Elaborating the police perspective: The role of perceptions and experience in the explanation of crowd conflict

Classical theories of crowd behaviour view crowd conflict as deriving from the pathology of the crowd itself. Recent developments in crowd psychology as the elaborated social identity model (ESIM) conceptualize crowd behaviour as a dynamic intergroup process between demonstrators and police. The present study assessed exposure to crowd conflict, adherence to classical views of crowd behaviour, public order policing methods and attributions of responsibility for crowd conflict among 352 Italian police officers. Results showed that exposure to crowd conflict was related to adherence to classical views of crowd, which, in turn, was related to ‘bad practices’ of public order policing and to system‐justificatory attributions. Overall, these results offer support and extend the police perspective within the ESIM model. Practical implications for public order policing strategies and training are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.     

Mirror neurons in humans: consisting or confounding evidence?

The widely known discovery of mirror neurons in macaques shows that premotor and parietal cortical areas are not only involved in executing one's own movement, but are also active when observing the action of others. The goal of this essay is to critically evaluate the substance of functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) studies whose aim has been to reveal the presence of a parallel system in humans. An inspection of this literature suggests that there is relatively weak evidence for the existence of a circuit with 'mirror' properties in humans, such as that described in monkeys.     

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.     

Concreteness effects in free recall: The roles of imaginai and relational processing

Two experiments reevaluated the possible role of mental imagery in free recall of concrete and abstract words. In Experiment 1, the number and rate of list presentations were manipulated. Incidental recall following an imagery rating task yielded reliable concreteness effects after two presentations but not after a single presentation, regardless of presentation rate. In Experiment 2, we examined the effects of relational (categorization) and item-specific (imagery rating) processing tasks on memory for categorically related or unrelated concrete and abstract words. Concreteness effects were obtained when unrelated words were sorted into categories but not when they were rated on imagery. Related words failed to yield concreteness effects under any orienting condition. The results support the view that the presence or absence of concreteness effects in free recall depends on the relative salience of distinctive and relational information. This conclusion constrains theoretical explanations of the role of mental imagery in memory and cognition.     

Finger-digit compatibility in Arabic numeral processing

Finger-digit response compatibility was tested by asking participants to identify Arabic digits by pressing 1 of 10 keys with all 10 fingers. The direction of the finger-digit mapping was varied by manipulating the global direction of the hand-digit mapping as well as the direction of the finger-digit mapping within each hand (in each case, from small to large digits, or the reverse). The hypothesis of a left-to-right mental number line predicted that a complete left-to-right mapping should be easier whereas the hypothesis of a representation based on finger counting predicted that a counting-congruent mapping should be easier. The results show that when all 10 fingers are used to answer, a mapping congruent with the prototypical finger-counting strategy reported by the participants leads to better performance than does a mapping congruent with a left-to-right oriented mental number line, both in palm-down and palm-up postures of the hands, and they demonstrate that finger-counting strategies influence the way that numerical information is mentally represented and processed.     

What face inversion does to infants' counting abilities

Infants younger than 1 year do not correctly count the number of objects in a scene by using differences among their properties, unless these differences cross the broad category boundaries separating humans, animals, and artifacts. Here we show that face orientation influences whether 10- and 12-month-old infants count correctly or incorrectly. When infants saw two puppets appearing and disappearing behind an occluder successively and had no cues for numerosity other than differences among the puppets' properties, they correctly counted two puppets if one had an upright face and one an upside-down face. However, when the same puppets were both shown with faces upright, infants failed the task. Overall, this pattern of success and failure closely parallels the pattern of brain activations registered when adults and infants watch objects characterized by the same property contrasts.     

Why should we abandon the mental logic hypothesis?

Two hypotheses on deductive reasoning are under development: mental logic and mental models. It is often accepted that there are overwhelming arguments to reject the mental logic hypothesis. I revise these arguments and claim that they are either not conclusive, or point at problems which are troublesome for the mental model hypothesis as well.     

Numerical representations and intuitions of probabilities at 12 months

Recent research shows that preverbal infants can reason about single‐case probabilities without relying on observed frequencies, adapting their predictions to relevant dynamic parameters of the situation (Téglás, Vul, Girotto, Gonzalez, Tenenbaum & Bonatti, 2011 ; Téglás, Girotto, Gonzalez & Bonatti, 2007 ). Here we show that intuitions of probabilities may derive from the ability to represent a limited number of possibilities. After watching a scene containing moving objects of two ensembles, 12‐month‐olds looked longer at an unlikely than at a likely single‐case outcome when the objects were within the parallel individuation range. However, they did not do so when the scene contained the same ratio between ensembles but a larger number of objects. At the same time, they could form rational expectations about single‐case outcomes in scenes containing the same large number of objects when they could exploit subtle physical parameters induced by the objects’ movements and their spatial configuration. Our findings demonstrate that at early stages of development the mental representations involved in probability estimations of future individual situations are powerful and sophisticated, but at the same time they depend on infants’ overall cognitive architecture, being constrained by the numerical representations spontaneously induced by the situations.