Alcohol and estrogen replacement therapy in postmenopausal women. Direct and mediated effects on cognitive component processes.

The literature remains contentious regarding the separate and combined effects of moderate drinking and estrogen replacement therapy (ERT) on cognition. In the current study, the authors sought to disentangle the predictive utility of alcohol use, ERT and their interaction on the episodic and semantic memory stores of postmenopausal women. It was predicted that relationships between moderate drinking, ERT and cognition would be attenuated by demographic and health-related factors. Postmenopausal women (n = 298) completed a battery of cognitive tests designed to assess speed and accuracy of episodic and knowledge-based cognitive processing. Potentially confounding variables were categorized and tested as mediators in hierarchical regression analyses. Moderate drinking was a weak predictor of episodic availability prior to removal of potential mediators. ERT use was a significant predictor of episodic and knowledge-based availability; no mediators were identified. Alcohol moderated ERT, as a combined alcohol/ERT variable was shown to be related to cognition. Neither moderate drinking nor ERT use was associated with cognitive speed. These findings suggest that positive relationships between alcohol and cognition are likely mediated by other variables, and should not be regarded as a benefit of drinking. Further, results support ERT as a predictor of knowledge-based and episodic availability, independent of mood stabilization or socioeconomic influences. Finally, alcohol and ERT appear to interact to impact both episodic and knowledge-based performance.

Alcohol, neurotransmitter systems, and behavior.

Alcohol affects several neurotransmitter systems within the brain. In this article, the author describes its effects on 5 major ones: glutamate, gamma-amino-butyric acid (GABA), dopamine, serotonin, and opioid systems. The author also notes the interactions and interdependencies of these transmitters, and provides details on both immediate effects and long-term adaptations. Last, the author explains several psychopharmacological treatments for alcoholism and the effects of these treatments on transmitters, and draws conclusions.

Efficiency of visual selective attention is related to the type of target.

Lavie and Cox (1997, Psychological Science, 8, 395) suggested that stimuli outside the focus of attention can have more distracting effects when the task requires less attention than when it requires more. This idea provides an explanation for the proposed dissociation found between two forms of attentional control (Folk & Remington, 1998, Journal of Experimental Psychology: Human Perception and Performance, 24, 847). This proposal was based on a red (green) distractor that captured attention when a red (green) target was used, but not when a green (red) target was used, and the further result that, if there were no distractor, reaction times were faster than with either type of distractor. We tested whether a target that requires serial search would eliminate the dissociation. With the same targets used by Folk and Remington (ones that can be found with parallel search), we also obtained a dissociation. However, with the serial-search targets, dissociation was not found. Our interpretation is that the dissociation represents two forms of the same attentional process.

Duration Ratings as an Index of Processing Resources Required for Cognitive Tasks.

Six experiments provided tests of the effectiveness of subjective duration ratings as an index of the processing resources required in cognitive tasks. Duration ratings reflected significant differences between the resources needed to process high- and low-frequency words (Experiments 1, 5, and 6), and ambiguous and unambiguous words (Experiments 1 and 2), and produced an interaction between memory load and word frequency (Experiment 6). However, participants tended to assign higher ratings to larger stimuli (Experiments 1, 4, and 5); for example, words in upper case received higher ratings than words in lower case. Although physical size of stimuli is an important factor to consider, subjective duration estimates provide a useful measure for understanding cognitive processing. This conclusion is supported by the current replication of several findings in the cognitive literature, including the word-frequency and lexical-ambiguity effects.