Cholinergic-dopaminergic interactions in cognitive performance

Both acetylcholinergic (ACh) and dopaminergic (DA) systems have been found to be crucial for the maintenance of accurate cognitive performance. In a series of studies examining those aspects of cognitive function revealed by the radial-arm maze, we have found that these two neurotransmitter systems interact in a complex fashion. Choice accuracy deficits in the radial-arm maze can be induced by blockade of either muscarinic- or nicotinic-ACh receptors. The choice accuracy deficit induced by blockade of muscarinic receptors with scopolamine can be reversed by the DA receptor blocker, haloperidol. The specific DA D1 blocker SCH 23390 also has this effect, whereas the specific D2 blocker raclopride does not, implying that it is D1 blockade that is critical for reversing the scopolamine effect. On the other hand, the choice accuracy deficit induced by nicotinic blockade with mecamylamine is potentiated by haloperidol. This effect is also seen with the D2 antagonist raclopride, but not with the D1 antagonist SCH 23390, implying that it is the D2 receptor which is important for the potentiation of the mecamylamine effect. The relevance of the D2 receptor for nicotinic actions on cognitive function is emphasized by the finding that the selective D2 agonist LY 171555 reverses the choice accuracy deficit caused by mecamylamine. Nicotinic and muscarinic blockade are synergistic in the deficit they produce. Antagonist doses subthreshold when given alone produce a pronounced impairment when given together. This latter deficit can be reversed by the D2 agonist LY 171555. These studies have outlined the complex nature of ACh-DA interactions with regard to cognitive function. Possible neural circuits for these interactions are discussed. The effectiveness of these selective DA treatments in reversing cognitive deficits due to ACh underactivation suggests a novel approach to treating cognitive dysfunction in syndromes such as Alzheimer's disease.     

The electronic teaching theater: Interactive hypermedia and mental models of the classroom

The introduction of hypermedia into the classroom presents both an opportunity to expand the power of teaching through electronic facilitation of the media and a challenge to redesign the classroom and instructional environment to exploit the enhanced features of hypermedia. This paper briefly surveys the current state of computers in the classroom and then argues that a more integrated approach is required. To this end, the concept of an electronic teaching theater is proposed which takes advantage of hypermedia and collaborative work environments. The aim of the electronic teaching theater is not to totally redesign the classroom and instructional interaction, but rather to facilitate it using well understood metaphors to lay out the dynamics of classroom interaction on the electronic media and to use the results from research in human/computer interaction to design the interface. To facilitate the application of hypermedia, a model of instructional interaction among the students, the instructors, the course material, and the products of instruction is presented. A number of component models pertaining to course preparation, lectures, note taking, and other instructional activities are then discussed that should prove useful in designing the electronic classroom. The origin of these models is the mental representation of the interaction as perceived by the teacher and the student. The idea is to start with such models as a base metaphor, to instantiate the metaphors in the electronic classroom, and then to explore innovations in the technology that go beyond the strict application of the metaphor. This work was supported in part by a grant from AT&T to the University of Maryland during the author’s visit to the Medical Research Council—Applied Psychological Unit, Cambridge, England. Appreciation is expressed to Patricia Wright and Richard M. Young for their helpful comments on this paper.     

Neural Network Models and Mechanisms of Strategy Development

The focus of this paper is mechanisms that may be responsible for intellectual and developmental differences in the cognitive strategies of typical and atypical children, including those with mental retardation. The discussion of these mechanisms is based on behavioral experiments on external memory strategies and on a set of neural network models designed for these tasks. Following the review of the external memory research, the rationale for using neural network models, how they have been used in other research, and their specific application to intellectual and developmental differences in external memory, including the results of several simulations, are reviewed. This is followed by a discussion of the mechanisms of intellectual differences and developmental change included in the models and some challenges for this type of modeling. Neural network modeling is discussed as an asset to research on cognitive development.     

Whatever Happened to Culturalism: From Horney to Lacan

The American Journal of Psychoanalysis -     

Child abuse and neglect by parents with disabilities: A tale of two families

Two families, in which the children had been placed in foster care due to abuse and neglect by parents who had disabilities, were studied. In the first case, the mother was instructed in skills that our assessment suggested were important for her child's survival. The mother readily acquired and applied these skills, a fact reflected both in changes in her behavior and in changes in the child's well-being. In the second case, the parent's incremental resumption of child custody was made contingent upon completion of relevant parenting tasks. Initially, improvements in the completion of such tasks were evident, but over time and with the onset of militating factors, no further progress was made and all parental rights were terminated. The implications of these cases for behavior analysis and the effort to reunite and preserve families are discussed.     

Anxious attachment and psychological distress in cardiac rehabilitation patients

This study investigated the relevance of anxious attachment to the differentiation of psychologically distressed and non-psychologically distressed cardiac patients. Attachment is a biologically based behavioral system in which proximity to a special other is sought or maintained to achieve a sense of safety and security. Anxious attachment, as the name denotes, fails to achieve the function of attachment in the sense of individuals having little or no confidence in the availability of their attachment figures. Empirically, three scales (feared loss of the attachment figure, proximity seeking and separation protest) capture the features of anxious attachment as elaborated by Bowlby. These scales were administered to 178 cardiac rehabilitation patients drawn from the cardiac rehabilitation program of the Calgary General Hospital. The results indicate that feared loss and proximity seeking differentiated psychologically distressed from non-psychologically distressed patients. The implications of this finding for the understanding of psychologically distressed cardiac patients are discussed.     

Content validity: A neglected strategy for developing managerial selection tests?

There is a lack of quick, valid, and cost effective methods for selection of low-and mid-level managerial personnel. Using content-valid methods to develop managerial selection instruments may reap substantial benefits for applicants as well as for the organizations using such tools. To this end, based upon extensive job analysis, a content-valid managerial selection test was developed. Criterion-based validity collected on the new instrument suggested that an instrument developed using content-valid procedures can also show acceptable levels of criterion validity.     

Accreditation Standards for University and College Counseling Centers

The accreditation standards outlined in the article are used by the International Association of Counseling Services, Inc., as the basis for the formal accreditation of college and university counseling programs throughout the United States and Canada. They reflect the program elements and practice standards that are deemed essential in a counseling center that provides high-quality services to students.     

Gender,psychological well-being and somatic cardiovascular risk factors

The purpose of this study is to determine associations between cardiovascular risk factors and subjective experience of psychological general well-being with special reference to gender-related differences. One hundred fifty white-collar workers in a car manufacturing plant in Sweden participated in a health care screening program. Subjective experience of psychological well-being was significantly correlated with cardiovascular risk factors among both men and women. There were, however, marked differences between the genders. For men, the following specific psychological variables were significantly correlated with cardiovascular risk factors: estimation of general health, anxiety, self-control and vitality. For women, more complex significant relationships between the two sets of variables were found. Moreover, the direction of the correlations differed between the genders. For example, men with cardiovascular risk factors, such as increased blood pressure, blood lipids and body mass index, reported significantly morepositive estimation of their general health. For women the relation was the opposite with a significantly positive correlation (p-0.004) between experience of good health and a low risk factor profile indicating the concordance between physiological and psychological parameters. Possible reasons for these sex differences are discussed.