"Brain-Specific" Nutrients: A Memory Cure?

Contents:
Nootropics, the Aging Brain, and Neural Bases of Learning and Memory, p.13
Phosphatidylserine, p.16
Choline, p.23
Piracetam, p.24
Vinpocetine, p.26
Acetyl-L-Carnitine, p.28
Antioxidants, p.30
Future Work and More Fine-Grained Analyses of Memory, p.32
Summary and Concluding Remarks, p.34     

The stability of validity coefficients over time: Ackerman's (1988) model and the general aptitude test battery

This study examined P. L. Ackerman's (1988) model of skill acquisition within an applied setting. Differences were examined between jobs on the basis of task consistency: changes in performance variability across experience, learning curves, and stability of ability-performance correlations across experience. Results showed the degree of task consistency influenced the shape of learning curves, with jobs composed of primarily consistent tasks improving more rapidly and reaching asymptote sooner. In addition, trends in ability-performance correlations were moderated by the degree of task consistency within ajob. Specifically, forjobs with primarily consistent tasks, general cognitive ability best predicted early performance whereas psychomotor ability best predicted later performance. In contrast, general cognitive ability was the strongest predictor across experience for jobs with primarily inconsistent tasks.     

What is minimal about predictive inferences?

Pronunciation of a probe word that relates to a highly predictable event is typically facilitated when the probe immediately follows the target sentence, but not when it is delayed until after a second sentence. These findings suggest that inferences about highly predictable events are minimally drawn during reading. Using a similar paradigm, in which the probe was delayed, we found significant priming in a reading condition that encouraged focus on the referential state of affairs (situation level) expressed in the sentences. In contrast, significant priming forpredictive texts was not observed in a reading condition that encouraged focus on the text per se (text level). These results are interpreted within a theoretical model that assumes that predictive inferences are represented at a situational level only, whereas explicitly presented information is represented at several levels (text and situational). It is in this sense that predictive inferences may be said to be minimally represented.     

The bizarreness effect: dissociation between item and source memory

The present study investigated the relationship between memory for particular items (nouns embedded in sentences) varying in bizarreness and the spatial location in which they were learned. Consistent with earlier findings, the items embedded in bizarre sentences were better recalled than those embedded in common sentences. This mnemonic advantage for bizarre sentences did not extend to memory for source (spatial location), which did not reliably vary as a function of bizarreness. This pattern is inconsistent with several existing theoretical formulations of the relation between item and source encoding and related findings. We propose a theoretical possibility for integrating these varied findings. Finally, the expectation-violation explanation of the bizarreness effect was not supported by the absence of a relation between recall of the items and memory for context.     

Suppression of sourness: a comparative study involving mixtures of organic acids and sugars

The degree of sourness suppression of perceptually equisour levels of citric, lactic, and malic acids by equal molar and weight amounts of sucrose, fructose, and glucose was determined in binary mixtures. Equisour acid levels were obtained by magnitude estimation. Mixture intensity ratings were collected on a categorical scale, using trained panelists. In general, equal sugar molarities and weights did not effect equivalent suppression. Instead, the perceived intensity of the sugars appeared to suppress sourness more systematically, implying that dominantly central neural mechanisms underlie suppression. This was confirmed when no significant differences were found between the suppressive abilities of sweetness-matched levels of sucrose, fructose, and an equiratio mixture of the two on citric acid sourness. The possibility of a separate receptor site/mechanism for glucose and a small peripheral component to suppression is also suggested.     

Importance effects on performance in event-based prospective memory tasks

In the present study we manipulated the importance of performing two event-based prospective memory tasks. In Experiment 1, the event-based task was assumed to rely on relatively automatic processes, whereas in Experiment 2 the event-based task was assumed to rely on a more demanding monitoring process. In contrast to the first experiment, the second experiment showed that importance had a positive effect on prospective memory performance. In addition, the occurrence of an importance effect on prospective memory performance seemed to be mainly due to the features of the prospective memory task itself, and not to the characteristics of the ongoing tasks that only influenced the size of the importance effect. The results suggest that importance instructions may improve prospective memory if the prospective task requires the strategic allocation of attentional monitoring resources.     

A reexamination of black-white mean differences in work performance: more data, more moderators

This study is the largest meta-analysis to date of Black-White mean differences in work performance. The authors examined several moderators not addressed in previous research. Findings indicate that mean racial differences in performance favor Whites (d = 0.27). Effect sizes were most strongly moderated by criterion type and the cognitive loading of criteria, whereas data source and measurement level were influential moderators to a lesser extent. Greater mean differences were found for highly cognitively loaded criteria, data reported in unpublished sources, and for performance measures consisting of multiple item scales. On the basis of these findings, the authors hypothesize several potential determinants of mean racial differences in job performance.     

A meta-analysis of the antecedents and consequences of pay level satisfaction

This study reports results from a meta-analysis of 28 correlates of pay level satisfaction involving 240 samples from 203 studies conducted over the past 35 years. Results are presented in 4 categories: primary determinants, antecedents, correlates, and outcomes of pay satisfaction. The authors controlled for pay in examining relations between correlates and pay level satisfaction, as suggested by theory and when primary studies were available to do so. The authors found support for many of the relations suggested by a theoretical model and also note some limitations in the research that has tested this model. The authors recommend changes and additions to the model and suggest additional primary research in specific areas.     

Forgetting of intentions in demanding situations is rapid

Demanding work settings often require the deferral of intended actions. In 3 experiments, participants were to withhold a response until they encountered a task change (which occurred 5, 15, or 40 sec later). To approximate highly demanding settings, the experimenters sometimes divided attention during the delay period. During some of the delays the experimenters interrupted the participants with an additional task (Experiment 1). Demanding conditions as well as interruptions revealed rapid forgetting of intentions at levels that would be considered significant in applied settings. Experiments 2 and 3 showed that this rapid forgetting was not reduced by strategic rehearsal and implementation intention strategies. The results suggest that maintaining intentions over brief delays is not a trivial task for the human cognitive system.