The adaptive effect of personal control when facing breast cancer: Cognitive and behavioural mediators

This prospective study examines the cognitive and behavioural mediators of the relation between personal control and the initial response to a breast cancer diagnosis as well as subsequent psychological adjustment. A total of 143 patients participated immediately after diagnosis (T1), after surgery (T2) and 2 months after the end of treatment (T3), of whom 92 also completed a questionnaire pre-diagnosis (T0). The buffering effect of personal control on psychological distress shortly after diagnosis was mediated by cancer-specific cognitions, i.e. threat appraisal and coping self-efficacy. Moreover, a strong sense of personal control predicted lower levels of anxiety 2 months after the end of treatment, but was unrelated to distress at T3. The adaptive effect on anxiety was mediated by threat appraisal and active engagement in social life after surgery, but not by active patient participation or coping self-efficacy. These results confirm and explain the adaptive effect of control. Apparently, women with a low sense of control appraise cancer and their personal coping skills more negatively, which makes them vulnerable to distress in response to diagnosis. Furthermore, women with a strong sense of control might regulate anxiety by remaining engaged in social life.     

Divided stimulus control: a replication and a quantitative model

Four pigeons were trained on a conditional discrimination. The conditional stimuli were compounds of pairs of stimuli from two different dimensions, fast versus slow cycles of red or green stimuli, and short- versus long-duration presentations of these cycles. Across conditions, the probability of reinforcers for correctly responding to each dimension was varied from 0 to 1. Discriminability, measured by log d, for stimuli on a dimension increased as the relative frequency of reinforcers for that dimension increased, replicating the results of Shahan and Podlesnik (2006). Two further conditions showed that discriminability between stimuli on each dimension was unaffected by whether the stimuli on the other dimension varied or were constant. Finally, maximal discriminability was unchanged in a redundant-relevant cues condition in which either of the stimuli comprising a compound signaled the same correct response. Davison and Nevin's (1999) model provided an excellent quantitative account of the effect of relative reinforcer frequency on discriminability, and thus of the way in which divided stimulus control is itself controlled by relative reinforcement.     

The identities hidden in the matching laws, and their uses

Various theoretical equations have been proposed to predict response rate as a function of the rate of reinforcement. If both the rate and probability of reinforcement are considered, a simple identity, defining equation, or "law" holds. This identity places algebraic constraints on the allowable forms of our mathematical models and can help identify the referents for certain empirical or theoretical coefficients. This identity can be applied to both single and compound schedules of reinforcement, absolute and relative measures, and to local, global and overall rates and probabilities. The rate matching equations of Hernstein and Catania appear to have been approximations to, and to have been evolving toward, one form of this algebraic identity. Estimates of the bias and sensitivity terms in the generalized ratio and logarithmic matching models are here held to be averaging artifacts arising from fitting procedures applied to models that violate or conceal the underlying identities.     

聚焦词素语义加工的时间轴——先形后义还是形义并行?

目前学术界在词素的认知加工这一问题上存在两种观点.“先形后义”激活论认为词素加工首先经历词形分离,然后才能激活词素语义;“形义并行”激活论则认为上述两种加工同时发生.它们争论的焦点在于词素语义加工发生的阶段.“先形后义”有两种可能:词素形、义激活均发生于前词汇阶段,但形的激活发生更早些;或词素形的激活发生在前词汇阶段,而义的激活发生在后词汇阶段.“形义并行”则只有一种可能:词素形与义在前词汇阶段同时得到激活.两派观点均有相应的实证和理论支持(前词汇和后词汇模型).未来研究需解决研究范式及理论发展方面的问题.     

注意和非注意条件下的整体和局部性质加工

以往关于整体和局部知觉的研究通常要求被试直接对出现在复合刺激整体或局部水平上的靶目标做反应,因此复合刺激与任务相关并被注意。该研究通过测量复合字母的整体和局部性质对随后出现的探测刺激的启动效应来研究在非注意条件下整体和局部性质加工的差异。实验一发现复合刺激的整体和局部性质对探测刺激产生负启动效应,但二者没有显著差异。实验二缩短了启动刺激与探测刺激之间的时间间隔,复合刺激的整体和局部性质对探测刺激都不再产生启动效应。在实验一、二中,当要求被试直接对复合刺激做反应时,其分辨局部性质的错误率都比分辨整体性质的错误率高。根据这些结果,讨论了在注意和非注意下的整体和局部性质加工的差异。     

大脑两半球与整体和局部性质的选择性加工

研究大脑两半球在加工整体和局部性质中的优势以及两半球能否同时分别选择两个复合刺激的整体和局部性质。实验中把一个复合字母随机呈现在左视野或右视野,或者把两个复合字母同时分别呈现在左视野和右视野。实验一发现,在单侧呈现条件下,被试检测左右视野的整体或局部靶目标的反应时没有显著差别,但在双侧同时呈现条件下,检测右视野局部靶目标比检测左视野局部靶目标时的反应时短。实验二要求被试检测同时呈现在左右视野的整体或局部靶目标,发现当两个视野的靶目标处于同一水平时(整体或局部)反应时较短,两个视野的靶目标处于不同水平时(一侧处于整体水平而另一侧处于局部水平)反应时较长。这些结果提示,当两个复合刺激同时呈现在左右视野时,大脑左半球在选择性加工局部性质时具有优势;左右两半球更容易选择两个复合刺激同一个水平的性质,分别选择两个复合刺激不同水平的性质比较困难。     

关于过度医疗的经济学分析与伦理

近年来,过度医疗问题引起医学伦理学界的普遍关注。过度医疗不仅是一个伦理问题,同时也是一种经济现象。过度医疗的经济学表现是医生诱导需求,直接成因是缺乏弹性的医疗需求,存在的市场环境是垄断竞争。遏止过度医疗需采取相应的伦理与经济对策。