Temporal proximity and reinforcement sensitivity in multiple schedules

Distributions of reinforcers between two components of multiple variable-interval schedules were varied over a number of conditions. Sensitivity to reinforcement, measured by the exponent of the power function relating ratios of responses in the two components to ratios of reinforcers obtained in the components, did not differ between conditions with 15-s or 60-s component durations. The failure to demonstrate the “short-component effect,” where sensitivity is high for short components, was consistent with reanalysis of previous data. With 60-s components, sensitivity to reinforcement decreased systematically with time since component alternation, and was higher in the first 15-s subinterval of the 60-s component than for the component whose total duration was 15 s. Varying component duration and sampling behavior at different times since component transition may not be equivalent ways of examining the effects of average temporal distance between components.     

Choice between reliable and unreliable outcomes: mixed percentage-reinforcement in concurrent chains.

Pigeons' choices between alternatives that provided different percentages of reinforcement in mixed schedules were studied using the concurrent-chains procedure. In Experiment 1, the alternatives were terminal-link schedules that were equal in delay and magnitude of reinforcement, but that provided different percentages of reinforcement, with one schedule providing, reinforcement twice as reliably as the other. All pigeons preferred the more reliable schedule, and their level of preference was not systematically affected by variation in the absolute percentage values, or in the magnitude of reinforcement. In Experiment 2, preference for a schedule providing 100% reinforcement over one providing 33% reinforcement increased systematically with increases in the duration of the terminal links. In contrast, preference decreased systematically with increases in the duration of the initial links. Experiment 3 examined choice with equal percentages of reinforcement but unequal delays to reinforcement. Preference for the shorter delay to reinforcement was not systematically affected by variation in the absolute percentage of reinforcement. The overall pattern of results supported predictions based on an extension of the delay-reduction hypothesis to choice procedures involving mixed schedules of percentage reinforcement.     

Dark adaptation of foveal cones during the cone-plateau period

Following substantial bleaching by "white" light, absolute threshold, relative spectral sensitivity and sensation of hue of monochromatic lights were measured at the central fovea during the cone-plateau period. The absolute-threshold level was found to increase and then decrease markedly, the relative spectral sensitivity remained invariant, while the sensation of hues of monochromatic lights from the long- and middle-wave regions of the spectrum changed toward hues of shorter wavelengths.     

The holocaust of first nation people: Residual effects on parenting and treatment implications

The residential school experience was devastating for many First Nation (Indian) people. The lingering effects of this era have been far reaching and remain painfully evident throughout Native communities. One of the more obvious areas directly affected has been parenting. This paper discusses current parenting difficulties of Native clients who were formerly in residential schools. A connection is made between the abuse experienced by these individuals and their parental struggles. Along with addressing various sociopolitical issues, a number of clinical interventions designed to promote the healing process of these victims and their families are provided and discussed.     

The medial amygdala: Serotonergic inhibition of shock-lnduced aggression and pain sensitivity in rats

Two aspects of the amygdaloid complex (corticomedial and basolateral) were examined with reference to serotonergic inhibition of shock-induced aggression. Fighting was significantly depressed by serotonergic stimulation (5-HT, 10 μg bilateral) in the corticomedial amygdala while serotonergic blockade (methysergide, 5 μg bilateral) in this region increased levels of fighting. No consistent effects were obtained with serotonergic manipulation of the basolateral amygdala. Further investigation revealed that the state of serotonergic activity in medial amygdaloid sites was associated with concomitant alterations in the animals' sensitivity to footshock. Results are discussed in relation to a) a general inhibitory role of serotonin in behavioural mechanisms and b) a dopaminergic-serotonergic balance for behavioural arousal involving medial amygdaloid nuclei.     

Assessment of Disgust Sensitivity in Children With an Age-Downward Version of the Disgust Emotion Scale

The present study examined the psychometric properties of the Disgust Emotion Scale for Children (DES-C). Principal components analysis of the DES-C data revealed five factors reflecting disgust toward (a) rotting foods, (b) injection and blood, (c) odors, (d) mutilation and death, and (e) animals, which were largely in keeping with the intended subscales. The DES-C showed good reliability, excellent convergent validity (as established by correlations with an alternative self-report index of disgust), fairly good predictive validity (as assessed by correlations with measures of fear/anxiety and a behavioral index of disgust), and acceptable parent–child agreement (in particular with the mothers). Importantly, the DES-C proved to perform better on some psychometric indicators than an age-downward version of the Disgust Scale. These findings indicate that the DES-C should be regarded as the preferred scale for measuring disgust sensitivity and its role in the etiology and maintenance of anxiety problems in children.     

拟人的品牌更环保?拟人化沟通对促进绿色消费倾向的影响

越来越多的企业采用品牌拟人化沟通的方式进行品牌传播, 促进绿色消费倾向。本研究将基于习得可评估性理论, 探索品牌拟人化沟通对绿色消费倾向的影响机制及边界条件。本研究共包含4个实验。实验1表明品牌拟人化沟通能够有效促进绿色消费倾向, 构建了从品牌拟人化沟通到习得可评估性到品牌环保价值敏感性再到绿色消费倾向的完整因果链。实验2界定主效应的边界, 发现相比于普通品牌, 主效应在绿色品牌情境中更显著, 再次验证主效应的理论逻辑。实验3分析了消费者动机类型(利己/利他)对主效应的调节作用。结果表明,当消费者利他动机被激发时, 品牌拟人化沟通能够显著地促进绿色消费倾向, 当消费者利己动机被激发时, 品牌拟人化沟通不会影响绿色消费倾向。实验4验证了产品类型(搜索品/体验品)对主效应的调节作用。结果表明当产品类型为搜索品时,品牌拟人化沟通能够显著地促进绿色消费倾向, 当产品类型为体验品时, 品牌拟人化沟通不会影响绿色消费倾向。本研究拓展了品牌拟人化沟通以及绿色消费相关领域的研究。