Serum β-Amyloid Correlates with Neuropsychological Impairment

ABSTRACT

Aims: Evidence suggests a relationship between peripheral Aβ and AD. We hypothesized that higher levels of serum Aβ_1–42 would be associated with memory impairment, thought to occur early in the disease, and rises in serum Aβ_1–40, which occur later, would be associated with impairment in non-memory measures. Methods: Using a cross-sectional design, we examined the relationship of serum Aβ_1–40, Aβ_1–42, and the ratio of Aβ_{1–42/1–40} to neuropsychological measures in 40 cognitively normal controls, 13 MCI subjects, and 25 AD patients. Results: Serum Aβ_1–42 and the ratio of Aβ_{1–42/1–40} were significantly higher in the MCI group compared to the controls. A significant relationship in the hypothesized direction (poorer scores associated with higher Aβ_1–40 serum levels) was found between Aβ_1–40 and measures of executive functions across the entire cohort of individuals tested and with measures of language and processing speed in the AD group. Regression analysis found that neuropsychological measures accounted for 26% of the variance in serum Aβ_1–40, in the MCI/AD but not the controls. Furthermore that language and executive measures were significant predictors. Conclusions: Results provide preliminary data to partially support our hypotheses and suggest that changes in serum Aβ levels may be attributed to pathological changes within the brain.     

Higher-order activity beyond the word level: cortical dynamics of simple transitive sentence comprehension

Slow electrophysiological effects, which fluctuate throughout the course of a sentence, independent of transient responses to individual words, have been reported. However, this type of activity has scarcely been studied, and with only limited use of electrophysiological information, so that the brain areas in which these variations originate have not been clearly identified. To improve this state of affairs, a principal component analysis and a modern source analysis algorithm (LORETA) were applied to the slow activity underlying transitive sentence reading. Four components explained 97.3% of the variance. Of key interest was a slow variation that occurred throughout the entire sentence but peaked with the appearance of the verb. The main solution for this component was localized in prefrontal and temporal regions presumably involved in semantic sentence processing. This constitutes empirical evidence for cortical activity--related to semantic processes thought to be involved in thematic role assignment--developing throughout the sentence but presenting a conspicuous maximum with the appearance of the verb. This finding also highlights the central role of verb information in the understanding of transitive sentences.     

Goal orientations, motivational climate, equality, and discipline of Spanish physical education students

This study analyzes how dispositional goal orientations and perception of different motivational climates are related to the students' perception of sex-related egalitarian treatment and the appearance of disciplined or undisciplined behaviors in physical education classes. Analyses showed that ego orientation is a predictor of undisciplined behavior. Task orientation was positively associated to discipline. The perception of task-involving motivational climate is related to the students' perception of equal treatment. On the contrary, the perception of ego-involving climate has been linked positively to the prediction of the perception of sex discrimination in physical education classes and negatively to the perception of equality and the appearance of disciplined behavior. This study discusses the implications of these results related to teaching instructional actions in physical education classes.     

Mismatch between what is expected and what actually occurs triggers memory reconsolidation or extinction

In previous experiments on contextual memory, we proposed that the unreinforced re-exposure to the learning context (conditioned stimulus, CS) acts as a switch guiding the memory course toward reconsolidation or extinction, depending on reminder duration. This proposal implies that the system computes the total exposure time to the context, from CS onset to CS offset, and therefore, that the reminder presentation must be terminated for the switching mechanism to become operative. Here we investigated to what extent this requirement is necessary, and we explored the relation between diverse phases in the reconsolidation and extinction processes. We used the contextual memory model of the crab Chasmagnathus which involves an association between the learning context (CS) and a visual danger stimulus (unconditioned stimulus, US). Administration of cycloheximide was used to test the lability state of memory at different time points. The results show that two factors, no-reinforcement during the reminder (i.e., CS re-exposure) and CS offset are the necessary conditions for both processes to occur. Regardless of the reminder duration, memory retrieved by unreinforced CS re-exposure emerges intact and consolidated when tested before CS offset, suggesting that neither reconsolidation nor extinction is concomitant with CS re-exposure. Either process could only be triggered once the definitive mismatch between CS and US is confirmed by CS termination without the expected reinforcement.     

The Multi-Center Dilemma Project: an investigation on the role of cognitive conflicts in health

The Multi-Center Dilemma Project is a collaborative research endeavour aimed at determining the role of dilemmas--a kind of cognitive conflict, detected by using an adaptation of Kelly's Repertory Grid Technique--in a variety of clinical conditions. Implicative dilemmas appear in one third of the non-clinical group (n = 321) and in about half of the clinical group (n = 286), the latter having a proportion of dilemmas that doubles that of the non-clinical sample. Within the clinical group, we studied 87 subjects, after completing a psychotherapy process, and found that therapy helps to dissolve those dilemmas. We also studied, independently, a group of subjects diagnosed with social phobia (n = 13) and a group diagnosed with irritable bowel syndrome (n = 13) in comparison to non-clinical groups. In both health related problems, dilemmas seem to be quite relevant. Altogether, these studies, though preliminary (and with a small group size in some cases), yield a promising perspective to the unexplored area of the role of cognitive conflicts as an issue to consider when trying to understand some clinical conditions, as well as a focus to be dealt with in psychotherapy when dilemmas are identified.     

Nursing Motives for Helping Scale (N-MHS): reliability and validity

This paper presents the Nursing Motives for Helping Scale (N-MHS), an instrument designed for the evaluation of three of the four motives for helping derived from Batson's helping pathway theory. Dimensionality was analyzed by means of principal component analysis (n = 113), followed by confirmatory factor analysis. A 3-factor structure (corresponding to Batson's differentiation among altruistic motivation, reward-seeking motivation, and punishment-avoidance motivation, respectively), with 9 items distributed in three latent variables, revealed an acceptable fit to the data. Alpha values (.60 - .74) showed that internal consistency was acceptable for a newly developed subscale with a small number of items. Convergence validity was evaluated with correlations between N-MHS subscales scores and scores on the Professional Expectations Scale (Garrosa, Moreno-Jiménez, Rodríguez-Carvajal, and Morante, 2005). The three resulting subscales are a promising instrument for the evaluation of three nursing motives for helping that can contribute to reduce the potential risks and to improve the potential benefits both for the nurse and the patient.     

Null sex differences in general intelligence: evidence from the WAIS-III

There is an increasing number of studies claiming that the sex differences in general intelligence are "real." The empirical evidence is based on the summation of the standardized sex differences in several cognitive batteries. However, the scientific construct of general ability rests on the correlations among test scores, rather than on their summation. The latter (ability in general) is an arbitrary variable, not a scientific construct. General ability is not a function of any particular cognitive test, but a source of variance evidenced by the correlation between several diverse tests, each of which reflects general ability (g) to some extent, but also group factors and test specificity. Because there are important educational, economic, and social consequences of a group difference in general ability, it is especially germane to evaluate the possibility of an average sex difference in its proxy measures, such as IQ. The Spanish standardization of the WAIS-III is analyzed in the present study. The sample was made up of 703 females and 666 males, aged 15-94, drawn as a representative sample of the population in terms of educational level and geographical location. Although a male advantage of 3.6 IQ points is observed, the difference is in "ability in general," not in "general ability" (g). Given that the main ingredient of the strong association between IQ and a broad range of social correlates is g, and given that there is no sex difference in g, then the average IQ sex-difference favoring males must be attributed to specific group factors and test specificity.