Lambda Calculus and Intuitionistic Linear Logic

The introduction of Linear Logic extends the Curry-Howard Isomorphism to intensional aspects of the typed functional programming. In particular, every formula of Linear Logic tells whether the term it is a type for, can be either erased/duplicated or not, during a computation. So, Linear Logic can be seen as a model of a computational environment with an explicit control about the management of resources.This paper introduces a typed functional language ! and a categorical model for it.The terms of ! encode a version of natural deduction for Intuitionistic Linear Logic such that linear and non linear assumptions are managed multiplicatively and additively, respectively. Correspondingly, the terms of ! are built out of two disjoint sets of variables. Moreover, the -abstractions of ! bind variables and patterns. The use of two different kinds of variables and the patterns allow a very compact definition of the one-step operational semantics of !, unlike all other extensions of Curry-Howard Isomorphism to Intuitionistic Linear Logic. The language ! is Church-Rosser and enjoys both Strong Normalizability and Subject Reduction.The categorical model induces operational equivalences like, for example, a set of extensional equivalences.The paper presents also an untyped version of ! and a type assignment for it, using formulas of Linear Logic as types. The type assignment inherits from ! all the good computational properties and enjoys also the Principal-Type Property.     

A small step for rats alters spatial behavior: rats on a bi-level arena explore each level separately

Animal Cognition - We tested rats on a ‘bi-level open-field’ whose two halves were separated vertically by an 8-cm step that the rats could easily ascend/descend. We sought to determine...     

Scaffolding emotions and evolving language

We suggest that, in animals, the core-affect system is linked to partially assimilated behavioral dispositions that act as developmental scaffolds for the ontogenetic construction of emotions. We also propose that in humans the evolution of language altered the control of emotions, leading to categories that can be adequately captured only by emotion-words.     

Affective states leak into movement execution: Automatic avoidance of threatening stimuli in fear of spider is visible in reach trajectories

Approach-like actions are initiated faster with stimuli of positive valence. Conversely, avoidance-like actions are initiated faster with threatening stimuli of negative valence. We went beyond reaction time measures and investigated whether threatening stimuli also affect the way in which an action is carried out. Participants moved their hand either away from the picture of a spider (avoidance) or they moved their hand toward the picture of a spider (approach). We compared spider-fearful participants to non-anxious participants. When reaching away from the threatening spider picture, spider-fearful participants moved more directly to the target than controls. When reaching toward the threatening spider, spider-fearful participants moved less directly to the target than controls. Some conditions that showed clear differences in movement trajectories between spider-fearful and control participants were devoid of differences in reaction time. The deviation away from threatening stimuli provides evidence for the claim that affective states like fear leak into movement programming and produce deviations away from threatening stimuli in movement execution. Avoidance of threatening stimuli is rapidly integrated into ongoing motor behaviour in order to increase the distance between the participant's body and the threatening stimulus.     

Approach and avoidance movements are unaffected by cognitive conflict: A comparison of the Simon effect and stimulus–response compatibility

Participants in this study reached from central fixation to a lateral position that either contained or was opposite to the stimulus. Cognitive conflict was induced when the stimulus and response directions did not correspond. In the Simon task, the response direction was cued by the color of the lateral stimulus, and corresponding and noncorresponding trials varied randomly in the same block of trials, resulting in high uncertainty and long reaction times (RTs). In the stimulus-response compatibility (SRC) task, participants reached toward or away from the stimulus in separate blocks of trials, resulting in low uncertainty and short RTs. In the SRC task, cognitive conflict in noncorresponding trials slowed down RTs but hardly affected reach trajectories. In the Simon task, both RTs and reach trajectories were strongly influenced by stimulus-response correspondence. Despite the overall longer RTs in the Simon task, reaches were less direct and deviated toward the stimulus in noncorresponding trials. Thus, cognitive conflict was resolved before movement initiation in the SRC task, whereas it leaked into movement execution in the Simon task. Current theories of the Simon effect, such as the gating of response activation or response code decay, are inconsistent with our results. We propose that the SRC task was decomposed as approaching and avoiding the stimulus, which is sustained by stereotyped visuomotor routines. With complex stimulus-response relationships (Simon task), responses had to be coded as leftward and rightward, with more uncertainty about how to execute the action. This uncertainty permitted cognitive conflict to leak into the movement execution.     

Confirming expectations in asymmetric and symmetric social hypothesis testing

This article examines individuals' expectations in a social hypothesis testing task. Participants selected questions from a list to investigate the presence of personality traits in a target individual. They also identified the responses that they expected to receive and the likelihood of the expected responses. The results of two studies indicated that when people asked questions inquiring about the hypothesized traits that did not entail strong a priori beliefs, they expected to find evidence confirming the hypothesis under investigation. These confirming expectations were more pronounced for symmetric questions, in which the diagnosticity and frequency of the expected evidence did not conflict. When the search for information was asymmetric, confirming expectations were diminished, likely as a consequence of either the rareness or low diagnosticity of the hypothesis-confirming outcome. We also discuss the implications of these findings for confirmation bias.     

Assessing Vindictiveness: Psychological Aspects by a Reliability and Validity Study of the Vengeance Scale in the Italian Context

Vengeance can be commonly defined as the disposition towards the infliction of harm in return for perceived injury or insult or as simply getting back at another person. This paper describes a contribution to the Italian validation of the Vengeance Scale (Stuckless and Goranson, Journal of social Behavior and Personality 7: 25?C42, 1992) following the same steps of the original authors and shows psychological implications of vindictive behavior. 377 under-graduate students responded to the Big Five Questionnaire, State Trait Anger Expression Inventory and a back-translated Italian version of the Vengeance Scale (IVS). The IVS shows good psychometric properties. Convergent validity is shown by correlations with crucially connected variables (anger, empathy, social desirability). Factorial analysis suggested that the IVS is basically a one-dimensional measure. Regression analysis reveals that empathy, anger and emotional stability are significant predictors of vengeance. General results show that the IVS is a good instrument of evaluation of the tendency to be vindictive. Statistic analysis highlights that specific personality traits are involved in vindictive behavior; furthermore the interactions between some features of subject and the environment appear determinant. The implications and utility of the IVS in future research are discussed.     

Asymmetric Perception of Gains versus Non‐losses and Losses versus Non‐gains: The Causal Role of Regulatory Focus

Recent studies show that, while losses loom larger than equivalent non‐gains, gains loom larger than equivalent non‐losses. This finding has been interpreted within the framework of regulatory focus theory. In this study, we highlight the importance of considering the motivational focus independently of the framing and the valence of outcome, thus exploring the causal effect of regulatory focus on the asymmetric perception of gains versus non‐losses and losses versus non‐gains. In two studies, we examine the perceived effects of either actual or hypothetical changes in monetary wealth, while orthogonally manipulating framing, valence, and regulatory focus. We find a significant interaction between the three factors. The gain versus non‐loss asymmetry in perceived satisfaction is stronger in promotion focus, whereas the loss versus non‐gain asymmetry in perceived dissatisfaction is stronger in prevention focus. The results suggest that the effects of incentives framed in terms of (non)gains and (non)losses depend on their congruence with the individual's motivational state. Copyright © 2013 John Wiley & Sons, Ltd.