Parents' teaching strategies with their children: The effects of parental and child status variables

The intent of the study was to examine the effects of parental (mother and father) and child (gender and communicative status) status variables on the teaching strategies used by parents in a paper-folding task. The linguistic and nonverbal strategies of 120 parent-child groupings were analyzed during paper-folding tasks. Parents' strategies were coded according cognitive demand and directiveness. Results indicated that strategies varied as a function of children's communicative status. Parents were less directive and more demanding of nonhandicapped children compared to handicapped children. Parents' strategies seemed to be determined by children's ability to sustain discourse. Results are discussed in terms of Vygotsky's notion of the zone of proximal development.This research was partially supported by a grant from the U.S. Office of Education, Office of Special Education (Grant No. G007902000) to I. Sigel and A. McGillicuddy-DeLisi at Educational Testing Service, Princeton, and from the Biomedical Research Support Grant Program, Division of Research Resources, N.I.H. (Grant No. BRSG 507RR07025-17) to the first two authors. We acknowledge the helpful comments of two anonymous reviewers.     

Smoking,personality, and imagery preference in Relation to spontaneous bilateral electrodermal activity

Effects of smoking on spontaneous bilateral skin conductance were studied as a consequence of interactions with set and setting. Bilateral skin conductance was recorded in six men and six women who smoked and an equal number of nonsmokers on two different days. On the first day, spontaneous electrodermal activity was recorded before and after a 10-minute rest period during which half the smokers smoked a cigarette. On the second day, one week later, spontaneous activity was again recorded before and after a 10-minute rest period during which the remaining smokers smoked a cigarette. Nonsmokers did not smoke at any time. Following smoking there was a significant negative correlation between a preference for visual over nonvisual imagery and spontaneous skin conductance responsivity in the left as compared to the right hand. Correlations were significantly different in smokers and nonsmokers. Smokers showed significantly greater preferences for either visual or nonvisual imagery than nonsmokers. Nonresponding nonsmokers were higher on the psychoticism (P) scale of the Eysenck Personality Questionnaire (EPQ) than responding nonsmokers. Smokers scored higher on P than nonsmokers. Interactions between personality, cognitive style, and the experimental situation, set, and setting were discussed in relation to the arousing effects of nicotine.     

Observational learning of two visual discriminations by pigeons: a within-subjects design.

Pigeon's observational learning of successive visual discrimination was studied using within-subject comparisons of data from three experimental conditions. Two pairs of discriminative stimuli were used; each bird was exposed to two of the three experimental conditions, with different pairs of stimuli used in a given bird's two conditions. In one condition, observers were exposed to visual discriminative stimuli only. In a second condition, subjects were exposed to a randomly alternating sequence of two stimuli where the one that would subsequently be used as S+ was paired with the operation of the grain magazine. In a third experimental condition, subjects were exposed to the performance of a conspecific in the operant discrimination procedure. After exposures to conspecific performances, there was facilitation of discriminative learning, relative to that which followed exposures to stimulus and reinforcement sequences or exposures to stimulus sequences alone. Exposure to stimulus and food-delivery sequences enhanced performance relative to exposure to stimulus sequences alone. The differential effects of these three types of exposure were not attributable to order effects or to task difficulty; rather, they clearly were due to the type of exposure.     

A new challenge to ethical codes: Heart transplants

Summary We have entered into a new era of medical achievement with the development of successful transplantation of human organs. The transplantation of the heart has aroused the greatest scientific interest and at the same time created serious new problems of an ethical and legal nature. It has been necessary to develop new criteria to determine the moment of death of the donor in order to ensure continued life for the recipient. The decision of the moment of death should be made by a small team of skilled physicians interested in furthering this important development, but not as emotionally involved as are the surgeons awaiting the chance to prolong their patient's life with a new heart. Available and suitable hearts will probably always be in very short supply, and the selection of recipients will therefore become critical if the procedure proves to be widely acceptable.New laws will be essential before this process can be adopted in many states and countries. The cost in terms of total resources is so large that careful evaluation of the long-term results must be undertaken after a reasonable number of patients have been operated on and observed, perhaps at the end of the second year following the first procedure. Since the cost of each operation of this type approximates that of the education of several young physicians who could care for thousands of patients during their life span, a good hard look at the potential benefits and ultimate values is in order. At this point in time it is extremely important that this type of surgery be encouraged but limited to those prepared to undertake it with maximum skill and minimal risk. At present it must be recognized as a great experiment rather than a therapeutic triumph for general application.     

The role of the cs and avoidance period duration in discriminated avoidance conditioning

In an experiment investigating the effect of CS duration on discriminated bar-press conditioning, subjects were assigned to one warning period duration (1.5, 5.0 or 15.0 sec.) on the first day of avoidance training, and to one of the three durations on the second day of training. On each day avoidance behaviour was greatly influenced by the duration of the CS (warning) period, but the duration on day I had no effect on the second day's avoidance performance. Groups receiving no CS during training, although provided an avoidance contingency, showed little conditioning, but produced highly significant amounts of intertrial responding. In a second experiment, subjects receiving CS on day I were shifted to no CS on day II. Avoidance performance on day II was not significantly different from the day II performance of subjects in Experiment I having two training sessions with the CS present or absent on both days.     

PIGEONS ARE SENSITIVE TO THE SPATIAL ORGANIZATION OF COMPLEX VISUAL STIMULI

Abstract— Two experiments investigated the role of spatial organisation in the discrimination and generalization of complex visual stimuli by pigeons. In Experiment 1, after pigeons had been trained to discriminate line drawings of four objects, they were tested with novel pictures in which the same component parts of the objects were spatially rearranged. The spatially scrambled pictures led to a dramatic drop in recognition accuracy, hut responding remained above chance. In Experiment 2, pigeons reached a high level of discriminative performance when required to choose among four different spatial arrangements of the same object parts. These results confirm Cerella's (1980) conclusion that pigeons discriminate the component parts of complex visual stimuli, but. unless it is assumed that the scrambling deleted or created emergent features, the results disconfirm his conclusion that spatial organization plays no role in pigeons' picture perception.