Bilateral transfer across ages 7 to 17 years

The purpose of this experiment was to determine the effect of age on bilateral transfer. 96 girls, ages 7 to 17 yr., performed 14 trials on a rotary pursuit tracking task (45 rpm, 30-sec. trials, 10 sec. between trials). Half of the subjects performed the first seven trials with the preferred hand, using the nonpreferred hand on the subsequent seven trials. The order was reversed for the other subjects. There were no significant differences between groups in initial scores or in increases in time on target over the first seven trials, supporting the hypothesis that this was a novel task. There was an increase in time on target across ages and age influenced bilateral transfer, with older girls profiting more from the other-hand practice. Transfer was greater from preferred to nonpreferred than the reverse.     

Timing and force components in bilateral transfer of learning

Bilateral transfer of perceptual and motor components in movement control was investigated through two experiments. In Experiment 1 a simple anticipatory timing task was practiced with either the preferred or the nonpreferred hand. After a short resting interval an additional set of trials was performed with the contralateral hand. In Experiment 2, the same experimental design was used to investigate bilateral transfer of fine force control in a wrist-flexion movement. Analysis of the results showed that bilateral transfer of learning took place for both anticipatory timing and force control, with more noticeable transfer of training for the former. Asymmetry in transfer was found for force control, with significant transfer only in the preferred-to-nonpreferred direction. Transfer of anticipatory timing occurred similarly in both directions. These results indicated anticipatory timing as a powerful component for bilateral transfer, while force control showed to be more dependent on practice with the specific muscular system.     

Effects of blocked versus random practice by mentally retarded subjects on learning a novel skill

The purpose of this study was to assess the effects of different practice conditions on mentally retarded subjects learning a novel task. 20 subjects with a mean IQ of 51.82 were randomly assigned to one of two practice conditions. The first group practiced at three different speeds (60, 30, and 15 rpm) on the pursuit rotor using a block arrangement in which each speed was practiced for five consecutive trials of 20 sec. duration before practicing at the next speed. The second group used random practice performing 15 trials of the pursuit rotor so three speeds were randomly distributed over the 15 trials. Both groups on the next day performed 15 trials of 20 sec. duration on the pursuit rotor at the transfer speed of 45 rpm. Analysis showed no significant differences among practice conditions which provided 10 min. of experience prior to test.     

Varied Input Stimuli and Motor Learning,

75 apparatus-naive undergraduate Ss were assigned to one of five groups differentiated according to training display associated with a modified rotary pursuit (RP) apparatus. Performance of two control groups, one practicing an unaided reference task and the other a pathmarked RP task, was compared with that of groups that received either path-marked or mechanically guided practice during training, and where path-marked and mechanical guidance display was removed during transfer. It was found that the path-marked display produced superior results only during initial stages of practice, and retarded improvement in performance after transfer to the reference task. Mechanical guidance resulted in better performance on the path-marked condition than the unaided RP task, but in both cases performance dropped upon transfer. The results are discussed in the light of hypothesized learning strategies influenced by different training conditions.     

Skill, strength, handedness, and fatigue

Thirty male subjects, 20 of whom were self-classified left-handers and 10 right-handers, were tested on a grip-strength task and a handwriting task with each hand, both under normal conditions and in a situation of induced experimental fatigue. On the basis of questionnaire scores, the left-handers were sub-divided into two groups comprising the 10 most left-handed and the 10 least left-handed subjects. The test of grip strength showed a small but significant deterioration in performance of both hands from fatigue. With the handwriting task, a similar significantly adverse effect of fatigue was recorded for all groups as well as a large significant difference in performance between the preferred and nonpreferred hands under normal conditions, which decreased under fatigue. An explanation of these differential effects is discussed in terms of the greater efficiency of the preferred hand in the highly developed skill of handwriting.     

Retention of bilateral performance as a function of practice order

The purpose of this study was to investigate the effect of practice order and initial performance hand on the bilateral retention of a simple tracking skill for 44 undergraduate volunteers. The apparatus was a Lafayette Model 30014 photoelectric rotary pursuit. The circle template was employed with rotation speed set at 20 rpm. Subjects were given 20-sec. trials and required to reach a criterion of 70% time on target twice in succession with both hands. For original practice, subjects were randomly assigned to one of four practice groups: preferred serial, non-preferred serial, preferred sequence and non-preferred sequence. Subjects' performance was recorded as the number of trials required to achieve criterion for both hands. One month later subjects were retested and scored in the same manner. A 2 X 2 X 2 analysis of variance with repeated measures on the last factor was used to determine the effects of initial hand, order of practice, testing periods, and the appropriate interactions. The results indicated that subjects' performance for the two testing periods differed significantly; retest was superior. Order of practice was significant and the sequential order more efficient during both learning and retest.     

Control in memory for movement cues by mentally retarded children

The study was designed to determine the desirability of providing external prompts (1) to use a mnemonic to enhance accuracy of recall and (2) to use response 'priming' in memory for spatial location by mentally retarded persons. Two groups of 40 mentally retarded boys and girls and two groups of 40 MA-matched nonretarded children were compared for accuracy in the recall of movement on an arm-positioning task. No differences were found between mentally retarded subjects and MA-matched subjects treated under the same conditions. However, all groups were unable to make spontaneous control adjustments to accommodate the covert manipulations made just prior to recall. By providing response primes, appropriate performance adjustments were made by all groups, resulting in a significant improvement in accuracy of recall. These findings serve to reaffirm earlier reports showing remarkable similarity between the mentally retarded and MA-matched nonretarded subjects.     

Hand preference in simultaneous unimanual tasks: a preliminary examination

The aim of the current investigation was to determine the pattern of hand use during simultaneous unimanual tasks. Two studies were conducted. The first experiment examined the pattern of hand use in a catching task, while performing a secondary writing task. Results showed that individuals had a decreased tendency to catch with their preferred hand when their preferred hand was occupied, in comparison to when the preferred hand was unoccupied. The second experiment examined the pattern of hand use during a support and reach task, where the use of both hands was required. Here, results indicated that participants preferred to support themselves with their nonpreferred hand and reach with preferred hand toward right hemispace. With respect to left hemispace, participants showed the reverse pattern. This pattern of hand use indicates an important role for the nonpreferred hand, which has been relatively unexplored by researchers.     

New methodology applied to bonnet macaques (Macaca radiata) to address some contradictory evidence on manual asymmetries in Old World monkeys

Seven bonnet macaques (Macaca radiata) with strong hand preferences in performing a computer-generated joystick task that required directing a cursor to contact a small stationary target on a monitor were given comparable experience with each hand on the task over a 5-week period. Hand use was randomly restricted to either only the left or only the right hand across trials by automatically inputting into a computer the unique identification numbers of microchips implanted in the forearms of each macaque. Subsequent presentation of a novel task requiring maintenance of contact between a cursor and a moving target revealed no performance difference between preferred and nonpreferred hands or between left and right hands on the basis of number of errors or time to complete the task. The findings suggest that the strong hand preference for these tasks does not derive from a performance advantage for the preferred hand.     

Emergent simple discrimination in children: Preference for non-preferred stimuli

Previous research (Smeets, 1991) suggested that when given a new discrimination, children respond on the basis of physical similarity with previously discriminated stimuli. They respond to a stimulus similar to another preferred stimulus (S+ transfer) and respond away from a stimulus similar to another nonpreferred stimulus (S- transfer). When both types of transfer apply to the same stimulus, S+ transfer prevails, S+ Priority Transfer (S+PT). The present study demonstrated that S+PT also occurs when the criterion task consists of two nonpreferred stimuli. When given a choice between two previously nonpreferred stimuli, one similar and one dissimilar to other preferred stimuli, children select the first one. They do not so, however, when a nonpreferred stimulus resembling another preferred stimulus is presented with a new nonpreferred stimulus. These findings suggest that the children's preferences were not based on the physical resemblance with other (non)preferred stimuli but on the functions (S+, S-, S0) of individual stimulus components. A theoretical model is presented that accounts for all experimental data reported in the previous and present study. The model implies that discriminative responding not only results from but also determines the functional properties of individual stimulus elements.     

Mechanism Involvement During Skill Imagery

Explanations of the effects of initial mental imagery practice on the subsequent performance of a motor task may be divided into two categories. Inflow explanations propose that proprioceptive feedback generated during imagery practice serves as the underlying mechanism while outflow explanations claim that cognitive operations (e.g., motor programs) generated during skill imagery serve as the basis for physical performance. A test of these two models was conducted by comparing unilateral and bilateral transfer in a rotary pursuit task following either imagery or physical practice (cf. Wallace, 1977). The results showed that all transfer groups produced positive transfer relative to a no-practice control group. Further, unilateral transfer was greater than bilateral transfer for physical practice. There was no difference between unilateral and bilateral transfer for imagery practice. These data were interpreted as evidence for an outflow explanation of skill imagery.     

Mechanism involvement during skill imagery

Explanations of the effects of initial mental imagery practice on the subsequent performance of a motor task may be divided into two categories. In-flow explanations propose that proprioceptive feedback generated during imagery practice serves as the underlying mechanism while outflow explanations claim that cognitive operations (e.g., motor programs) generated during skill imagery serve as the basis for physical performance. A test of these two models was conducted by comparing unilateral and bilateral transfer in a rotary pursuit task following either imagery or physical practice (cf. Wallace, 1977). The results showed that all transfer groups produced positive transfer relative to a no-practice control group. Further, unilateral transfer was greater than bilateral transfer for physical practice. There was no difference between unilateral and bilateral transfer for imagery practice. These data were interpreted as evidence for an outflow explanation of skill imagery.     

Effects of massed versus distributed practice on gross and fine motor proficiency of educable mentally handicapped adolescents

Gross and fine motor proficiency were studied in a sample of 52 educable mentally handicapped students (M = 15.8 yr.), half of whom were assigned to 15 30-sec. trials, a relatively massed practice schedule with 5 sec. between trials, and half to a distributed practice schedule with 30-sec. rests. 5 trials were given 24 hr. later. All subjects performed the stabilometer balance task to measure gross motor proficiency and a 45-rpm pursuit rotor task to measure fine motor proficiency. No significant differences with regard to the practice schedule used early in learning were found, however, boys scored significantly higher on the pursuit rotor than girls.     

Bilateral symmetry in coincident timing: a preliminary investigation

The purpose of this study was to investigate the coincident timing accuracy of the preferred and nonpreferred limbs in a ballistic striking task. A secondary purpose was to examine subjects' perception of their performance proficiency with each limb. 30 right-hand preferred subjects performed a 60-cm horizontal arm motion to displace a wooden barrier in coincidence with the final light in a series that traveled down a runway. Interestingly, while both the preferred and nonpreferred limbs were equally proficient in temporal accuracy, 80% of subjects perceived a bilateral asymmetry in performance. The influence of this perception on bilateral skill performance and acquisition remains in question.     

Gross Motor Performance in Minimally Brain Injured Children

As a pre-requisite to curriculum development, the characteristics of the gross motor performance of special education classes of minimally brain injured boys and girls were described. In general, age changes in mean performance were linear, the scores of the boys being the superior. The level of performance very closely resembled that of comparison groups of educable mentally retarded children from the same school districts.     

Knowledge and behavior relationships in the memory ability of retarded and nonretarded students

Twenty mildly mentally retarded adolescents were matched with two groups of nonretarded students, one of the same chronological age (CA 16) and the other of the same mental age (MA 9), to examine the influence of age and metamemory on recall. This was achieved using an adapted metamemory instrument which included relevant recall tasks. Recall scores showed that when tasks exhibited some organizational features, the retarded group was as accurate as their CA counterparts; when tasks were less organized, they responded much like their MA counterparts. Regression analyses indicated that, depending on task characteristics, chronological age emerged as a significant predictor of recall in certain situations, and in others, mental age accounted for more variance. Metamemory responses in one task accounted for more variance than either CA or MA.     

Preliminary data on a computerized test of finger speed and endurance

We set out to develop a computer-assisted finger-tapping task (the T3) that would measure motor speed much like the Reitan test, but that would also measure endurance. Data were collected for a convenience sample on both the T3 and the Reitan finger-tapping test. Moderate and significant correlations were obtained between the T3 and the Reitan test for both hands. Mean scores for the first 50 sec of the T3 were approximately 0.15 taps greater than the mean Reitan score for both the preferred and the nonpreferred hands, while the mean scores for the full 2 min of the T3 were 1.52 taps less than those of the Reitan test for the preferred hand, and 1.32 taps less for the nonpreferred hand. The mean for the last 40 sec with the preferred hand averaged 3.93 taps (7.62%) slower than for the first 40 sec, whereas for the nonpreferred hand, the difference was 5.12 taps (11.15%). These results are consistent with our intent to develop measures of (1) relatively pure motor speed (the first 50 sec of the T3); (2) motor speed combined with endurance (the full 2 min of the T3); and (3) finger endurance (the first 40 sec compared with the last 40 sec of the T3).     

GENERALIZATION AND TRANSFER BETWEEN COMPREHENSION AND PRODUCTION: A COMPARISON OF RETARDED AND NONRETARDED PERSONS

The study compared the acquisition, generalization, transfer, and maintenance of language comprehension and production responses by persons at two IQ levels: mentally retarded (N = 10) and nonretarded (N = 10). The two levels of the IQ Level factor were combined factorially with two levels of a Training Condition factor: Comprehension-Production and Production Only. Participants in the former groups were trained sequentially to (a) comprehend coin labels by pointing, and then (b) produce verbally the correct coin label. Participants in the Production Only groups were trained on the latter response only. A three-factor mixed design with one repeated measure plus a multiple baseline across coin responses was employed. Results indicated that both mentally retarded and nonretarded subjects attained a high level of acquisition and maintained their performance on 1- and 4-week follow-up tests. No difference occurred between mentally retarded and nonretarded participants in magnitude of acquisition, but the mentally retarded groups took approximately three times as many trials to complete training. Data also suggested, contrary to past research, that generalization from comprehension to production was bidirectional, with no difference in magnitude between mentally retarded and nonretarded subjects. Transfer from comprehension to production occurred in both nonretarded and retarded subjects; comprehension training facilitated a savings of trials in production training. These results show that language differences between retarded and nonretarded persons are quantitative rather than qualitative as some past research may have suggested.     

Finger tapping: effects of trials and sessions

18 normal, self-reported dextral subjects (9 men, 9 women) were assessed with a Halstead Manual Finger Tapping device, with 10 trials per hand for 10 consecutive wk. The test-retest reliability of the 10-trial average between the 10 sessions averaged .94 for men and .86 for women, for both preferred and nonpreferred hands. There were no statistically significant effects of increases in performance over sessions or effects of fatigue over trials for either sex or hand. There were, however, significant increases over trials for men for both preferred and nonpreferred hands.     

Perceptual learning by educable mentally retarded, average, and gifted children of primary school age

A match-to-sample task and a preference-ranking procedure were used to provide predifferentiation experiences on a color discrimination for 6- and 8-yr.-old children. The subjects included an educable mentally retarded 8-yr.-old group, an average 8-yr.-old group, a gifted 6-yr.-old group, and an average 6-yr.-old group. Mental age was the best predictor of success on task. A significant interaction of sex and teaching method suggests an advantage of girls in this group in instructional situations in which the perceptual learning task and testing tasks are not exactly the same. Girls did better than boys when a different response for task content was required in testing from that in teaching. Boys and girls performed similarly when the training task was the same as the testing task.