A microcomputer-controlled laboratory: Software

The software used in a microcomputer-controlled laboratory is described. Primary emphasis is placed upon describing the capabilities of a powerful, easy-to-use programming language appropriate for controlling research in a wide variety of applications. It is particularly appropriate for physiological and operant laboratories. Design of the language and accompanying operating system follow a rigorous modular, structured approach, with most coding done in high-level languages. As a result, the code is easy to maintain and expand. In addition, it is not difficult to adapt the programs to other microprocessors to take advantage of a rapidly improving technology.     

Age and sex differences in the development of children's occupational reasoning

The purpose of this study was an investigation of age and sex differences in the thinking processes that underlie children's occupational choices and their perception of adult roles. Subjects were 48 nursery school children (24 3-year-olds and 24 4-year-olds) and 48 third graders, all middle class, evenly divided by sex. Subjects were interviewed, using a modified form of Van Den Daele's Ego Ideal interview, on what they wanted to be when they grew up, their reasons for their choices, and their knowledge of means and ends regarding their choices. They were also asked what they would want to be if they were of the opposite sex. Tape-recorded responses were evaluated according to Van Den Daele's Ego Ideal levels. Analyses of variance indicated significant (p < .0001) changes of level with age. Sex differences were less pronounced and inconsistent. The range of occupations tended to increase with age, and both boys and girls expressed a broader range of choices for themselves than they did for the opposite sex. The study demonstrates that the process of vocational development is related to cognitive development; children's choices and reasoning reflect their changing modes of understanding the world.     

Cross-species differences in color categorization

Berlin and Kay (1969) found systematic restrictions in the color terms of the world’s languages and were inclined to look to the primate visual system for their origin. Because the visual system does not provide adequate neurophysiological discontinuities to supply natural color category boundaries, and because recent evidence points to a linguistic origin (Davidoff, Davies, & Roberson, 1999), a new approach was used to investigate the controversial issue of the origin of color categories. Baboons and humans were given the same task of matching-to-sample colors that crossed the blue/green boundary. The data and consequent modeling were remarkably clear-cut. All human subjects matched our generalization probe stimuli as if to a sharp boundary close to the midpoint between their training items. Despite good color discrimination, none of the baboons showed any inclination to match to a single boundary but rather responded with two boundaries close to the training stimuli. The data give no support to the claim that color categories are explicitly instantiated in the primate color vision system.     

The effects of metabolic stress and vagotomy on emotional learning in an animal model of anxiety

The aim of the present study is to evaluate the role of the blood glucose (BG) level in emotional learning in the elevated plus maze (EPM), an animal model of anxiety. In Experiment 1, male Wistar rats were submitted to different EPM trial lengths (1- or 5-min). Blood samples were withdrawn before and after the maze exploration, through a polyethylene cannula chronically implanted into the jugular vein. In Experiment 2, the animals received either saline or 2-deoxy-D-glucose, a glucoprivic drug (2-DG, 250 or 500 mg kg(-1)) by i.p. route, 30 min before a 5-min EPM exposure and were retested in the maze (Trial1/Trial2 EPM procedure) 24 h later. In an independent group of rats, blood samples were withdrawn 0, 5, 15, and 30 min after 2-DG administration, through the jugular vein, to determine BG. In Experiment 3, the animals underwent a vagotomy and were tested in a Trial1/Trial2 EPM procedure four weeks later. The results showed that rats exploring the EPM for 5 min displayed increased fear and higher hyperglycemia than those exploring the EPM for 1 min. In addition, rats submitted to 5-min EPM Trial1 length displayed higher level of fear on Trial2, as well as higher percentage of shortening of the %Open arm entries and %Open arm time from Trial1 to Trial2, which characterizes the occurrence of emotional learning. In contrast, rats previously vagotomized or treated with 2-DG (500 mg kg(-1)) showed the same level of fear on both EPM trials and a low percentage of shortening, from Trial1 to Trial2, of the %Open arm entries and %Open arm time, indicating poor emotional learning. The data is discussed regarding the role of glycaemia in emotional learning in the EPM.     

Learning under stress: how does it work?

The effects of stress on learning and memory are not always clear: both facilitating and impairing influences are described in the literature. Here we propose a unifying theory, which states that stress will only facilitate learning and memory processes: (i) when stress is experienced in the context and around the time of the event that needs to be remembered, and (ii) when the hormones and transmitters released in response to stress exert their actions on the same circuits as those activated by the situation, that is, when convergence in time and space takes place. The mechanism of action of stress hormones, particularly corticosteroids, can explain how stress within the context of a learning experience induces focused attention and improves memory of relevant information.     

Intellectual development of infants, children and adolescents with congenital heart disease

Cardiac disease is the most common congenital defect in children, affecting between 3 and 10 in every 1000 live births. While significant advances in medical and surgical management have resulted in increasing numbers of survivors, it is also recognized that there is a growing population of children living with neurological impairment and lowered intellectual function. The aetiology of such impairment is multi-factorial and hypoxia is one of the factors involved. This article provides an overview of the effects of hypoxia on the intellectual development of infants, children and adolescents with congenital heart disease.     

The role of inhibitory control in the production of misinformation effects

Recent research has indicated a link between retrieval-induced forgetting and the production of misinformation effects (J. Saunders & M. D. MacLeod, 2002). The mechanism underlying this relationship, however, remains unclear. In an attempt to clarify this issue, the authors presented 150 participants with misinformation under conditions designed to promote the activation of inhibitory control during the retrieval of information about a target event. A modified retrieval practice paradigm that used the independent probe method pioneered by M. C. Anderson and B. A. Spellman (1995) revealed that misinformation effects emerged only where misinformation had been introduced about items that had been subject to 1st-order, 2nd-order, or cross-category inhibition. By contrast, misinformation effects failed to emerge where inhibitory processing had not been activated. These findings are discussed in terms of inhibitory control, memory malleability, and their implications for the interviewing of eyewitnesses.     

Developing Effective Prevention Services for the Real World: A Prevention Service Development Model

A Prevention Service Development Model (PSDM) is presented as an approach to develop prevention programs that are both effective and that are readily adopted for implementation in community settings. The model is an integration of concepts and methods from two fields, prevention research and marketing research as applied to new service development. Questions that are posed at each stage of the PSDM are described. Studies from the development of two preventive interventions are presented to illustrate research at several of the stages of the model.     

Letter-by-letter reading: natural recovery and response to treatment

The present investigation provides a longitudinal study of an individual (RB) with acquired alexia following left posterior cerebral artery stroke. At initial testing, RB exhibited acquired alexia characterized by letter-by-letter (LBL) reading, mild anomic aphasia, and acquired agraphia. Repeated measures of reading accuracy and rate were collected for single words and text over the course of one year, along with probes of naming and spelling abilities. Improvements associated with natural recovery (i.e., without treatment) were documented up to the fourth month post onset, when text reading appeared to be relatively stable. Multiple oral reading (MOR) treatment was initiated at 22 weeks post-stroke, and additional improvements in reading rate and accuracy for text were documented that were greater than those expected on the basis of spontaneous recovery alone. Over the course of one year, reading reaction times for single words improved, and the word-length effect that is the hallmark of LBL reading diminished. RB's response to treatment supports the therapeutic value of MOR treatment to in LBL readers. His residual impairment of reading and spelling one-year post stroke raised the question as to whether further progress was impeded by degraded orthographic knowledge.