Conservation training in four-year-old children

In Experiment 1 two training procedures were used to teach four-year-olds to conserve. Verbal rule instruction consisted of providing verbal rules and demonstrations of the operations referred to by the rules. Feedback consisted of providing verbal feedback contingent upon the children's responses. One week after training on conservation of number and length the children were given a posttest which included tests of conservation of number, length, and mass. Children who were given verbal rule instruction conserved significantly more on the number and length posttest problems than children who were not. However, this learning did not transfer to the mass problems, possibly because mass is not naturally acquired until some time after conservation of number and length. The feedback training procedure had no effect on conservation performance. In Experiment 2, the verbal rule instruction procedure was used to train four-year-olds on conservation of length and mass. One week after training the children were tested on both conservation of number, which is typically acquired before length and mass, and conservation of weight, which is typically acquired after length and mass, as well as on conservation of length and mass. Children who were given training conserved more on all four types of problems than children in the control group.     

The effects of induced affective states on letter discrimination in disadvantaged preschool children

The relationship between affective state and academic performance was examined using 30 4- to 6- year old economically disadvantaged black children. Children were assigned to one of three affective induction groups: positive, negative, or neutral affect. Changes from pre- to posttest administrations of a letter discrimination task suggest that negative and positive affect inductions produce different changes in both errors and response latency. These findings suggest that further research on the possibility that negative affect may be responsible in part for the academic difficulties of disadvantaged children and other children under stress is warranted.     

Effective learning and retention of braille letter tactile discrimination skills in children with developmental dyslexia

Children with developmental dyslexia (DD) may differ from typical readers in aspects other than reading. The notion of a general deficit in the ability to acquire and retain procedural (‘how to’) knowledge as long‐term procedural memory has been proposed. Here, we compared the ability of elementary school children, with and without reading difficulties (DD, typical readers), to improve their tactile discrimination with practice and tested the children's ability to retain the gains. Forty 10–11‐year‐olds practiced the tactile discrimination of four braille letters, presented as pairs, while blindfolded. In a trial, participants were asked to report whether the target stimuli were identical or different from each other. The structured training session consisted of six blocks of 16 trials each. Performance was re‐tested at 24 hours and two weeks post‐training. Both groups improved in speed and in accuracy. In session 1, children with DD started as significantly less accurate and were slower than the typical readers but showed rapid learning and successfully closed the gap. Only two children with DD failed to benefit from training and were not included in subsequent data analyses. At 24 hours post‐training both groups showed effective retention of the gains in speed and accuracy. Importantly, children with DD were able to retain the gains in speed and accuracy, over a two‐week interval as effectively as typical readers. Thus, children with DD were as effective in the acquisition and retention of tactile discrimination of braille letters as typical readers of the same age. The results do not support the notion of a general procedural learning disability in DD.     

Gender comparisons in the perception of self-competence among four-year-old children

The purpose of this study was to determine the presence of gender differences in the perception of self-competence among 4-year-old children. Sixty-one-4-year-olds (27 girls and 34 boys) from predominantly European American backgrounds participated in the study. The children's self-competence was measured using the Pictorial Scale of Perceived Competence and Social Acceptance for Young Children (Preschool version; S. Harter & R. Pike, 1984), which has 4 separate subscales: (a) cognitive competence, (b) physical competence, (c) peer acceptance, and (d) maternal acceptance. A within-subject 2-way analysis of variance with repeated measures of 4 (subscales of perception of self-competence) x 2 (gender) was performed to determine if gender differences existed in the children's perception of self-competence. Analyses of the data showed no significant gender differences in the scores on the 4 subscales for the perception of self-competence among the children. These results could be interpreted as being due to a less gender-stereotyped society and androgynous environment for these preschoolers.     

Mental time travel for self and other in three- and four-year-old children

Humans possess the unique ability to mentally travel backward in time to re-experience past events (i.e., episodic memory) and forward in time to pre-experience future events (i.e., episodic foresight). Although originally viewed as different cognitive skills, they are now both viewed as components of the episodic memory system. Recently, it has been suggested that the episodic system may allow us to not only pre-experience and predict our own future but also that of another person. In the current study, we investigate this possibility by examining the ability of three- and four-year-old children to plan for their own future and for that of another person. We found that both three- and four-year-old children performed equally, when planning for their own future or when planning for the experimenter's future. These data are consistent with the finding that planning for someone else's future recruits the same neural structures that are used when planning for one's own future.     

Numerosity discrimination in preschool children

We used a numerical bisection procedure to examine preschool children's sensitivity to the numerical attributes of stimuli. In Experiment 1 children performed two tasks. In the Cups Task they earned coins for choosing a green cup after two drumbeats and a blue cup after eight drumbeats. In the Gloves Task they earned coins for raising a red glove on their left hand after two drumbeats and a yellow glove on their right hand after eight drumbeats. Then in each task a psychometric function was obtained by presenting intermediate numerosities and recording the percentage of trials in which children chose the "many" option. In Experiment 2 children's performance in a '2 vs. 8' discrimination was compared with their performance in a "4 vs. 16" discrimination. Results showed that the individual psychometric functions were of two types, one in which the percentage of "many" choices increased gradually with stimulus numerosity and another in which it increased abruptly, in a step-like manner. Although the average point of subjective equality was close to the geometric mean of the anchor numerosities and the average functions for "2 vs. 8" and "4 vs. 16" superimposed when plotted on a common scale (the scalar property), the individual data were highly variable both across tasks (Cups and Gloves) and numerosity ranges ('2 vs. 8' and '4 vs. 16'). It is suggested that between- and within-subjects variability in the psychometric function is related to children's verbalizations about the sample stimulus.     

A diffusion model analysis of the effects of aging on letter discrimination

The effects of aging on accuracy and response time were examined in a letter discrimination experiment with young and older subjects. Results showed that older subjects (ages 60-75) were generally slower and less accurate than young subjects. R. Ratcliff's (1978) diffusion model was fit to the data, and it provided a good account of response times, their distributions, and response accuracy. The results produce similar age effects on the nondecision components of response time (about 50 ms slowing) and the response criteria (more conservative settings) to those from R. Ratcliff, A. Thapar, and G. McKoon (2001), but also show a reduced rate of accumulation of evidence for older subjects. The model-based approach has the advantage of allowing the separation of aging effects on different components of processing.     

Fading procedures and conditional discrimination in children

A discrimination reversal task followed by a conditional discrimination problem was administered to children (age range 36 to 107 months). A fading procedure was used during the discrimination reversal training of some subjects and other subjects were trained by a traditional procedure. More subjects trained by the fading procedure performed without errors during training and more subjects in the traditional group solved the conditional discrimination problem.     

An analysis of emergent simple discrimination in children

In Experiment 1 eight five-year-old children received an arbitrary matching-to-sample task with sample stimuli A1 and A2 and comparison stimuli B1 and B2. This task was mixed with a simple, two-choice discrimination task with stimuli A1 and A2. In subsequent tests with B1 and B2 presented alone, the number of responses to B1 was greater when it had been paired with the correct stimulus of the simple discrimination task than when it had been paired with the incorrect stimulus. In Experiment 2 incorrect comparisons were omitted during the matching-to-sample task. Eight children were taught to point to either A1 or A2 first, and to either B1 or B2 second. Eight other children were taught to point to either B1 or B2 first, and to either A1 or A2 second. The effect of Experiment 1 was replicated with the first but not with the second group. The results of both experiments suggest that the functions of S+ and S- in a simple discrimination task can transfer to test stimuli if the training stimuli precede the test stimuli during paired presentations.