subjects in the older age group.
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