Analysis of the development of children's spatial reference systems

Four, six, and ten-year-old children were required to copy an object's location and orientation within a two-dimensional spatial layout under two conditions: when both E's standard board and that of the S's were in the same orientation and when they were rotated 180 ° from each other. The failure of the 4-yr-olds to copy location and orientation under both conditions even when space was topographically coded indicates that at this age the child does not conceptualize space within two dimensions. Although the errors of the 4-yr-olds tended to be of a self-reference nature with respect to orientation and location on rotation trials the axes of the self-reference system were not coordinated. Six and 10-yr-old children performed significantly better on both conditions, with the exceptions that the 6-yr-olds continued to preserve some orientations within a self-reference system. When topographical codes were removed and S imagined rotation there were no significant age differences in total errors; however, older children organized entire subspaces within a self-reference system. The findings support Piaget and Inhelder's hypothesis that two-dimensional reference systems do not develop until the period of concrete operational thought, and they also indicate that even at age 10, the self-reference system continues to function when topographical codes are absent. Several cognitive mechanisms proposed to account for the development of spatial abilities are critically discussed.     

Reconstruction from the mental image

In three experiments young children were asked to reconstruct an array of objects after they had imagined its appearance following either a rotation of the array or a change in their own position (Huttenlocher & Presson, 1973). In reconstructing arrays, subjects first positioned that object which would be most prominent to an observer following the imagined transformation. Surprisingly, this occurred even when subjects made an egocentric error by reconstructing a copy of the original array. Hence young children, although apparently egocentric, can imagine themselves in a new position with a new perspective. The mental operations which underlie imagined spatial transformations are discussed in light of the results.     

Male versus female Siamese fighting fish as reinforcing stimuli for conspecific males in single- and two-choice operant situations

Two experiments attempted to determine the reinforcing effectiveness of visual exposure to a female versus a male stimulus in male Siamese fighting fish (Betta splendens). This was accomplished by making male or female presentation contingent upon an operant ring swimming response in single- (Experiment 1) and two-choice (Experiment 2) continuous reinforcement operant situations for 1 hr per day. It was found that visual exposure to a female stimulus was behaviorally reinforcing in a way comparable to that typically found in intermale studies. If given a choice, male test subjects were observed to demonstrate a consistent preference for the female as opposed to the male stimulus. The results are discussed in terms of stimulus discrimination and approach-avoidance conflict as differentially elicited by male and female target stimuli.     

An organizational analysis of the form class effect

The paper reports eight experiments concerning the form class effect. If verb connectives enhance organization between pairs of nouns more than do conjunction connectives, then (a) the form class effect should obtain in cued but not free recall, (b) interactive imagery instructions should raise performance with conjunctions, removing the effect, (c) separation imagery instructions should reduce performance with verbs, removing the effect, and (d) prepositions implying spatial contact should be superior as mediators for cued recall compared with less suggestive prepositions. The results of the experiments confirm the predictions, except that grade 3 children do not perform as expected with the instructional variables.     

The repetition effect in time judgments is not a function of the intensity of the stimulus defining the interval: implications for an arousal theory

College students (N = 17 per group) estimated the durations of time intervals ranging from 8 to 20 sec. Intervals were defined by tones of 35, 55, and 75 db for each of three groups. The estimates of all groups declined across trials, but the degree of decline did not differ as a function of stimulus intensity. These data call into question the view that the repetition effect is attributable to a decrement in general arousal.     

Memory for companions in preschool children

Memory of preschool children (4 years of age) for companions was investigated by comparing interview data using a picture sociometric technique with observational data on actual play companions. Accuracy decreased with successive nominations, and length of recall period. However children were able to name companions played with today, yesterday, last week and at the beginning of term, at well above chance levels. Accuracies improved during the term. The relevance of friendships and social experience for memory and cognitive processes in young children is discussed.     

Are there developmental differences in reality-monitoring?

The question addressed by the present experiment is whether the ability to distinguish between veridical and imaginal memory representations changes with age. Second-grade, fourth-grade, and sixth grade children (8, 10, and 12 years old) and college students were shown pictures of familiar objects. Each picture was presented one, two, or three times and, interspersed with these presentations, subjects were asked to imagine each picture zero, one, or three times. Subsequently they were asked to judge the presentation frequency of each picture. For all groups, imagining the pictures resulted in inflated estimates of event frequency. However, contrary to the idea that children have a particularly difficult time discriminating externally generated from internally generated memories, one analysis indicated adults were actually somewhat more affected than children by the imagination trials.