Object disappearance and error in Piaget's Stage IV task

Piaget attributes perseverative error in infant manual search to the failure of the infant to conceive of objects as permanent entities which retain their identity when hidden at successive locations A and B. An experiment was performed to test this explanation in which search was compared under three conditions: when the object was hidden at A and B, when the object was covered but visible at A and B, and when the object was visible and uncovered at A and B. Errors occurred under all three conditions taking the form of a conflict in which infants searched persistently either at A or at B. The conflict was at a maximum when the object was hidden, but was evident even when the object was visible but covered. It is suggested that errors may reflect lack of coordination between egocentric and visual frames of reference in relation to which the object is located.     

The effects of attention-directing training on recognition memory task performance of three-year-old children

Thirty-eight 3-year-old children served as subjects in an investigation of recognition memory in which schematic faces differing only in the orientation of the eyes were employed as stimuli. A pretest was administered to all children, after which the two experimental groups received training in either attention to the distinctive feature of the training stimuli (also schematic faces) by means of a matching task, or in labeling the faces according to how they looked (sleepy, happy, sad, mad) and in using the labels to perform a matching task. After the training session all children were given a posttest on recognition memory of the faces. The verbally trained group obtained significantly higher scores on the posttest than either the feature or control groups. These results indicate that although the children were able to discriminate the faces, evidenced in their ease of performance on the training tasks, they were not able to use this knowledge unless given training in attaching labels to the stimuli, which enabled them to store the information for later use. Results are discussed in light of Gibson's (1969) theory of the developmental interrelations of cognitive processes.     

Modification of cooperation and aggression through teacher attention to children's speech

Two experiments were performed in the naturalistic setting of a preschool classroom in order to assess the effects on children's social behavior of nonevaluative teacher attention to children's cooperative or aggressive speech. In Experiment 1, teachers attended to the children's spontaneous cooperative speech for two weeks. Observation of the children's free-play behaviors revealed an increase over baseline levels in both verbal and physical cooperative behaviors as well as a decrease in both verbal and physical aggressive behaviors. In Experiment 2, teachers attended first to the children's spontaneous aggressive speech for one week and then switched their attention to the children's cooperative speech for a second week. Teacher attention to aggressive speech in the first week led to an increase over baseline levels in the children's verbal aggressive behavior as well as a decrease in both verbal and physical cooperative behaviors; however, physical aggression remained unchanged. Teacher attention to cooperative speech in the following week served to reverse the effects of the first week's treatment. The findings were discussed in terms of the sequential relationship between verbal and nonverbal components of cooperative and aggressive social behaviors and the teacher's role in modifying children's performance on these behaviors in the classroom.     

Development of binocular fixation in human infants

Two experiments measured changes in binocular eye alignment from 1- to 6-month-old human infants. In Experiment 1 changes in binocular eye alignment were recorded from 1, 2, and 3 month olds using corneal photography. A luminous target was moved along the infant's midline at one of two constant speeds. Infants at all three ages showed some evidence of appropriate changes in binocular eye alignment (convergence as the target approached and divergence as the target receded). The likelihood of appropriate convergence and divergence increased with age, as did the ability to respond appropriately to the faster target motion. A measure of convergence lag (further decrease in interpupillary distance after target motion had ended) was obtained for trials on which the target approached the infant. Convergence lag decreased with age and was greater on trials at the faster target speed until 3 months of age. Experiment 2 measured the responses of 3, $\text{4}\text{1}\text{2}$, and 6 month olds as a wedge prism was placed alternately in front of each eye. The prism displaced the image nasally (either 2.5° or 5°), creating inappropriate binocular eye alignment. A refixation eye movement in response to the prism was not present consistently until 6 months of age. Hypotheses as to the mechanism controlling infant binocular eye alignment are discussed with respect both to the present findings and to findings from human adults and animals.     

Differences in the search rate of children and adults in short-term memory

When people recognize a test item as belonging or not belonging to a previously presented set, recognition latency increases with the number of items in the set. Although some evidence suggests otherwise, it is currently held that the rate of this increase is the same for children and adults. In contrast, the present experiments indicated a much slower search rate for second graders (mean age = 7.33 years) than for seventh (mean age = 12.50 years) and twelfth graders (mean age = 17.25 years). Moreover, search rate for second graders was invariant under instructions which did or did not emphasize speed and with presentation of the memory set in either the auditory or visual modality. Experiment II showed that the slow search rate for children was not due to differences in encoding between children and adults.     

Visual-feature and response components in a picture-word interference task with beginning and skilled readers

A series of four experiments is reported in which reaction times for naming line drawings were analyzed as a function of the similarity of the print superimposed on the drawings to the printed label for the drawing. This effect was studied as a function of grade level (ages 6, 8, and 11 years) and, hence, reading experience. The studies were designed to determine more precisely the characteristics of the stage of visual feature analysis of word identification and to examine response competition factors in this interference task. Results indicated that a combination of end letters and word shape was important for word identification and that response articulation was a significant distinct interference component in this task.     

Introtacts as predictors of discrimination performance in kindergarten children

Kindergarten children were given simultaneous discrimination tasks with two irrelevant dimensions varying within settings. Prior to each block of eight feed-back trials, the children were asked to attempt to provide a statement of the solution. The introtacts thus provided were found to have several of the desirable characteristics that have been reported for older children with either introtact or blank-trial probes, but which have not been found previously for kindergarten children with the blank-trial probe. Classification of the children according to the trial block on which they first verbalized the correct relevant dimension was found to account for more than 60% of the total variability in discrimination performance. The introtacts were also used to assign parameters to theoretical prediction equations, with nearly two-thirds of the total variability in discrimination performance accounted for by the theory. Extension of the method to other models is discussed.     

Effects of differential reinforcement and task difficulty on preschoolers' compliance with teacher instructions

Preschool children in day schools were given instructions to complete certain tasks. Four tasks were given of two types and two levels of difficulty. In each condition compliance with at most one instruction (one task) was reinforced. In two similar experiments, with six children, general results were: compliance with easy tasks was maintained without reinforcement when any task compliance was reinforced; compliance for hard tasks remained high only when that specific task was reinforced. Thus, generalization of compliance with instructions varied with task difficulty. The setting and procedure for both studies were designed to reduce possible coercive features of laboratory studies of generalized performance. Results show generalized performance can occur under naturalistic conditions. The effect of effort, as a response characteristic affecting generalized performance, is discussed.     

Children's strategies in producing three-dimensional relationships on a two-dimensional surface

It is a common task to give children a picture containing implicit depth cues and to require them to extract depth information from it. The cues are always selected from the adult repertoire; little is known about children's production of their own cues. In this experiment, 5- to 10-year-old children were required to draw one object behind another in a situation in which adults invariably produce the further object partially occluded by the nearer. The results were an age-related decline in the tendency to segregate the objects and an increase in the tendency to group the objects using partial occlusion, with a cross-over at 8 years. At all ages some children drew one object inside the boundary of the other. It is argued that the results are composed of two tendencies, a gradual mastery of discrete scaling phenomena (e.g., “up” on the page means “further”) within a given style, and a set of decisions to be made between incompatible styles.