Between-chains and within-chain speed gradients as functions of length

Two experiments examined between-chains and within-chain speed gradients as functions of length. The first, involving straight runways, revealed hyperbolic gradients within chains for each of three lengths, .61, 1.22, and 2.44 m. Between-chains comparisons showed a goal gradient effect confined to the start box segment and a long-chain depression effect in the last two segments. The second experiment, involving discrete-trial fixed-ratio bar-pressing schedules of FR(1 + 4), FR(1 + 8), and FR(1 + 16), showed goal gradient effects for starting speeds and for speeds across the first segment beyond start. Also, confounding effects apparent in the runway, of acceleration, deceleration, and long-chain depression, were diminished or absent in the bar-pressing situation.     

Effects of prefeeding on performance with body weight held constant

Two experiments are reported in which rats received either no prefeeding, nutritive substance prefeeding, or nonnutritive substance prefeeding prior to running in a straight alley. The running-speed data supported body weight as an overall measure of hunger drive. Performance was a function of body weight but not stomach weight or associated stomach bulk.     

A behaviorally-based measure of manifest needs in work settings

This investigation represents an attempt to develop and validate a research instrument (Manifest Needs Questionnaire) capable of measuring the four needs of achievement, affiliation, autonomy, and dominance using behaviorally-based scales. The instrument is designed to measure such needs with specific reference to work settings and with minimal time requirements for completion. Results of both laboratory and field studies among 640 subjects indicate that the instrument exhibits acceptable levels of convergent, discriminant, and predictive validity, as well as reasonably high test-retest reliability and internal consistency. Results are compared to other, lengthier instruments designed to measure similar needs.     

Structural ambiguity in serial pattern learning

Four experiments on serial anticipation learning of lights by college students show that (a) the operations of transposing and taking the mirror image are used, (b) temporal inversion is not used, (c) a sequence made of two contrasting halves may be as easy to learn as a sequence having a single homogeneous hierarchical structure. Data revealed intrasequence confusion errors made by importing an operation from one part of the sequence to another. In homogeneous sequences, subjects appear to lose track of where they are in a sequence, and therefore repeat an operation already performed. The evidence supports the idea of an hierarchical cognitive structure, but shows that learning is not a simple function of that structure. Errors and difficulties arise from structural ambiguities, substrings of events that can be reconciled with more than one possible cognitive structure.     

Eliminating nail-biting by the habit reversal procedure

Fingernail-biting is prevalent among children and adults alike. About 43% of children bite their nails during the puberty ages (Wechsler, 1931); 25% of college students are nail-biters (Coleman and McCalley, 1948), and 10% of adults bite their nails (Pennington, 1945).A variety of treatments including negative practice, operant procedures and psychotherapy have been used in treating nail-biting but no single treatment has been generally effective in eliminating nail-biting. Smith (1957) using negative practice reported that 21 of 57 (39%) of his nail-biting clients were cured. 9 improved and 27 (47%) were unimproved. Bucher (1968) reported that 13 of 20 (65%) college students stopped nail-biting by using a self-administered operant shock procedure. However, he reported many relapses after the withdrawal of shock for nail-biting. No evaluation of psychoanalytic treatment for nail-biting appears to have been made.     

The Premack principle in human experimental and applied settings

Studies claiming support for the Premack Principle in human experimental and applied settings are reviewed in terms of the standard test conditions associated with the Principle and in terms of the Principle's conceptual constrains. Little definitive evidence was found to support the claim that a high probability response will reinforce a lower probability response, nor was the converse contention supported, that a low probability response will act as a punisher for a high probability response. More importantly, among the reports reviewed there was no evidence for the reversibility of the reinforcement relationship.     

The abstraction of visual prototypes by children

The present studies demonstrated that children as young as second graders could form prototypical representations from a set of highly similar stimuli. The prototype-plus-transformation model of this performance (Franks & Bransford, 1971) was contrasted with an attribute-frequency model (Neumann, 1974). Results supported the latter model when trigram stimuli were used to test differential predictions from the models.     

The effect of pictorial detail and elaboration on children's retention.

In a visual memory task, two degrees of stimulus detail were compared to test Reese's hypothesis that stimulus detail would facilitate retention of paired associates for young children. Stimuli were presented in an elaborated or nonelaborated fashion so that the effect of detail on retention of both types of materials could be investigated. Four and 5 year-old children were included to assess a reported developmental trend that elaboration facilitates retention for older children but fails to do so for younger children. Both age groups performed equally well, and detail had no effect. Elaboration aided retention significantly. A second study, in which difficulty of the task was increased, yielded equivalent results. The constraints on performance by recall and recognition tasks were discussed.     

Spatial representation by blind and sighted children

Spatial representation by 72 blind and blindfolded sighted children between the ages of 6 and 11 was tested in two experiments by mental rotation of a raised line under conditions of clockwise varied directions.Experiment 1 showed that the two groups were well matched on tactual recognition and scored equally badly on matching displays to their own mentally rotated position.Experiment 2 found the sighted superior in recall tests. There was a highly significant interaction between sighted status and degree of rotation. Degree of rotation affected only the blind. Their scores were significantly lower for rotating to oblique and to the far orthogonal directions than to near orthogonal test positions. On near orthogonals the blind did not differ from the sighted.Age was a main effect, but it did not interact with any other variable. Older blind children whose visual experience dated from before the age of 6 were superior to congenitally blind subjects, but not differentially more so on oblique directions.The results were discussed in relation to hypotheses about the nature of spatial representation and strategies by children whose prior experience derived from vision or from touch and movement.