Survival of the partial reinforcement extinction effect after contextual shifts

The effects of contextual shifts on the partial reinforcement extinction effect (PREE) were studied in autoshaping with rats. Experiment 1 established that the two contexts used subsequently were easily discriminable and equally salient. In Experiment 2, independent groups of rats received acquisition training under partial reinforcement (PRF) or continuous reinforcement (CRF). Significant PREEs were observed whether extinction occurred in the same or in a different context. In Experiment 3, after PRF or CRF acquisition training, each group received extinction of the same conditioned stimulus in both the same and different contexts. PREEs were observed under both conditions, although extinction was accelerated after a contextual shift. These results were discussed in relation to the role of mediational states in the PREE.     

Fatigue biases the decoy effect in males but not females

Individuals often need to make critical decisions even when they are in a fatigued state. Mental fatigue may lead to increased susceptibility to distraction and poor information processing but it is unclear exactly how fatigue shapes individuals' decision‐making. We studied how mental fatigue influences sensitivity to contextual information, indexed as decoy bias. Mental fatigue was induced using a multi‐source interference task, and decoy bias was assessed using a gambling task, in 124 young adults. Results showed that mental fatigue increased decoy bias through enhanced perceptual salience of contextual cues, but only in males. The findings provide insight into a gender‐specific relationship between fatigue and poor judgments. This study extends the current literature on links between fatigue and poor decision‐making by documenting a possible mechanism of the association. The results may have practical implications for designing optimal working hours and safeguarding people from suboptimal decisions.     

Practice variability promotes an external focus of attention and enhances motor skill learning

Variability in practice has been shown to enhance motor skill learning. Benefits of practice variability have been attributed to motor schema formation (variable versus constant practice), or more effortful information processing (random versus blocked practice). We hypothesized that, among other mechanisms, greater practice variability might promote an external focus of attention on the intended movement effect, while less variability would be more conducive to a less effective internal focus on body movements. In Experiment 1, the learning of a throwing task was enhanced by variable versus constant practice, and variable group participants reported focusing more on the distance to the target (external focus), while constant group participants focused more on their posture (internal focus). In Experiment 2, golf putting was learned more effectively with a random compared with a blocked practice schedule. Furthermore, random group learners reported using a more effective distal external focus (i.e., distance to the target) to a greater extent, whereas blocked group participants used a less effective proximal focus (i.e., putter) more often. While attentional focus was assessed through questionnaires in the first two experiments, learners in Experiment 3 were asked to report their current attentional focus at any time during practice. Again, the learning of a throwing task was more effective after random relative to blocked practice. Also, random practice learners reported using more external focus cues, while in blocked practice participants used more internal focus cues. The findings suggest that the attentional foci induced by different practice schedules might be at least partially responsible for the learning differences.     

Temporary inactivation of dorsal hippocampus attenuates explicitly nonspatial, unimodal, contextual fear conditioning

The current study examined the effects of temporary inactivation of the DH on freezing, rearing, ambulating, grooming, and whisking behavior in an explicitly nonspatial contextual fear conditioning paradigm in which olfactory stimuli served as temporally and spatially diffuse contexts. Prior either to training, testing, or both, male Sprague–Dawley rats received bilateral microinfusions of saline or the GABA_A agonist muscimol into the DH. Results indicate that temporary inactivation of DH produced both anterograde and retrograde deficits in contextually conditioned freezing, while sparing the acquisition and expression of freezing to a discrete auditory or olfactory CS. These data suggest that there is a decidedly nonspatial component to the role of DH in contextual conditioning, and that olfactory contextual conditioning is a fruitful means of further exploring this function.     

青少年自伤网络展示的动机及其影响

自我伤害行为是一种复杂且危险的心理病理行为,它会给个体的身心带来不同程度的损害。自伤是在多种因素的共同作用下产生,且在青少年中发生率最高。随着互联网的普遍使用,网络已经成为青少年生活中不可或缺的部分,近年来研究者开始关注到青少年的自伤网络展示行为。研究显示,许多自伤青少年会在网络上展示自己的自伤行为;个体一般是在多种动机的作用下对自己的自伤行为或经历进行展示;这些展示的内容既可能会让更多的人模仿或强化自伤,也可能会为自伤者提供社会支持,有助于他们减少自伤行为。     

The Usefulness of the Lutheran Confessions in the African World

Abstract: The Malagasy Lutheran Church is one of the fastest growing churches in Africa. Maturing after having been seeded by Western missionaries, the confessional bond to Lutheran history is flowering differently within (1) the development of African contextual theologies and (2) ecumenical dynamics involving Lutherans and other Christian traditions.     

Reducing chronic anxiety by making the threatening event predictable: An experimental approach

Panic disorder is characterized by both specific, phased fear and generalized, chronic anxiety. Standard extinction procedures are efficient in reducing specific fear. However, methods based on human conditioning research - that are capable of reducing chronic anxiety have not yet been thoroughly investigated. This study evaluates a new way of reducing chronic anxiety by signaling aversive events (or by making them more predictable). Using an experimental approach with healthy participants, specific fear and chronic anxiety were operationalized in a within-subjects fear-potentiated startle paradigm by, respectively, conditioning to a cue by presenting predictable shocks and conditioning to a context induced by unpredictable shocks. The results clearly demonstrate that context conditioning is reduced when a discrete cue is added that predicts the onset of the aversive event. The data suggest that making unpredictable events, such as for example panic attacks, predictable, may reduce the generalized and sustained anxiety that often complicates exposure treatment.     

Brain mechanisms associated with background monitoring of the environment for potentially significant sensory events

Background monitoring is a necessary prerequisite to detect unexpected changes in the environment, while being involved in a primary task. Here, we used fMRI to investigate the neural mechanisms that underlie adaptive goal-directed behavior in a cued task switching paradigm during real response conflict or, more generally, when expectations on the repetitive features of the environment were violated. Unexpected changes in sensory stimulus attributes in the currently unattended stimulus dimension thereby led to activations in a bilateral network comprising inferior lateral frontal, intraparietal, and posterior medial frontal brain regions, independent of whether these attributes elicited a factual response conflict or not. This fronto-parietal network may thus play an important role in adaptive responding to potentially significant events outside the current focus of attention.     

ERPs and contextual semantic discrimination: degrees of congruence in wakefulness and sleep

This study explores whether the brain can discriminate degrees of semantic congruency during wakefulness and sleep. Experiment 1 was conducted during wakefulness to test degrees of congruency by means of N400 amplitude. In Experiment 2, the same paradigm was applied to a different group of participants during natural night sleep. Stimuli were 108 sentences (definitions with two attributes) with four possible degrees of congruence as ending targets. In both studies, the amplitude of N400-like effect showed modulation according to the degree of congruency. The results indicate that the brain can accomplish sentential semantic discriminations not only in wakefulness but also in sleep.     

A prospective study of pressures from parents, peers, and the media on extreme weight change behaviors among adolescent boys and girls

The current study was designed to evaluate the role of sociocultural influences over a 16 month period on strategies to lose weight, extreme weight loss strategies, and strategies to increase muscles among adolescent boys (n=344) and girls (n=246). All participants completed measures of body dissatisfaction, body image importance, strategies to lose weight, extreme weight loss strategies, and strategies to increase muscles. Measures of perceived pressure to lose weight or increase muscles from mother, father, best male friend, best female friend and the media were also evaluated. Data were gathered on three occasions, 8 months apart. The results demonstrated that boys showed a decrease in strategies to lose weight and increase muscles over time, whereas girls showed an increase. Both boys and girls showed an increase in extreme weight loss strategies with girls demonstrating a greater increase than boys. The sociocultural influences generally were perceived by girls to relate to messages to lose weight, whereas for boys they were perceived to relate to increasing muscles. Messages from parents, particularly fathers, were strong predictors of both strategies to lose weight and increase muscles among boys, with the media and best male friend playing a limited role. For girls, the strongest influences were mothers and best female friends, with few influences from fathers or the media. The results of this study are discussed in terms of the importance of the various sociocultural influences in shaping body change strategies among young adolescent boys and girls, and the implications of these findings for intervention programs for adolescents.