Effects of schedule and magnitude of reinforcement under conditions of thirst motivation

In contrast to a recent finding (Macdonald, G. E., & De Toledo, L. Learning and Motivation, 1974, 5, 288–298.) the results of three experiments investigating various partial reinforcement (PRF) manipulations under conditions of thirst motivation demonstrated strong similarity to analogous manipulations involving food reward. Specifically, for animals receiving water reinforcement, PRF was shown to generate greater resistance to extinction than continuous reinforcement (Expt 1 & 3), the schedule of reinforcement was shown to interact with level of acquisition (Expt 1 and 2), and the magnitude of the partial reinforcement extinction effect was shown to be a function of reward magnitude (Expt 3). These results provide strong evidence that mechanisms which operate in partial reinforcement situations are highly similar, regardless of the type of appetitive reinforcement.     

Processing strategies in sentence comprehension

Response latencies in sentence-picture verification tasks were compared as a function of whether a mismatch was located in the logical subject (LS), verb (V), or logical object (LO) of the sentence. Sentences were presented auditorily and varied in voice and reversibility. The comparison process for nonreversibles was clearly serial self-terminating: latencies for both actives and passives were ordered LS < V < LO, or, after practice with a small number of mismatch types, LS < LO < V. Latencies for reversibles were ordered V < LS = LO, suggesting either a verb-first comparison process or an LS-V-LO comparison process which did not terminate with a subject-mismatch because of the confusability of the subject and object. The results attest to the importance of considering the "naturalness" of stimuli in sentence processing tasks, and the flexibility of subjects' encoding and comparison strategies both within and across task contexts.     

Control-system theory and performance objectives

Behaviorism, the source of the concept of performance objectives, models behavior as an output emitted by an organism. Control theory suggests a different model, in which the stable patterns called behavior are perceptual variables stabilized against disturbances by variations in motor activities. Control theory provides a clear distinction between a learning model and a performance model. Learning is centered around the control of internal variables by means of changes in the organization of performance. Performance is centered around control of perceptual variables, which the experimenter or teacher must learn to share with the subject or student in order to understand what is being performed.     

Grouping strategies, peer influence, and free time as classroom management techniques with first- and third-grade children

This study systematically investigated the effects of different procedures on classroom behaviors ranging from teacher designated seating groups and seating groups based on sociometric data to peer encouragement and free time reinforcers. Subjects were first- and third-grade children in classrooms using a Follow Through program model. Data were taken on the attending behavior of the children in small groups arranged by the teacher. The level of appropriate attending behavior was low and did not increase when the groups were restructured based on sociometric data. The introduction of instructions to the peer groups to help the child with his or her work brought about a major increase in the third-grade subjects' appropriate behavior. Appropriate attending behavior for the first-grade children did not increase to the predetermined acceptable level until a free time period for each peer group was made contingent upon the appropriate behavior of the subject in each group. Frequencies of verbal interactions suggested peer attention has an effect on the appropriateness of peer interactions.     

An audio-tactile display

Several devices have been developed enabling the blind to adapt to digital and visual displays. Most require extensive training and are relatively expensive. The audio-tactile display described in this paper requires very little training and promises to be inexpensive. Prototypes of the display have been developed for a digital stopwatch, a digital clock, and several electronic calculators. Because the device makes use of electrical impulses to communicate with the blind, it also has numerous potential capabilities as a research tool. The device is based on a panel containing columns of braille digits that are made active through a logic circuit interfacing the braille display with a calculator or other device. The subject scans the braille columns and discovers the digits active in each column when a tone is produced simultaneously with the finger contacting the braille digit.