Developmental differences in motor task integration: A test of Pascual-Leone's Theory of Constructive Operators

This study assessed the ability of Pascual-Leone's Theory of Constructive Operators to predict the minimum age or maturational level at which integration of a motor task could be achieved. Children 5–12 years of age (n=114) performed a discrete motor task requiring a constrained circular movement to be integrated with an unconstrained linear movement to a target. The Theory of Constructive Operators and the principles of constructive cognition were used to generate a model of task performance. Based on the model and in accordance with the theory, it was predicted that 5- to 6-year-old subjects would lack the cognitive capacity (M-capacity) to efficiently integrate this task. An analysis of covariance for age was performed on task parameters reflecting integration (and highest M-demand) with movement speed as the covariate. Scheffé contrasts supported the prediction as 5- to 6-year-old subjects were inferior to each of the other age groups (p < .05). Furthermore, no significant differences were found to exist between any of the older age groups.     

Individualized learning environments: Intra- and interpersonal consequences

This study examines the effects of individual goal structures on the intra- and interpersonal behavior of 120 fourth-grade children. Each group of four children was introduced to one of two individualized learning programs: (a) workbook materials color-coded according to level of difficulty (allowing implicit comparisons among children as to progress), and (b) materials not coded according to difficulty (discouraging comparisons). In both learning programs, children worked individually (at story writing) and were rewarded for the work. Results indicate that boys, but not girls, who were rewarded equally for doing good work in an individualized setting but who start and end at a lower step than other more frequently took away a toy from those peers with whom they compared themselves than did boys who were rewarded equally for good work and where there were no comparisons. Boys as a group, regardles of condition, gave more prize tickets to themselves than to others and gave more prize tickets to themselves than girls gave either to themselves or others. Both boys and girls appear to adopt the evaluations of their work given by the experimenter and appear to be influenced thereby in later prized-giving to themselves and to others.     

Resolution time and the coding of arithmetic relations on supraliminally different visual extents

Comparison time for pairs of vertical-line stimuli, sufficiently different that they can be errorlessly discriminated with respect to visual extent, was examined as a function of arithmetic relations (physical ratio and difference) on members of the pair. Arithmetic relations are coded very precisely by judgment time: Responses slow as stimulus ratios approach one with difference fixed, and as stimulus differences approach zero with ratio fixed. Most models which assume a simple (Difference or Ratio) resolution rule operating on independent sensations require judgment time to depend on either ratios or on differences but not on both. Further tests showed both an index based on median judgment times and a confusion index based on pairs of observed judgment times, satisfied the requirements for a Positive Difference Structure. One representation of these data, which remains acceptable through all analyses, is a Difference resolution rule operating on sensations determined by a power psychophysical function with β < 1. Specifically, L(x, y) = F{ψ(x) ? ψ(y)} + R, where L(x, y) is the judgment time with the stimulus pair x and y, ψ(x) = Ax^β + C, R is a positive constant, and F is a continuous monotone decreasing function.     

Transformations,basic operations and language acquisition

Errors in child speech show that some children initially formulate tense-hopping and subject-auxiliary inversion as copying without deletion. Other errors suggest that some children may formulate other movement rules as deletion without copying. A claim about the nature of the language acquisition device is made on the basis of our analysis of these errors: the language acquisition device formulates hypotheses about transformations in terms of basic operations. The basic-operations hypothesis predicts that for any transformation which is composed of more than one basic operation, there exists a class of errors in child speech correctly analyzed as failure to apply one (or more) of the operations specified in the adult formulation of the rule.     

Developmental differences in remembering sentences after integrative or selective semantic processing

Fifth graders (age: 10 years) and college undergraduates performed one of four different semantic orienting activities on a series of agent-action-object sentences. Afterwards all subjects received a memory test combining recognition for whole sentences with cued recall for component agents, actions, and objects. Overall levels of both recall and recognition varied with the orienting activities. Relative recallability of agents, actions, and objects varied with orienting activity as well. Recognition performance improved with grade level but recall did not. The interaction between type of memory test and grade level was taken to indicate that organization of material in memory increases during adolescence even when the total amount of material stored does not.     

A critical analysis of the attention hypothesis of Zeaman and House: problems of parameter interactions in multiparameter models

The attention hypothesis of Zeaman and House [in N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963] was examined through a systematic, computer-simulation analysis of the parameter interactions found in the One-Look model. The hypothesis states that mental retardates and normals differ in their initial attention habits but not in their learning rates in the context of discrimination learning. The analysis showed that possible differences in the learning rates cannot be ruled out. The result was used to suggest how shift designs can unconfound the effect of the attention habits from the effect of the learning rates and maximize chances of observing possible differences in the learning rates between retarded and normal children.     

Developmental changes in visual scanning of face and nonface patterns by infants

The eye movements of infants, aged 4–5, 7–8, and 10–11 weeks, were recorded while they viewed either a representation of a face or a nonface stimulus. Presentation of the visual stimulus was paired with the presentation of an auditory stimulus (either voice or tone) or silence. Attention to the visual stimulus was greater for the older two groups than for the youngest group. The effect of the addition of sound was to increase attention to the visual stimulus. In general, the face was looked at more than the nonface stimulus. The difference in visual attention between the face and the nonface stimulus did not appear to be based solely on the physical characteristics of the stimuli. A sharp increase in the amount of looking at the eyes of the face stimulus at 7–8 weeks of age seemed to be related to a developing appreciation of the meaning of the face as a pattern.