Practice evoking the flexor carpi radialis h-reflex: a guideline for proficiency

The purpose of this research was to identify the number of sessions required for a new investigator to become proficient at evoking an H-reflex in the flexor carpi radialis (FCR), in comparison to an experienced investigator. 31 students from Brock University in the greater Niagara region (16 women M age = 32.2, SD = 8.9 yr.; 15 men M age = 27.8, SD = 7.8 yr.) with no known neurological disorders volunteered and completed two test sessions performed by either an experienced or a novice investigator. In randomized order, both investigators stimulated each subject's median nerve 10 times, once every 15 sec. Each session included the measurement of the subject's flexor carpi radialis maximal M-wave amplitude and H-reflex amplitude and latency with surface electromyographic electrodes. The intraclass correlation coefficients (ICC) indicated an adequate correlation between investigators for both M-wave maximal amplitude and H-reflex at 5% of the M-wave maximal amplitude (.84 and .70, respectively). However, there was a low correlation (.38) between the latency values obtained by the two investigators. The peak-to-peak amplitudes of the H-reflex and M-wave do not appear to be influenced by experience of the tester. The latency of the response, however, appears to have an associated learning curve, improving in consistency with increasing practice of tester.     

Pictorial concreteness and mode of elaboration in children's learning

Paired-associate learning by children was investigated as a function of age (4 vs 7 yr), stimulus type (line drawing, color photograph, or object) and mode of elaboration (visual or verbal). Photographs and objects were associated with more learning than drawings at both ages and with both types of mediational elaboration. Only indirect evidence could be obtained for the prediction that differences among the three types of pictorial stimuli decrease with age. A previously reported Age × Elaboration interaction suggesting a relative disadvantage of visual elaboration for the younger children was not replicated.     

Voice initiation and termination time in stuttering and nonstuttering children

Voice initiation time (VIT) and voice termination time (VTT) was measured in seven stuttering and eight nonstuttering children ranging in age from 4 yr, 6 mo to 6 yr, 10 mo. The experimental task was the production of /a/ in response to a 1000-Hz pure tone. Voice initiation time was defined as the period of time elapsing between the onset of the auditory stimulus and the onset of the subject's response of /a/, as displayed on an oscilloscope. Voice termination time was defined as the latency between termination of the stimulus tone and the point at which the oscilloscopic signal decreased by 90%. No statistically significant differences were found between the two groups with respect to either VIT or VTT. In addition, no apparent relationships were present among VIT, VTT, or stuttering severity.     

The effect of failure and frustration on reflective and impulsive children

Failure was hypothesized to be an antecedent of a reflective style of responding and frustration an antecedent of an impulsive style. Failure and frustration were manipulated with an anagrams task and their effect on latency and errors on the Matching Familiar Figures Test (MFF) was assessed. The Failure group increased its latency on the MFF, replicating Messer's (1970) research, while the Frustration group showed a nonsignificant decrease in latency. There was a relation between an increase in latency and a decrease in errors on the MFF. The findings were related to research on the “frustration effect” in children and were interpreted as suggesting the need for research on the effects of the amount and patterning of failure on reflection-impulsivity.     

Tactile discrimination, response mode, and interhemispheric communication by learning disabled children.

32 right-handed, learning disabled children aged 8-10 yr., 11-13 yr., and 14-16 yr. were presented a tactile discrimination task. Pairs of fabrics of different or the same texture were presented to the same hand (uncrossed condition) or alternating hands (crossed condition). Discrimination errors were compared using a verbal response mode and a nonverbal response mode. Analysis indicated that the number of crossed errors was significantly greater in the verbal response mode than in the nonverbal response mode for only the youngest children. These results suggest selective attention-activation bias and/or hemispheric processing limitations for younger learning disabled children.     

Preliminary remarks on type of task and delay in children's prospective memory

This study investigated the extent to which the type of task influences children's prospective memory performance. 80 subjects, aged 7 to 11 yr. participated in an experiment in which the type of task (time-based vs event-based) and the retention interval (5 min. vs 10 min.) varied. The prospective memory task was embedded in a principal task lasting about 15 min. and required subjects perform an action at a given time or in response to a specific cue. Analysis indicated that the delay was associated with prospective memory performance only on a time-based task in which the intention has to be performed after 10 min. but not age. Analysis indicated also that time monitoring was associated with shorter latency between the target time and the execution of the intention on the time-based task. Implications were discussed.     

The effects of stimulus movement and attention on peripheral stimulus localization by 8- to 26-week-old infants

This study examined the effect of stimulus movement on localization probability and latency during attention and inattention. Forty infants, 10 each at 8, 14, 20, and 26 weeks of age were presented with a central stimulus. Then, a peripheral stimulus was presented (static or dynamic checkerboard). Stimulus movement did not affect localization probability. Infants localized the dynamic peripheral stimulus more quickly than the static peripheral stimulus when there was no focal stimulus. Focal stimulus attention attenuated this difference in localization latency between static and dynamic stimuli. Signal detection analysis showed that sensitivity to the peripheral stimulus increased over this age range along with a decrease in the bias against responding. The effects of attention were on response bias rather than stimulus sensitivity. These results imply attention affected the localization response to the peripheral stimulus but did not affect the sensitivity of the sensory and perceptual pathways to peripheral stimuli.     

Bilateral disadvantage: lack of interhemispheric cooperation in schizophrenia

Language anomalies and left-hemisphere dysfunction are commonly reported in schizophrenia. Additional evidence also suggests differences in the integration of information between the hemispheres. Bilateral gain is the increase in accuracy and decrease in latency that occurs when identical information is presented simultaneously to both hemispheres. This study measured bilateral gain in controls (n=20) and individuals with schizophrenia (n=10) using a lexical-decision task where word or non-word judgements were made to letter strings presented in the left visual field (LVF), right visual field (RVF) or bilaterally (BVF). Language was not abnormally lateralized in the schizophrenia group. Controls exhibited the expected decrease in latency when words were presented bilaterally. This effect was not observed in the schizophrenia group who were actually disadvantaged in this condition. The lack of bilateral gain in schizophrenia is discussed as arising from differences in the connections between areas in each hemisphere that mediate language.     

Accuracy of movement speed and error detection skills in adolescents with cerebral palsy.

People with cerebral palsy (CP) usually have decreased ability to learn new movements and decreased movement speed. This study examined the ability of 10 adolescents with CP (M age = 16.2 yr., SD = 1.9 yr.) to achieve a target speed on an tipper extremity ballistic task and to detect speed errors in their movements, compared to the performance of 10 adolescents with no disability (M age = 15.7 yr., SD = 1.7 yr.). Subjects were instructed to slide a lever along a track in 150 msec., then guess their movement time. Knowledge of results feedback was provided on the first 50 trials except for Trials 11-20 on Day 1. Knowledge of results feedback was withheld on Day 2, Trials 51-60, to assess learning and retention of the skill. Speed Error and Error Detection were compared for two groups of adolescents on Trials 51-60. Independent t tests indicated a significant difference between the two groups for both Speed Error and Error Detection. Examination of individual scores of the adolescents with CP indicated that half scored within the range of the control group, and variability of skills within the group with CP was high. Some individuals with CP have deficits in accuracy of movement speed and error detection unrelated to their severity of CP which may affect their ability to learn new movements.     

Attention in athletes of high and low experience engaged in different open skill sports

In this study were examined differences in attentional style of athletes engaged in two open skill sports requiring high reactivity (karate and volleyball) in groups with high or low experience. 42 healthy men, 24 volleyball players, 12 of High Experience (first division Italian League players whose M age was 28 yr. (SD=5) and 12 of Low Experience (prejunior Italian team athletes whose M age was 19 yr. (SD= 2). and 18 karateka, 9 of High Experience (3rd and 4th dan black belt athletes whose M age was 31 yr., SD=5) and 9 of Low Experience (1st and 2nd dan black belt karateka whose M age was 32 yr., SD=5). Tests involved different types of attention: Alert, Go/No-Go, Divided Attention, and Working Memory. For each one, the reaction time (RT), variability, change in RT, and number of errors were analysed. Karateka of High Experience reacted faster than those of Low Experience on the simple RT test, Alert (M RT: 204 vs 237 msec., p< .01), while on the Divided Attention test, the High Experience subjects performed more poorly and committed more errors (M errors: 4.89 vs 1.44, p <.003). Young volleyball players of Low Experience reacted faster than colleagues of High Experience on the Alert (M RT: 187 vs 210 msec., p<.01) and Divided Attention tests (M RT: 590 vs 688 msec., p<.001) but committed more errors (Divided Attention test, M errors: 6.50 vs 3.08, p<.007). For the Divided Attention and Working Memory tests, correlations were positive among errors, RT, and RT variability but only for volleyball athletes of High Experience, suggesting they showed higher attention and stability in complex reactions than the group with Low Experience. No significant correlations were noted for either group of karateka on complex reactions. Results suggested that the attentional resources were engaged in different ways in the two groups of athletes and, in each group, there were differences between persons of High and Low Experience.     

Tactile stimulation and interhemispheric communication by learning disabled children: an exploratory study

33 right-handed, learning disabled children aged 8-10 yr., 11-13 yr., and 14-16 yr. were presented a tactile discrimination task. Pairs of fabrics of different or the same texture were presented to the same hand (uncrossed condition) or alternating hands (crossed condition). Analysis indicated that the total number of crossed errors was significantly greater for the youngest children. There were no significant differences between the groups for the uncrossed condition. These results suggest that younger learning disabled children may experience greater difficulty on a task which required interhemispheric transfer.     

Perception of weight-bearing distribution during sit-to-stand task in healthy young and elderly individuals

The first objective was to assess whether healthy individuals could accurately estimate their weight-bearing distribution in sit-to-stand transfers. The second was to evaluate the effect of age on weight-bearing perception. 16 young participants (11 women, 5 men; M age 29 yr., SD = 8.7) and 15 elderly participants (7 women, 8 men; M age 65 yr., SD = 3.8) were recruited. Verbal instructions and visual feedback referring to different percentages of weight-bearing distribution to execute were used to quantify weight-bearing perception in sit-to-stand tasks. For the feedback approach, the perception was assessed with a visual analog scale. For the verbal task, the weight-bearing distribution produced was assessed with force plates. Both young and elderly participants had good perception of weight-bearing distribution, with mean absolute errors of 6.4%. Moreover, their perceived and real weight-bearing distribution showed good agreement (ICC > or = .79).     

Effects of attention state on electrodermal activity during auditory stimulation of children.

During passive and active listening tasks electrodermal activity of 49 healthy school children was studied. The procedure included baseline recording, a passive listening task, instructions, and simple and discriminative active-listening tasks. On the passive task from Trials 1 to 10, habituation of the amplitude of the skin conductance response (SCR) occurred. Habituation of SCR amplitude did not occur during the active tasks. The children seemed to pay more attention during the active tasks than during the passive task, since the need to press the key is apt to require and may even increase general attention. As for temporal variables of SCR, the frequency of spontaneous SCRs showed a significant negative correlation with SCR latency and rise time. Reaction time exhibited a significant negative correlation with age. An increase in reaction time was found during the discriminative active-listening task over that for the simple active-listening task during the course of 10 trials. The younger children (6-8 yr.) seemed to require longer to pay attention than the older ones (10-12 yr.). Children seemed to pay more attention during the discriminative than during the simple active-listening task, since the need to press the key for discrimination should require and is likely to increase general attention.     

Control processes in typing

Recent studies have used errors in speech and typing as a source of evidence for the hypothesis put forward by Lashley (1951) that response is hierarchically organized. The present study continues this line of inquiry on typing, using both the form of the error and its latency as data. Earlier models to account for the latency of typing have postulated two stages of output processing and with a slight modification to the notion of a stage it is shown that they can also account for the error data. Suggestions are made on the nature of codes represented in each stage and on the aetiology of errors. An analysis of response latency in the vicinity of errors supports a conclusion that error detection is very rapid and the (inferred) incidence of detection suggests that it is based upon a comparison process rather than an estimate of response likelihood.     

Relationship of left-right reversals to academic achievement

The study was designed to investigate the relationship of reversal of letters and numbers to academic achievement to decide if the tendency to reversal might be used to predict achievement. Two groups of 45 predominantly white third-grade students whose chronological ages were 9.0 yr. or above were administered the California Achievement Tests and the Jordan Left-Right Reversal Test. A statistical comparison was made using scaled scores on the California Achievement Tests and raw errors on the Jordan Left-Right Reversal Test. Reversal was significantly correlated with academic achievement. Children who exhibit reversals at 9 yr. of age or older may be expected to perform less well academically than children who do not reverse letters.     

Oral and visual presentation and production of original responses.

Verbal originality scores were obtained from Onomatopoeia and Images, Form 1B, given to 106 Ss aged 10 to 12 yr. and 94 Ss aged 16 to 19 yr. The older Ss scored significantly higher than the younger Ss with significant main effects for age, but not for method of word presentation. A significant interaction was found between word presentation method and age. Older Ss were more original with the oral presentation while the younger Ss performed approximately the same with both methods.     

A longitudinal investigation of visual event-related potentials in the first year of life

The goal of the current study was to assess general maturational changes in the ERP in the same sample of infants from 4 to 12 months of age. All participants were tested in two experimental manipulations at each age: a test of facial recognition and one of object recognition. Two sets of analyses were undertaken. First, growth curve modeling with mixed models was used to examine trajectories of development and possible differences in trajectories based on recognition memory (novel versus familiar) and/or stimulus-specific memory (face versus object recognition). Our results suggest that the Pb, Nc and Slow Wave components change significantly in terms of amplitude and latency over the first year of life. Pb amplitude showed a significant non-linear increase over time, whereas Pb latency showed a significant linear decrease over time with a plateau beginning at 10 months. Nc amplitude showed a significant linear decrease over time (i.e. a stronger negative value), whereas Nc latency showed a significant linear decrease over time, with a plateau beginning at 8 months. Second, to relate our findings to those reported in the literature, we examined the effects of memory and stimulus and their combination. Differences between recognition memory and stimulus specific memory were found in the responses to familiar and novel faces and objects for all three components, although the pattern differed across the five ages. These results have implications for future studies that involve the recording of the visual ERP, and point to the advantages of growth curve modeling in examining longitudinal data to account for non-linear development.     

Transfer of training for two ball-throwing tasks

The effects of training overhand ball throws to enhance underhand ball-throwing accuracy were studied with 921 Italian high school pupils (575 girls, M age = 16.5 yr., SD = 1.3; 346 boys, M = 16.5 yr., SD = 1.2) ages 14 to 18 years. A standardized test (10 underhand tennis-ball throws into the floor area delimited by an 80-cm radius wooden hoop lying on the floor 9 m from the standing pupil) was performed and scored. An Experimental group (435 girls, M age = 16.5 yr., SD = 1.3; 204 boys, M age = 16.5 yr., SD = 1.2) was randomly selected to participate in 10 weekly training periods. The set included 10 overhand throws of a rubber bouncing ball (14.5 cm diameter, weight 240 g) into a basketball hoop from 5 standardized positions (in front of the basketball hoop; at 45 degrees, 90 degrees on the right and on the left of the basketball hoop) at a distance of 4.40 m. The underhand test was repeated for both groups. On the average, boys obtained higher test scores than girls of the same age. Older adolescents had higher mean scores than younger adolescents. After 10 weeks, boys and girls of all ages improved. Mean differences between sessions were significant for the Experimental group (Student t test, p < .01). In Session 2, consistent differences between Experimental and Control groups were also found (Student t test, p < .05).     

Scotopic sensitivity/Irlen syndrome and the use of coloured filters: a long-term placebo-controlled study of reading strategies using analysis of miscue

This study investigated the long-term effects of using coloured filters on the frequency and type of errors in oral reading. A double-masked, placebo-controlled crossover experimental design was used, with subjects being assessed over a period of 20 months. There were three experimental groups (Placebo tints, Blue tints, and Diagnosed tints) involving 113 subjects with reading difficulties, ranging in age from 9.2 yr. to 13.1 yr. The 35 controls (ranging in age from 9.4 yr. to 12.9 yr.) had reading difficulties but did not require coloured filters. There was a significant improvement for all groups in the accuracy of miscues over the period, although experimental groups over-all did not improve at a significantly different rate than the control group. The failure to find significantly greater improvement for the experimental groups over the control group for the total period, despite subjects' reports of improved print clarity, may be partly related to the lack of effective letter-sound analysis and synthesis skills and to the use of a word-identification strategy of guessing based on partial visual analysis.     

Cognitive tempo in children and their parents.

An adoption study was conducted to determine if cognitive tempo (as characterized by errors and latencies on the Matching Familiar Figures Test) is more similar between parents and their biological children or between parents and their adopted children. Zero-order correlations between parents and children were not significant (regardless of familial relationship), but the results of canonical correlations for mean of parents' scores with those of biological and adopted children respectively were consonant with hypothesized values, suggesting a degree of heritability exists. A slight trend for parents' latency to be consistently related to their biological children's latency was noted, but no such trend was present for errors. The heritability of latency versus errors in cognitive tempo is discussed.