Higher-Order Unification: A structural relation between Huet's method and the one based on explicit substitutions

We compare two different styles of Higher-Order Unification (HOU): the classical HOU algorithm of Huet for the simply typed λ-calculus and HOU based on the λσ-calculus of explicit substitutions. For doing so, first, the original Huet algorithm for the simply typed λ-calculus with names is adapted to the language of the λ-calculus in de Bruijn's notation, since this is the notation used by the λσ-calculus. Afterwards, we introduce a new structural notation called unification tree, which eases the presentation of the subgoals generated by Huet's algorithm and its behaviour. The unification tree notation will be important for the comparison between Huet's algorithm and unification in the λσ-calculus whose derivations are presented into a structure called derivation tree. We prove that there exists an important structural correspondence between Huet's HOU and the λσ-HOU method: for each (sub-)problem in the unification tree there exists a counterpart in the derivation tree. This allows us to conclude that the λσ-HOU is a generalization of Huet's algorithm and that solutions computed by the latter are always computed by the former method.     

Personal and workgroup incivility: impact on work and health outcomes

This article develops a theoretical model of the impact of workplace incivility on employees' occupational and psychological well-being. In Study 1, the authors tested the model on 1,158 employees, finding that satisfaction with work and supervisors, as well as mental health, partially mediated effects of personal incivility on turnover intentions and physical health; this process did not vary by gender. Study 2 cross-validated and extended these results on an independent sample of 271 employees, showing negative effects of workgroup incivility that emerged over and above the impact of personal incivility. In both studies, all results held while controlling for general job stress. Implications for organizational science and practice are discussed.     

A friend is a present you give to your “Self”: Avoidance of intimacy moderates the effects of friends on self-liking

The current research proposes that thinking about friends improves feelings about the self and does so differentially depending on avoidance of intimacy. Based on previous findings that individuals who avoid intimacy in relationships (avoidant individuals) contrast their self-concepts with primed friends whereas those who pursue intimacy in relationships (non-avoidant individuals) assimilate their self-concepts to primed friends [Gabriel, S., Carvallo, M., Dean, K., Tippin, B. D., & Renaud, J. (2005). How I see “Me” depends on how I see “We”: The role of avoidance of intimacy in social comparison. Personality and Social Psychology Bulletin, 31, 156-157], we predicted that friends who embody negative aspects of self would lead avoidant individuals to like themselves more, whereas friends who embody positive aspects of self would lead non-avoidant individuals to like themselves more. A pretest determined that good friends were seen as more similar to positive and ideal aspects of the self, whereas friends about whom participants had more mixed feelings (ambivalent friends) were seen as more similar to disliked and feared aspects of the self. Four experiments supported the main hypotheses. In Experiment 1, non-avoidant individuals like themselves more when good friends were primed. In Experiment 2, avoidant individuals like themselves more when ambivalent friends were primed. In Experiment 3, non-avoidant individuals liked themselves better after thinking about a friend’s positive traits, whereas avoidant individuals liked themselves better after thinking about a friend’s negative traits. In Experiment 4, all individuals under self-esteem threat strategically brought friends to mind who would help them like themselves more.     

Determinants of instrumental extinction in terrestrial toads (Bufo arenarum)

Previous research in a water-reinforced instrumental training situation with toads (Bufo arenarum) has shown that performance in both acquisition and extinction is poorer after partial, rather than continuous reinforcement training. In Experiment 1, the performance of a group receiving 24 trials on a 50% partial reinforcement schedule was poorer in acquisition and extinction than that of continuously reinforced groups matched for trials or reinforcements. However, partially reinforced toads extinguished at the same rapid rate as a continuously reinforced group that received training only on the days in which the partial toads received water reinforcement. In Experiment 2, extinction was faster after 10 reinforced acquisition trials than after 30 trials. This evidence suggests that the deleterious effects of partial reinforcement in toads can be explained by a combination of two factors, namely, the distribution of reinforced trials across days and the total number of reinforcements.     

Acute Stress Modulates Risk Taking in Financial Decision Making

ABSTRACT— People's decisions are often susceptible to various demands exerted by the environment, leading to stressful conditions. Although a goal for researchers is to elucidate stress-coping mechanisms to facilitate decision-making processes, it is important to first understand the interaction between the state created by a stressful environment and how decisions are performed in such environments. The objective of this experiment was to probe the impact of exposure to acute stress on financial decision making and examine the particular influence of stress on decisions with a positive or negative valence. Participants' choices exhibited a stronger reflection effect when participants were under stress than when they were in the no-stress control phase. This suggests that stress modulates risk taking, potentially exacerbating behavioral bias in subsequent decision making. Consistent with dual-process approaches, decision makers fall back on automatized reactions to risk under the influence of disruptive stress.     

Adult Attachment Orientations and College Student Distress: The Mediating Role of Problem Coping Styles

In this study, the authors examined relations among adult attachment orientations, maladaptive problem coping styles, and a composite measure of current distress within a sample of 55 undergraduates (17 men, 38 women). Results indicated that each adult attachment orientation and each problem coping style measure was related in expected directions to students' distress. In addition, problem coping styles largely mediated the impact of insecure adult attachment orientations on distress. Implications of our findings to advancing an attachment theory‐informed perspective on college student coping, distress, and intervention are discussed.     

Depersonalization: a selective impairment of self-awareness

Depersonalization is characterised by a profound disruption of self-awareness mainly characterised by feelings of disembodiment and subjective emotional numbing. It has been proposed that depersonalization is caused by a fronto-limbic (particularly anterior insula) suppressive mechanism--presumably mediated via attention--which manifests subjectively as emotional numbing, and disables the process by which perception and cognition normally become emotionally coloured, giving rise to a subjective feeling of 'unreality'. Our functional neuroimaging and psychophysiological studies support the above model and indicate that, compared with normal and clinical controls, DPD patients show increased prefrontal activation as well as reduced activation in insula/limbic-related areas to aversive, arousing emotional stimuli. Although a putative inhibitory mechanism on emotional processing might account for the emotional numbing and characteristic perceptual detachment, it is likely, as suggested by some studies, that parietal mechanisms underpin feelings of disembodiment and lack of agency feelings.     

Intracellular calcium chelation and pharmacological SERCA inhibition of Ca2+ pump in the insular cortex differentially affect taste aversive memory formation and retrieval

Variation in intracellular calcium concentration regulates the induction of long-term synaptic plasticity and is associated with a variety of memory/retrieval and learning paradigms. Accordingly, impaired calcium mobilization from internal deposits affects synaptic plasticity and cognition in the aged brain. During taste memory formation several proteins are modulated directly or indirectly by calcium, and recent evidence suggests the importance of calcium buffering and the role of intracellular calcium deposits during cognitive processes. Thus, the main goal of this research was to study the consequence of hampering changes in cytoplasmic calcium and inhibiting SERCA activity by BAPTA-AM and thapsigargin treatments, respectively, in the insular cortex during different stages of taste memory formation. Using conditioned taste aversion (CTA), we found differential effects of BAPTA-AM and thapsigargin infusions before and after gustatory stimulation, as well as during taste aversive memory consolidation; BAPTA-AM, but not thapsigargin, attenuates acquisition and/or consolidation of CTA, but neither compound affects taste aversive memory retrieval. These results point to the importance of intracellular calcium dynamics in the insular cortex during different stages of taste aversive memory formation.