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.     

Extending the Three- and Four-Headed Eagles: The Foreign Policy Orientations of American Elites During the 80s and 90s

With the breakdown of the foreign policy consensus of the Cold War years, there has been a resurgence in examining the beliefs of the public and their role in U.S. foreign policy. The most extensive of these studies has been conducted by Holsti and Rosenau who have found first three and then four competing schools of thought. Our purpose is to build off Holsti and Rosenau's analyses and extend their argument. Research based on the content analysis of foreign policy and national opinion journals from 1980 to 1989 demonstrates that there is more diversity and complexity in the range and content of beliefs held by American leaders than Holsti and Rosenau have yet been able to capture through their "three-" and "four-headed eagles." Although the three-headed eagle serves as a useful scheme for categorizing the broad foreign policy perspectives of American leaders, it de-emphasizes important differences in beliefs and ignores at least two foreign policy orientations that exist within their general categories. This is not a mere academic exercise, for it sheds light on the level of diversity and complexity of elite beliefs, which enriches an understanding of the politics of U.S. foreign policy since Vietnam. A preliminary examination of foreign policy and national opinion journals from 1990 to 1994 indicates that American elites are changing and adapting while at the same time, they are absorbing profound global changes into their prevailing belief systems, as predicted by the political psychological literature. This suggests that the diversity and complexity present in the 80s is likely to persist and grow throughout the 90s. Our research also suggests the importance of developing alternative methods to complement reliance on survey research in order to capture more fully the diversity and complexity of the foreign policy beliefs of Americans.     

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.