Effects of two-year treatment with the cholinesterase inhibitor rivastigmine on behavioural symptoms in Alzheimer's disease

Alzheimer's disease (AD) is accompanied by prominent behavioural disturbances. They cause significant distress for both caregivers and patients and can play a major role in the decision to institutionalise AD patients. Recent evidence suggests that cholinergic deficiencies not only contribute to the memory and cognitive abnormalities of AD but are also responsible for some behavioural abnormalities seen over the course of the disease. In this study we assessed the ability of rivastigmine, a pseudo-irreversible cholinesterase inhibitor, to improve behavioural and psychopathologic symptoms in AD. The analysis included 34 patients present in the Germanarm of the international study B303 who received and completed long-term treatment with rivastigmine in the open-label study B305. Assessments of behaviour and psychopathological symptoms were performed using the behavioural component of the Clinicians Interview Based Impression of Change Plus (CIBIC-Plus). Results show that long-term treatment with rivastigmine can slow the progression of behavioural and psychopathological symptoms of AD. Behavioural symptoms showing stabilisation included aggressiveness, activity disturbances, hallucinations and paranoid features. Results also suggest that patients treated earlier with rivastigmine may attain a greater benefit compared with patients whose treatment is delayed 6 months. Further studies examining the effects of rivastigmine on behavioural disturbances in AD are therefore warranted.     

Computational evidence for the foundations of numerical competence

INFANT is a computational model of Simon's (1997) ‘non-numerical’ account of the foundations of numerical competence. It operationalizes the memory, individuation, object permanence and spatiotemporal representation competencies of that account into a simulation of the Simon, Hespos & Rochat (1995) study. Results demonstrate that infants’ responses can indeed be reproduced without numerical representations.     

Sex differences in physical,verbal, and indirect aggression: A review of recent research

In the present article, recent research on sex differences in aggressive styles is reviewed. The concept of indirect aggression is particularly presented and discussed. It is argued that it is incorrect, or rather, nonsensical, to claim that males are more aggressive than females. A theory regarding the development of styles of aggressive behavior is presented.     

Care-oriented moral reasoning and prosocial behavior: A question of gender or sex role orientation

Sex Roles - The possibility that sex role orientation was a better predictor of care-oriented moral development than gender for both men and women was investigated in this study. Also, the...     

The dual-conception view reexamined: attentional demands and the encoding of verbal and physical information in action events

In two experiments the influence of attentional demands at encoding on recall of different features of subject-performed tasks (SPTs) was studied. In Experiment 1, memory of verbs and colors of objects was tested, with object names serving as cues. In Experiment 2, object and color memory were tested, with verbs serving as cues. Results from both experiments indicated that SPTs were affected by divided attention at encoding. In contrast to previous research, verbal and physical properties of SPTs were not differently affected by the requirements of dual-task performance (i. e., the combination of an SPT task and a secondary task). The results are discussed in terms of the nature of the secondary task.     

Hemispheric asymmetry and human associative learning: Interactions with attention

In a previous study (Hugdahl & Brobeck, 1986) it was shown that Pavlovian conditioning to an auditory verbal conditioned stimulus (CS) initially presented only to the left cerebral hemisphere was stronger than when the same CS was presented to the right hemisphere. This was followed up in the present study by controlling for the possibility that the effect was caused by laterally biased attention. The study was performed using the “dichotic extinction paradigm,” which consists of three different phases. During the habituation phase, the CS+ and CS- were presented binaurally and separated in time. During the acquisition phase, the CS+ was followed by a white-noise unconditioned stimulus (UCS). During the dichotic extinction phase, the CS+ and CS- were presented dichotically, i.e., simultaneous presentations on each trial. Half of the subjects had the CS+ in the right ear, and half had the CS+ in the left ear. Each group was further divided into two subgroups, with one subgroup instructed to attend only to the right ear input, and the other subgroup to attend only to the left ear input. During acquisition, larger electrodermal responses were obtained to the CS+ than to the CS-. During dichotic extinction, the CS+ right ear group showed superior resistance to extinction compared to the CS+ left ear group, with no effect of the manipulation of attention. The effect was, however, attenuated when levels of acquisition was used as covariates in an analysis of covariance. There were overall larger responses from the left hand recording.     

Structural analysis of covariance and correlation matrices

A general approach to the analysis of covariance structures is considered, in which the variances and covariances or correlations of the observed variables are directly expressed in terms of the parameters of interest. The statistical problems of identification, estimation and testing of such covariance or correlation structures are discussed.Several different types of covariance structures are considered as special cases of the general model. These include models for sets of congeneric tests, models for confirmatory and exploratory factor analysis, models for estimation of variance and covariance components, regression models with measurement errors, path analysis models, simplex and circumplex models. Many of the different types of covariance structures are illustrated by means of real data.1978 Psychometric Society Presidential Address.This research has been supported by the Bank of Sweden Tercentenary Foundation under the project entitledStructural Equation Models in the Social Sciences, Karl G. Jöreskog, project director.     

Extending the temporal range of psychometric prediction by optimal linear filtering of mental test scores

Incorporating temporal decline in predictive validity into mental testing theory is outlined. Starting from multivariate regression of criterion on repeated measurements, an analytic extension results in a weighting function for repeated measurements, replacing the beta weights. Besides optimizing, the procedure permits an evaluation of any particular prognosis setting: In cases of exponentially declining predictive validity, prognostic range can be extended if concurrent validity is nonperfect by optimal weighting (predictive filtering) of repeated measurements. Considerable gain in prognostic range over the traditional approach can be achieved if predictive validity declines concavely downwards.This work was supported by grant Dr 58/3 from Deutsche Forschungsgemeinschaft.     

An inexpensive,portable, printing event recorder for behavior studies

An inexpensive, field-portable event recorder for monitoring insect or other animal behavior is described. The recorder consists of a 16-key event code keyboard and a 99.99-min timer interfaced to a low-cost printing calculator. The event code number and the elapsed time (.01-min resolution) from the start of an observation period are printed whenever an event key is pressed. The recorder is operable over a temperature range of 0°C to 50°C, with a timing error of less than ±.05% of the 99.99-min full-scale timing range. Periods longer than 99.99 min can be monitored, provided the return to zero of the timer is noted and taken into consideration.