The interaction of temporal generalization gradients predicts the context effect

In a temporal double bisection task, animals learn two discriminations. In the presence of Red and Green keys, responses to Red are reinforced after 1-s samples and responses to Green are reinforced after 4-s samples; in the presence of Blue and Yellow keys, responses to Blue are reinforced after 4-s samples and responses to Yellow are reinforced after 16-s samples. Subsequently, given a choice between Green and Blue, the probability of choosing Green increases with the sample duration-the context effect. In the present study we asked whether this effect could be predicted from the stimulus generalization gradients induced by the two basic discriminations. Six pigeons learned to peck Green following 4-s samples (S(+)) but not following 1-s samples (S(-)) and to peck Red following 4-s samples (S(+)) but not following 16-s samples (S(-)). Temporal generalization gradients for Green and Red were then obtained. Finally, the pigeons were given a choice between Green and Red following sample durations ranging from 1 to 16 s. Results showed that a) the two generalization gradients had the minimum at the S(-) duration, an intermediate value between the S(-) and the S(+) durations, and the maximum at the S(+) as well as more extreme durations; b) on choice trials, preference for Green over Red increased with sample duration, the context effect; and c) the two generalization gradients predicted the average context effect well. The Learning-to-Time model accounts for the major trends in the data.     

License to sin: Self‐licensing as a mechanism underlying hedonic consumption

Hedonic overconsumption is often considered to be caused by impulsive factors. The current paper investigates whether self‐licensing, relying on reasons to justify subsequent gratification, can also be included as a significant contributor to hedonic consumption. Two studies were conducted to investigate whether self‐licensing can account for an increase in hedonic consumption while ruling out impulsive factors such as resource depletion, negative affect, and visceral state as alternative explanations. A pilot study indicated that perceiving oneself as having invested greater effort and thus having a self‐licensing cue did not lead to a decline in self‐control capacity compared with not having a self‐licensing cue. The main study employed the same procedure and established that having a licensing cue did lead to increased snack intake while controlling for impulsive factors. Together, these studies support the notion that self‐licensing is a separate mechanism leading to hedonic gratification independent of impulsive factors. Copyright © 2011 John Wiley & Sons, Ltd.     

The social costs of punishment

Lab experiments on punishment are of limited relevance for understanding cooperative behavior in the real world. In real interactions, punishment is not cheap, but the costs of punishment are of a different nature than in experiments. They do not correspond to direct payments or payoff deductions, but they arise from the repercussions punishment has on social networks and future interactions.     

Arm adductor with arm abduction in rotator cuff tear patients vs. healthy--design of a new measuring instrument

The incidence of (a)symptomatic rotator cuff tears is high, but etiologic mechanisms are unclear and treatment outcomes vary. A practical tool providing objective outcome measures and insight into etiology and potential patient subgroups is desirable. Symptomatic cuff tears coincide with humerus cranialization. Adductor co-activation during active arm abduction has been reported to reduce subacromial narrowing and pain in cuff patients. We present an easy-to-use method to evaluate adductor co-activation. Twenty healthy controls and twenty full-thickness cuff tear patients exerted EMG-recorded isometric arm abduction and adduction tasks. Ab- and adductor EMG's were expressed using the "Activation Ratio (AR)" (-1 ≤ AR ≤ 1), where lower values express more co-activation. Mean control AR's ranged from .7 to .9 with moderate to good test-retest reliability (ICC: .60-.74). Patients showed significantly more adductor co-activation during abduction, with adductor AR's ranging between .3 (teres major) and .5 (latissimus dorsi). In conclusion, the introduced method discriminates symptomatic cuff tear patients from healthy controls, quantifies adductor co-activation in an interpretable measure, and provides the opportunity to study correlations between muscle activation and humerus cranialization in a straightforward manner. It has potential as an objective outcome measure, for distinguishing symptomatic from asymptomatic cuff tears and as a tool for surgical or therapeutic decision-making.     

Career Adapt-Abilities Scale—Brazilian Form: Psychometric properties and relationships to personality

The Career Adapt-Abilities Scale—Brazilian Form (CAASBrazil) consists of four scales which measure concern, control, curiosity, and confidence as psychosocial resources for managing occupational transitions, developmental tasks, and work traumas. Internal consistency estimates for the subscale and total scores ranged from good to excellent. The factor structure was quite similar to the one computed for combined data from 13 countries. CAASBrazil is similar to the International Form, with the exception of two items that were not included in Brazilian version. Concurrent validity evidence was collected relative to personality factors from the Five-Factor Model of Personality. The relationships between career adaptability and personality factors were as predicted.     

Effect of an aerobic training program as complementary therapy in patients with moderate depression

The aim of this study was to assess the effects of an aerobic training program as complementary therapy in patients suffering from moderate depression. 82 female patients weredivided into a group that received traditional pharmacotherapy (Fluoxetine 20 mg) and a group that received pharmacotherapy plus an aerobic training program. This program was carried out for eight consecutive weeks, three days per week, and included gymnastics, dancing, and walking. Depressive symptoms were measured with the Beck Depression Inventory and the ICD-10 Guide for Depression Diagnosis, both administered before and after treatments. The results confirm the effectiveness of the aerobic training program as a complementary therapy to diminish depressive symptoms in patients suffering from moderate depression.     

Factor Analysis via Components Analysis

When the factor analysis model holds, component loadings are linear combinations of factor loadings, and vice versa. This interrelation permits us to define new optimization criteria and estimation methods for exploratory factor analysis. Although this article is primarily conceptual in nature, an illustrative example and a small simulation show the methodology to be promising.