Effects of extinction in multiple contexts on the renewal of associative tolerance to ethanol

The Pavlovian analysis of drug tolerance describes how the contexts of drug administration participate in the elicitation of compensatory conditioned responses that are, at least partly, responsible for tolerance. Findings indicate that if an association is acquired in one context and extinguished in another one, when exposing the subjects to the acquisition context, renewal of the conditioned response will take place. Ambiguous evidence exists about whether or not this effect diminishes when extinguishing the association in multiple contexts. This investigation evaluates the existence of the phenomenon of renewal of tolerance to ethanol, and whether it diminishes by the extinction in multiple contexts. Evidence of renewal of tolerance to ethanol in rats was found, but no diminution was observed when extinguishing in multiple contexts.     

Alcohol drinking parties and consumption of alcohol and other drugs in youth

The main aim of this paper is to analyze the relationships of involvement in the "botellon" (meetings of youth in public places to drink, chat, etc.) with alcohol/other drug abuse and vandalism in young people. A school survey was performed in centres of Compulsory Secondary School (E.S.O.), high school, professional training and University education in Lugo, NW Spain. The sample (aged 12 to 30) was split into three groups according to alcohol use and botellon involvement; drug abuse, drug-related problems and vandalism were assessed in each group. Results indicate that regular botellon attendants display more problems with alcohol and other drugs, as well as higher involvement in vandalism; this relationship is stronger among young students. The increase in adolescent risk associated with the practice of the botellon is explained by peer group pressure to use drugs and the greater accessibility of alcohol/other drugs in these contexts.     

Design and power analysis: n and confidence intervals of means

In this study, we analyzed the validity of the conventional 80% power. The minimal sample size and power needed to guarantee non-overlapping (1-alpha)% confidence intervals for population means were calculated. Several simulations indicate that the minimal power for two means (m = 2) to have non-overlapping CIs is .80, for (1-alpha) set to 95%. The minimal power becomes .86 for 99% CIs and .75 for 90% CIs. When multiple means are considered, the required minimal power increases considerably. This increase is even higher when the population means do not increase monotonically. Therefore, the often adopted criterion of a minimal power equal to .80 is not always adequate. Hence, to guarantee that the limits of the CIs do not overlap, most situations require a direct calculation of the minimum number of observations that should enter in a study.     

Development of a questionnaire to assess user satisfaction of a penal mediation program (CSM-P)

The aim of the present study is to elaborate an instrument (CSM-P), valid for victims and aggressors, to assess satisfaction of individuals participating in a penal mediation program (VOM). The instrument was administered to a sample of 213 subjects, randomly chosen from the pool of participants in a VOM program of Catalonian Justice Department. Data analysis of the questionnaire shows an internal consistency of .88 (Cronbach's alpha). The dimensionality of the questionnaire is structured in a single factor that accounts for 61.45% of the variance. The instrument has proven its utility for assessing the satisfaction of the participants in a penal mediation program. Validation of the instrument in similar populations should be performed and it should be adapted to other contexts where assessing user satisfaction in a mediation program is necessary.     

The easy-to-hard effect in human (Homo sapiens) and rat (Rattus norvegicus) auditory identification

The authors examined whether progressively training humans and rats to perform a difficult auditory identification task led to larger improvements than extensive training with highly similar sounds (the easy-to-hard effect). Practice improved humans' ability to distinguish sounds regardless of the training regimen. However, progressively trained subjects were more accurate and showed more generalization, despite significantly less training with the stimuli that were the most difficult to distinguish. Rats showed less capacity to improve with practice but still benefited from progressive training. These findings indicate that transitioning from an easier to a more difficult task during training can facilitate, and in some cases may be essential for, auditory perceptual learning. The results are not predicted by an explanation that assumes interaction of generalized excitation and inhibition but are consistent with a hierarchical account of perceptual learning in which the representational precision required to distinguish stimuli determines the mechanisms engaged during learning.     

归类不确定情境下特征预测的理性模型研究

探讨了Bayesian规则计算公式的具体含义,进而考察了归类不确定情境下的特征预测是否符合Bayesian规则.包括2个实验:实验1探讨保持类别内目标成员中预测特征的比例不变,而改变类别内所有成员中预测特征的比例是否影响特征预测.实验2探讨保持类别内目标成员中预测特征的比例不变,进一步扩大类别内所有成员中预测特征比例的差异是否会影响特征预测.结果表明: 类别内目标成员中预测特征的比例影响特征预测,而类别内所有成员中预测特征的比例不影响特征预测.据此,本研究认为,Murphy对Bayesian规则计算公式的含义理解有偏差,其由此提出的"单类说"值得商榷.     

传递性推理的认知与脑机制探讨

以抽象的内容作为实验材料,测定12名大学生在完成四种不同格式的传递性推理任务时的事件相关电位(ERP),探讨传递性推理过程的认知机制与脑内时程动态变化.结果发现,被试解决四种不同类型推理题目时的正确率和反应时差异均不显著;但是"谁最大"提问方式的正确率显著高于"谁最小"提问方式,另外,在任务类型①与④中"谁最大"提问方式的反应时显著短于"谁最小"提问方式.脑电数据结果表明,不同任务类型下,不同提问方式所诱发的ERP波形基本一致.空间表象模型与语言学模型都不能很好地解释以上结论,这似乎表明推理过程是很复杂的,人们往往会采用不同的信息加工策略来解决不同的推理问题,从而激活不同的大脑区域和神经通路.     

认知神经和神经心理角度的多重类别学习系统

归类是一项非常重要的认知技能,近十多年来归类的研究尤其关注类别学习的多重系统问题.本文回顾了近年来国外对类别学习的认知神经和神经心理研究,结果表明不同的类别学习任务下的学习机制和所依赖的神经生理基础是不同的,支持类别学习的多系统理论.