Positive behavioral contrast when pigeons press treadles during multiple schedules

Pigeons were placed on multiple variable-interval 15-second variable-interval 15-second and on multiple variable-interval 15-second extinction schedules in which treadle presses produced food reinforcers. Positive behavioral contrast occurred. That is, rates of responding were higher during the variable-interval 15-second component when the other component was extinction than when it was another variable-interval 15-second schedule. These results contradict the findings of other studies, which failed to find positive contrast when pigeons pressed treadles for food reinforcers. They may also question the additive theories of behavioral contrast that predict that contrast should not occur in this situation.     

Children's perceptions of major positive and negative events and factors in single-parent families

A study was designed to tap children's perceptions of the divorce situation as opposed to adults' perceptions of the child's response to the parental divorce. Subjects were 75 boys and 75 girls from mother- and father-headed families. Using an individual structured interview procedure children were encouraged to reconstruct both positive and negative dimensions of their interactions with the custodial parent. Through factor analyses of the contents of interviews four negative and two positive factors involving 20 specific items were identified in the children's perceptual data. Subsequently, chi-square analyses were done to compare differences in girls' and boys' perceptions between and across father- and mother-headed families. Results are discussed in terms of their relationship with the existing literature and their clinical and educational relevance to children, single parents and professionals.     

Bilingualism and brain functional asymmetry

The task of the neural organization of the native language, acquired by a direct method and of another language, studied at school, performed correspondingly by the left and the right hemispheres, was studied in the bilingual patient after unilateral electroconvulsive therapy used in psychiatry. It was established that in such a bilingual type the right hemisphere is concerned with the formation of deep semantic structures of the native language while the left hemisphere is responsible for the formation of second language deep structures and of surface structures of both languages. The effect of language learning method on cerebral organization of bilingualism is postulated.     

SOME EFFECTS OF REINFORCEMENT SCHEDULES IN TEACHING PICTURE NAMES TO RETARDED CHILDREN1

The effects of several different schedules of primary reinforcement were compared in a picture-naming task with retarded children. In Experiment I, number of correct responses and learning rate were higher under fixed-ratio schedules than under continuous reinforcement. In Experiment II, number of correct responses and learning rate tended to be greater under intermediate than under low or high fixed-ratio schedules. In Experiment III, number of correct responses was higher under interlocking schedules, in which the response requirement increased with time following the previous reinforcement, than under comparable fixed-ratio schedules. Learning rates were generally low and, perhaps because of this, not very different under the two types of schedules in this experiment. Accuracy (i.e., proportion of trials on which correct responses occurred) was typically high and insensitive to variations in schedule and schedule parameter throughout each experiment.     

Nest material and food as reinforcers for fixed-ratio responding in mice

Three experiments investigated the importance of operant-reinforcer distance as a factor affecting continuous reinforcement (CRF) and fixed-ratio (FR) performance in mice, with nest material and food as reinforcers. In Experiment 1, nest material (paper strips) was presented on a series of FR schedules of increasing size, with the operandum located as close as possible to the reinforcer dispenser. Subjects compensated for increases in FR size by proportionately increasing their response output, but ratio strain occurred at low FR values. In Experiment 2, response rate was found to be inversely related to operant-reinforcer distance on a CRF schedule with nest material as reinforcer. In Experiment 3, food was presented on a series of FR schedules at two levels of deprivation, and with three operant-reinforcer distances. Operant-reinforcer distance was found to affect CRF response rate, degree of compensation for increases in FR size, and occurrence of ratio strain, but only when deprivation level was low. The results support the view that nest material and food share fundamentally similar reinforcing properties, but that nest material is a weaker reinforcer under normal test conditions.     

Stimulus-specific contrast effects during operant discrimination learning

In two experiments, pigeons' responding was equally reinforced in the presence of four line-orientation stimuli. Responding was then reinforced when only two of the four orientation stimuli were present; the remaining two orientations appeared during extinction. Response rates were often highest in the stimulus adjacent to the orientations presented during extinction and often lowest in that orientation adjacent to the orientations presented with reinforcement. These effects were stronger and more persistent when the stimuli were separated by a smaller angle, rendering the discrimination more difficult. These and other data suggest that discrimination training may not be accurately explained in terms of the simple effects of reinforcement and nonreinforcement associated with isolated stimuli, nor by accounts that depend upon stimulus generalization. Recent accounts of contrast that depend upon “emotionality” produced by nonreinforced responding or upon reinforcement-elicited responses are also difficult to apply to these data.     

Effects of computer-mediated vocational guidance procedures: Accuracy of self-knowledge

To assess the effectiveness of vocational guidance procedures proposed for inclusion in a computer-based vocational exploration system, 128 11th-grade male subjects were randomly assigned to three experimental groups and a control group. One group was given a computer-generated accuracy of self-knowledge feedback, another group was taught on occupational classification scheme, a third group experienced both. Measures of self-knowledge showed increased accuracy about intelligence, but not about interests, after treatments that included the feedback. Increases were largely due to changes in subjects who originally underestimated their intelligence. A delayed posttest indicated that the increases did not persist.     

Job specialization,work values,and worker dissatisfaction

The recent work literature includes three contradictory propositions relating job specialization and worker dissatisfaction. The first proposition predicts an unconditional relationship between these variables; the second proposition predicts that this relationship will be higher among workers committed to middle-class work values; the third proposition predicts that the relationship will be higher among “alienated” workers. This paper reports the findings of a study of 3193 British industrial workers which suggest that, when individually measured and analyzed, task attributes relate in different ways and in varying degrees to worker dissatisfaction. The implication for the above propositions is that they may be complementary rather than competing; the validity of each may depend upon how job specialization is measured.     

Strong Vocational Interest Blank basic interest clusters and occupational satisfaction

A Q-factor analytic technique applied to the Strong Vocational Interest Blank (SVIB) basic interest scales of 156 males yielded three bipolar factors described as conceptual (applied vs theoretical thinking); interpersonal (people vs things); and volitional (autonomy vs structure). From these results the investigators constructed a model for categorizing occupations into corresponding vocational areas: managerial vs academic, social vs physical sciences, and professional vs technical. Each individual's primary interest area and occupational status relative to the six corresponding areas was then determined. The degree of fit between interests and job categorization related significantly to ratings of job satisfaction (p < .001). Those findings are complementary to Holland's notion that interests are expressions of psychological needs and to Lofquist and Dawis' perception of interests and jobs as needs and need reinforcers.