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.     

Referenzsemantik in der Partnermodellierung

How can we explain that an assertion on something perceived can be understood in the same manner by somebody who cannot perceive that scene? This problem bases the interest in computational linguistics in how listener modeling could possibly be harmonized with reference semantics. Mental images substituting real perception appear as a way out. The architecture of the listener model has to be adapted to the creation and use of such pictorial data structures. Furthermore, the relation between the latter and a verbal (i. e., propositional) representation must be understood. The resulting architecture of a listener model with reference semantics can be employed to solve communicational problems from three general classes in a better way, as is demonstrated by an example implementation.     

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.     

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.     

On the time course of negative priming: Another look

In two experiments, the pattern of persistence of negative priming effects across delay intervals of 500 and 2,500 msec was assessed using a within-subjects, random sequencing of delays. Neill and Valdes (1992; Neill, Valdes, Terry, & Gorfein, 1992) have argued that a within-subject experimental design is required for decay of negative priming to be seen, in contrast to results reported elsewhere (e.g., Tipper, Weaver, Cameron, Brehaut, & Bastedo, 1991) showing stable negative priming effects across delays. In neither experiment was substantial evidence of decay detected, raising questions for the notion that suppression necessarily declines across brief temporal intervals and for the assertion that episodic retrieval is the sole source of negative priming.     

PROFESSIONAL NETWORKS OF JUNIOR FACULTY IN PSYCHOLOGY

Composition and functioning of academics' professional networks were assessed in a study of 47 women and 43 men holding tenure-track assistant professor positions in psychology at sixty universities. Women's networks had significantly more women colleagues, more higher-status women colleagues, and fewer associates from their previous institutions than men's. Women also consistently rated their networks as less effective at helping them build a professional reputation. However, women were similar to men in terms of the number of "important colleagues" and higher status associates in their networks and ratings of colleagues' effectiveness at providing professional socialization, friendship, career information, and access to current research. The results suggest that by the third year at the assistant professor level, women in psychology have established a small same-sex support network, but that their larger network functioning may be beginning to diverge from men's in one important area: building a profesional reputation. Implications for women's career strategies are discussed.