Developmental changes in the internal structure of semantic categories

The present experiment was designed to examine the development of the cognitive representation of semantic categories. Response latencies on a classification task were compared for second, fourth, and sixth graders (8, 10, and 12 years of age, respectively) and college students. On each trial the subjects were presented with two pictures that represented either typical or atypical category exemplars. The two pictures were physically identical, nonidentical pictures from the same category, or pictures from different categories. One half of the trials were primed by presenting a category name in advance of the stimuli. In addition, stimulus degradation was manipulated in order to assess the locus of priming effects. A significant interaction of age × priming × typicality was found for physically identical stimuli. This interaction indicated that the nature of the internal representation of categories changed from the second graders to the adults. It was suggested that the second graders might weigh features inappropriately in generating semantic prototypes. The fact that stimulus degradation and priming did not interact at any age level for any of the match types indicates that priming affected a conceptual encoding stage rather than a perceptual encoding stage.     

ELIMINATION OF ECHOLALIC RESPONDING TO QUESTIONS THROUGH THE TRAINING OF A GENERALIZED VERBAL RESPONSE

Echolalia, the parroting of the speech of others, is a severe communication disorder frequently associated with childhood schizophrenia and mental retardation. Two echolalic children, one schizophrenic and one retarded, were treated in a multiple-baseline design across subjects. Each child was taught to make an appropriate, nonecholalic verbal response (i.e., “I don't know”) to a small set of previously echoed questions. After such training, this response generalized across a broad set of untrained questions that had formerly been echoed. The results obtained were the same irrespective of the specific experimenter who presented the questions. Further, each child discriminated appropriately between those questions that had previously been echoed and those that had not. Followup probes showed that treatment gains were maintained one month later. The procedure is economical, in that it produces a rapid and widespread cessation of echolalic responding.     

PL 94–142 and Its Impact on the Counselor's Role

The new federal law pertaining to the education of handicapped students requires that all students must be provided with an adequate educational program. Specific procedures and requirements are mandated. The implementation of the law places new demands on the total educational profession and also creates new opportunities to use counseling skills and new avenues for the continued advancement of humane values.     

Linking large and small computers

A PDP-8/I was connected to an IBM/370 via telephone. Programs enable the PDP-8 to send data to practically any large-scale computer having timesharing capabilities. These programs can be used as models by others wishing to analyze data on a large computer.     

The SIMPLE T-scope

The SIMPLE system for a computer-based tachistoscope is reviewed, and features of its structure are described. An example is explained in detail.     

On a neglected variable in theories of pictorial perception: Truncation of the visual field

Theoretical analyses of pictorial perception have concentrated on the consequences of conflicting flatness and depth information in pictures, but have failed to consider the perceptual effects of the truncation of the visual field attendant on any pictorial display. The importance of this variable both for methods of testing pictorial information and for theory building was demonstrated. Under four different viewing conditions, adults were asked to scale the size and distance of five isoceles triangles at five different distances. The four conditions were unobstructed static monocular view, peephole view, view through a rectangular frame, and view of all the stimuli photographed in a slide. The slopes of the peephole, truncation, and slide conditions’ scaling functions were all significantly smaller than the slope of the untruncated Monocular condition, and the Y-intercepts were all greater. A decrease in over-constancy in the size functions indicated a similar effect for all three truncated conditions. Results are interpreted as supporting the hypothesis that truncation of the visual field, both in pictures and in peephole views of the real world, causes a frontal shift in the localization of the visible field, with a resultant compression of perceived size and distance.     

Three experiences affecting spatial discrimination learning by ambulatory children

Children 1 and 3 years of age were given a two-choice spatial discrimination task. They were placed in front of a barrier and encouraged to walk around it; one route around the barrier was blocked. Three experiments studied the effects of different types of experience with this spatial problem. The first examined trial and error experience, in which the child was allowed to walk the route he or she had chosen. Although most children readily learned to choose the open route, the pattern of choices indicated that 3-year-olds were more likely to achieve a learning criterion after an error than 1-year-olds. A second experiment looked at the effects of showing the children the layout of the problem prior to trial and error experience. The 3-year-olds were again more likely than the 1-year-olds to achieve criterion after an error; furthermore, they were likely to know the correct route on the first trial. The third experiment let the children watch their parents take the correct route. This procedure eliminated age differences in performance. The initial choices of the 1-year-olds indicated that they were likely to know the correct route, and if they did not, they were just as likely to learn from their mistakes as the 3-year-olds. The data were interpreted within a mathematical model of learning. Based upon these analyses, we propose two developmental trends. One involves a growth in sensitivity to the consequences of a choice of route. The other is a progression from social learning to more independent and ideational methods of spatial problem solving.     

Neonatal functioning and the sudden infant death syndrome

A male infant, diagnosed as a Sudden Infant Death Syndrome (SIDS) at 5 months, 3 weeks, had been extensively tested as a part of a larger sample in a longitudinal study. The longitudinal sample was comprised of 137 clinically normal neonates, born to intact upper middle-class families, living in a large metropolitan area. A neonatal assessment consisted of 5 hours of polygraphic recordings of heart and respiratory rate during sleep and waking cycles, and 1 hour of behavioral testing. At 3 months of age the infant was observed for 12 hours in the home. Retrospective analyses of these data suggested that: (a) neonatal respiratory behavior during sleep did not distinguish this infant from a sample of control infants; (b) the infant lacked strength in movements requiring the involvement of shoulder and neck muscles (head lift from a prone position); and (c) informal observations by skilled and experienced observers distinguished this infant from the sample of controls.