Foreperiod and visual stimulus intensity: A reappraisal

The joint effects of stimulus modality, stimulus intensity, and foreperiod on simple RT were investigated. In experiment 1 an interaction was found between stimulus intensity, both visual and auditory, and a variable FP such that the intensity-effect on RT was largest at the shortest FP. Experiment 2 provided a successful replication with smaller and weaker visual stimuli. No interaction was observed with a constant FP, although the visual stimuli were identical and the auditory ones psychophysically equivalent to the visual stimuli of experiment 1.It is proposed that an additive or interactive relationship between stimulus intensity and FP can be inferred only when the mental processes called for by the various uses of FP are simultaneously considered. Another precondition is an adequate sampling of the intensity-continuum with special reference to the retinal size of visual stimuli.     

Obsessional slowness: a meticulous replication.

The treatment of an apparently authentic case of obsessional slowness is described. The relationship between behaviour change and emotional events is discussed. The findings replicate those of Rachman (1974).     

The effect of self-recording and social reinforcement components of parent training programs

This investigation attempted to assess the effectiveness of two components of parent training programs: (1) the effect of a self-behavior management project prior to intervention with deviant child behaviors, and (2) that of social reinforcement from peers and the consultant. Four groups of parents were exposed to a basic training program and were measured on their success in an intervention program in the inappropriate behavior of their children (ages 7–9 years). Two groups of parents were requested to do a self-modification program prior to the intervention with deviant child behavior; two groups did a child intervention program without a self-management project. One group in the self-management and one group without self-management received verbal social reinforcement from peers and the consultant during interventions. Results obtained indicate that the parent group whose training involved a self-behavior management project prior to intervention with their child's inappropriate behavior and verbal social reinforcement achieved a significantly greater reduction of these behaviors when compared to the groups where either self-management of social reinforcement was used.     

Perspective ability: The relative difficulty of the other observer's viewpoints

Previous research findings regarding the relative difficulty of the different positions occupied by the other observer in a perspectives task are contradictory; this may be due to a lack of control of the object arrangement and differences in masking from each viewpoint. In the present experiment, an object array was employed in which the views from the experimental positions were objectively of equal difficulty. Children of 6, 8, and 10 years found that representing the 90 and 270° views was equally difficult, but both of these views were easier than the 180° view.     

Conservation training in four-year-old children

In Experiment 1 two training procedures were used to teach four-year-olds to conserve. Verbal rule instruction consisted of providing verbal rules and demonstrations of the operations referred to by the rules. Feedback consisted of providing verbal feedback contingent upon the children's responses. One week after training on conservation of number and length the children were given a posttest which included tests of conservation of number, length, and mass. Children who were given verbal rule instruction conserved significantly more on the number and length posttest problems than children who were not. However, this learning did not transfer to the mass problems, possibly because mass is not naturally acquired until some time after conservation of number and length. The feedback training procedure had no effect on conservation performance. In Experiment 2, the verbal rule instruction procedure was used to train four-year-olds on conservation of length and mass. One week after training the children were tested on both conservation of number, which is typically acquired before length and mass, and conservation of weight, which is typically acquired after length and mass, as well as on conservation of length and mass. Children who were given training conserved more on all four types of problems than children in the control group.     

Effects of differential reinforcement and task difficulty on preschoolers' compliance with teacher instructions

Preschool children in day schools were given instructions to complete certain tasks. Four tasks were given of two types and two levels of difficulty. In each condition compliance with at most one instruction (one task) was reinforced. In two similar experiments, with six children, general results were: compliance with easy tasks was maintained without reinforcement when any task compliance was reinforced; compliance for hard tasks remained high only when that specific task was reinforced. Thus, generalization of compliance with instructions varied with task difficulty. The setting and procedure for both studies were designed to reduce possible coercive features of laboratory studies of generalized performance. Results show generalized performance can occur under naturalistic conditions. The effect of effort, as a response characteristic affecting generalized performance, is discussed.     

Control of observing by antecedent stimuli

Five pigeons were run on a one-key discrete trials observing procedure. Trial onset was signaled by a white or yellow key light. Pecks in white or yellow intermittently produced S⁺ and S⁻, green and red key lights that signaled whether the trial would end with response-independent grain reinforcement or nonreinforcement. In the Redundant conditions, white and yellow were correlated with trial outcome, making S⁺ and S⁻ redundant. In the Informative condition, white and yellow were uncorrelated with trial outcome, so that S⁺ and S⁻ provided new information. During the Informative condition, all birds responded in the formerly positive, now uncorrelated color at higher rates than they did during the preceding or succeeding Redundant conditions, in which that same color was positively correlated with primary reinforcement. This result confirmed the prediction that an animal will observe at higher rates in the absence of reinforcement-correlated cues than in their presence.     

Behavioral contrast produced by a signaled decrease in local rate of reinforcement

Pigeons' key pecking in the presence of one stimulus (S1) was reinforced according to a response-dependent variable-interval schedule. Pecking rate during S1 increased (behavioral contrast) when a second stimulus (S2) [associated with either a response-dependent fixed-interval schedule (Experiment I) or a response-independent reinforcement schedule in which reinforcement availability was signaled by visual (Experiment II) or temporal (Experiment III) stimuli] alternated with S1. These experiments suggest that a discriminable, signaled decrease in local reinforcement rate during S2 is an antecedent of the behavioral contrast response rate increases during S1.     

Adult-child discourse: Developmental interaction between information processing and linguistic knowledge

In the present study, the discourse interaction between adult and child was examined in terms of the content of their utterances, and the linguistic and contextual relations between their messages, in order to investigate how children use the information from adults' input sentences to form contingent responses. The analyses described were based on longitudinal data from four children from approximately 21 to 36 months of age. Categories of child discourse, their development and their interactions with aspects of prior adult utterances form the major results of the study. Child utterances were identified as adjacent (immediately preceded by an adult utterance), or as nonadjacent (not immediately preceded by an adult utterance). Adjacent utterances were either contingent (shared the same topic and added new information relative to the topic of the prior utterance), imitative (shared the same topic but did not add new information), or noncontingent (did not share the same topic). From the beginning, the adjacent speech was greater than nonadjacent speech. Contingent speech increased over time; in particular, linguistically contingent speech (speech that expanded the verb relation of the prior adult utterance with added or replaced constituents within a clause) showed the greatest developmental increase. Linguistically contingent speech occurred more often after questions than nonquestions. The results are discussed in terms of how the differential requirements for processing information in antecedent messages is related to language learning.