Age-related differences in reaction time task performance in young children

Performance of reaction time (RT) tasks was investigated in young children and adults to test the hypothesis that age-related differences in processing speed supersede a “global” mechanism and are a function of specific differences in task demands and processing requirements. The sample consisted of 54 4-year-olds, 53 5-year-olds, 59 6-year-olds, and 35 adults from Russia. Using the regression approach pioneered by Brinley and the transformation method proposed by Madden and colleagues and Ridderinkhoff and van der Molen, age-related differences in processing speed differed among RT tasks with varying demands. In particular, RTs differed between children and adults on tasks that required response suppression, discrimination of color or spatial orientation, reversal of contingencies of previously learned stimulus-response rules, and greater stimulus-response complexity. Relative costs of these RT task differences were larger than predicted by the global difference hypothesis except for response suppression. Among young children, age-related differences larger than predicted by the global difference hypothesis were evident when tasks required color or spatial orientation discrimination and stimulus-response rule complexity, but not for response suppression or reversal of stimulus-response contingencies. Process-specific, age-related differences in processing speed that support heterochronicity of brain development during childhood were revealed.     

An automated identification system for use with computer-controlled tasks

Monkeys of various species can use a joystick to perform a variety of computer-generated tasks. The purpose of this paper is to describe an automated system that determines which subject in a social group has completed a task. The system is based on a microchip that is easily injected into the forearm. The present paper demonstrates the technique with 1 animal that had a different chip in each arm.     

The effect of orthographic similarity on lexical retrieval: Resolving neighborhood conflicts

This paper reviews recent research on the effects of orthographic neighbors on visual word recognition in order to resolve apparently contradictory findings. The review reveals that the empirical evidence is not as contradictory as has been claimed. Neighbors have consistently been reported to facilitate responses to words in naming and lexical decision tasks. Inhibitory effects of neighbors appear to arise from sophisticated guessing strategies in the perceptual identification task or lexical decision strategies adopted in unusual stimulus environments. For English words, there is minimal evidence of competitive influences on lexical retrieval due to higher frequency neighbors. Such effects are more common in such languages as French and Spanish, perhaps because they embody a more consistent relationship between orthography and phonology. These findings provide important constraints on assumptions about the form of lexical representations and the parallel activation mechanisms assumed to underlie lexical retrieval.     

Cocaine-induced brainstem seizures and behavior

A variety of abnormal sensory/motor behaviors associated with electrical discharges recorded from the bilateral brainstem were induced in adult WKY rats by mechanical (electrode implants) and DC electrical current stimulations and by acute and chronic administration of cocaine. The electrode implant implicated one side or the other of the reticular system of the brainstem but subjects were not incapacitated by the stimulations. Cocaine (40 mg/kg) was injected subcutaneously for an acute experiment and subsequent 20 mg/kg doses twice daily for 3 days in a chronic study. Cocaine generated more abnormal behaviors in the brainstem perturbation group, especially the electrically perturbated subjects. The abnormal behaviors were yawning, retrocollis, hyperactivity, hypersensitivity, “beating drum” behavior, squealing, head bobbing, circling, sniffing, abnormal posturing, and facial twitching. Shifts in the power frequency spectra of the discharge patterns were noted between quiet and pacing behavioral states. Hypersensitivity to various auditory, tactile, and visual stimulation was present and shifts in the brainstem ambient power spectral frequency occurred in response to tactile stimulation. These findings suggest that the brainstem generates and propagates pathological discharges that can be elicited by mechanical and DC electrical perturbation. Cocaine was found to activate the discharge system and thus induce abnormal behaviors that are generated at the discharge site and at distant sites to which the discharge propagates. Cognitive functions may also be involved since dopaminergic and serotonergic cellular elements at the brainstem level are also implicated.     

Beyond the high point code in testing Holland's theory

This study was designed to test and expand Holland's vocational development theory by utilizing more than a single high point code in classification of personality patterns of jobs. Significant positive results were obtained to support Holland's premise that people search out environments and, hence, vocations that are compatible with their personalities. A more “refined” and/or “subtle” difference was shown in the personality-job relationships when two high point codes were used.     

Semantic organization in deaf and hearing subjects

Hierarchical cluster analysis of data from the sorting of noun words was used to compare semantic structures in 63 profoundly deaf and 63 hearing adolescents. In the first study, performance differed only for a set of words referring to sounds, where deaf persons have no experience, and not for a set of common noun words and pictures. In the second study, differences between matched sets of high- and low-imagery words were comparable for 63 deaf and 63 hearing subjects. It is concluded that deaf subjects manifested abstract hierarchical relations and were not dependent on visual mediators or hindered by the absence of acoustic mediators.This investigation was supported in part by National Institutes of Health Research Grant NS-09590-03 from the National Institute of Neurological Diseases and Stroke and in part by a Faculty Research Grant from Bowling Green State University.Portions of Study 1 were previously reported at the Eighty-first Annual Convention of the American Psychological Association, Montreal, 1973.     

A self-administered program for public speaking anxiety.

Therapist-administered desensitization was compared with a take-home manual for self-administering desensitization, where the self-administering subjects had varying degrees of contact with therapists. These treatments were compared with an attention-placebo procedure and no-treatment controls. None of the treatment procedures had any effect on behavioural manifestations of anxiety in public-speaking phobics, but all treatment subjects showed greater reductions in subjective anxiety than either of the control groups. The drop-out rate was greatest for the no-contact manual group indicating the value of brief supervision in its use. The implications of the failure to change overt behaviour in view of Paul's (1966) earlier findings, are discussed.     

Skills training and self-administered desensitization in the reduction of public speaking anxiety.

The aim is to test the following hypotheses. Since desensitization targets only “feelings” of anxiety, and skills training targets only overt behaviors, the predictions based on the earlier findings (Marshall, Presse and Andrews, 1976; Paul, 1966) are as follows: (a) the combination of skills training and desensitization will be more effective than desensitization alone, but no more effective than skills training alone, in reducing behavioral manifestations of anxiety; (b) the combination will be more effective than skills training alone, but no more effective than desensitization alone, in reducing subjective distress; (c) skills training will be more effective than desensitization in reducing behavioral manifestations of anxiety; and (d) desensitization will be more effective than skills training in reducing subjective distress.     

Induction of Relational Schemas: Common Processes in Reasoning and Complex Learning

Five experiments were performed to test whether participants induced a coherent representation of the structure of a task, called a relational schema, from specific instances. Properties of a relational schema include: An explicit symbol for a relation, a binding that preserves the truth of a relation, potential for higher-order relations, omnidirectional access, potential for transfer between isomorphs, and ability to predict unseen items in isomorphic problems. However relational schemas are not necessarily coded in abstract form. Predictions from relational schema theory were contrasted with predictions from configural learning and other nonstructural theories in five experiments in which participants were taught a structure comprised of a set of initial-state,operator → end-state instances. The initial-state,operator pairs were presented and participants had to predict the correct end-state. Induction of a relational schema was achieved efficiently by adult participants as indicated by ability to predict items of a new isomorphic problem. The relational schemas induced showed the omnidirectional access property, there was efficient transfer to isomorphs, and structural coherence had a powerful effect on learning. The “learning to learn” effect traditionally associated with the learning set literature was observed, and the long-standing enigma of learning set acquisition is explained by a model composed of relational schema induction and structure mapping. Performance was better after reversal of operators than after shift to an alternate structure, even though the latter entailed more overlap with previously learned tasks in terms of the number of configural associations that were preserved. An explanation for the reversal shift phenomenon in terms of induction and mapping of a relational schema is proposed. The five experiments provided evidence supporting predictions from relational schema theory, and no evidence was found for configural or nonstructural learning theories.