Defending psychopathy: an argument from values and moral responsibility

How psychopaths and their capacity for moral action are viewed is not only philosophically interesting but is also important and relevant for policy. The philosophical discussion of psychopathy has focussed upon the psychological faculties that are prerequisites for moral responsibility and empirical findings regarding psychopathy that are relevant to philosophical accounts of moral understanding and motivation. However, there are legitimate worries about whether psychopathy is a robust scientific construct, and there are risks attached to reifying psychopathy or other psychiatric constructs. We defend the concept of psychopathy by pointing out the relevance of empirical studies about it for our ordinary practices of ascribing moral responsibility and folk psychological accounts of moral understanding and motivation.     

An Analysis of Item Response Theory and Rasch Models Based on the Most Probable Distribution Method

The most probable distribution method is applied to derive the logistic model as the distribution accounting for the maximum number of possible outcomes in a dichotomous test while introducing latent traits and item characteristics as constraints to the system. The item response theory logistic models, with a particular focus on the one-parameter logistic model, or Rasch model, and their properties and assumptions, are discussed for both infinite and finite populations.     

The Naturality of Natural Deduction (II): On Atomic Polymorphism and Generalized Propositional Connectives

Studia Logica - In a previous paper (of which this is a prosecution) we investigated the extraction of proof-theoretic properties of natural deduction derivations from their impredicative...     

Decoding Gentzen's Notation

In this note we consider Gentzen's first ordinal notation, used in his first published proof of the consistency of Peano Arithmetic (1936). It is a decimal notation, quite different from our current notations. We give a rule to translate this notation into our usual set-theoretic notation and we show some of its peculiarities. Then we indicate how to decode Gentzen's assignment of ordinal notations to derivations and give some examples. Finally, we go through his proof of their decrease after the application of his reduction procedure, giving further examples.     

Differentiated forgetting rates of spatial knowledge in humans in the absence of repeated testing

Spatial knowledge, necessary for efficient navigation, comprises route knowledge (memory of the landmarks along a route) and survey knowledge (map-like). Available data on the retention in humans of spatial knowledge show that this does not decline systematically over months or years. Here, two groups of participants elaborated route and survey knowledge during navigation in a complex virtual environment before performing route and survey tasks. Both groups were tested 5 minutes after learning and 3 months later, while one group was also tested 1 week and 1 month later (repeated testing). Performance was similar in both groups on the first testing session, remained stable in the repeated tested group, but decreased in the non-repeated tested group, especially on route tasks. These results are the first to reveal a substantial and selective decline of spatial knowledge, occurring only if there is no possibility of reactivating knowledge along repeated testing.     

The handedness of imagined bodies in action and the role of perspective taking

Past research at the nexus of motor control and perception investigated the role of perspective taking in many behavioral and neuroimaging studies. Some investigators addressed the issue of one's own vs. others' action imagination, but the possible effects of a front or a back view in imagining others' actions have so far been neglected. We report two 'single trial' experiments in which a total of 640 participants were asked to imagine a person performing a manual action - either in a front or in a back view - and then to indicate the hand used by the imagined person during movement execution. In such a task, we assume the existence of two distinct biases: a perceptual-mnemonic bias due to subjects' visual experience of others' actions, encouraging them to imagine right-handed movements, and a motor bias due to subjects' experience of self-made actions, encouraging them to imagine movements performed with the same hand as their dominant hand. We hypothesized that a greater involvement of motor representations in the back view compared to the front view could result in an increased correspondence between one's own manual preference and the hand used by the imagined agent in the former condition. The results of both experiments were consistent with this hypothesis, suggesting that while imagining others' actions we employ motor simulations in different degrees according to the perspective adopted.     

"Binaural rivalry": dichotic listening as a tool for the investigation of the neural correlate of consciousness

Since about two decades neuroscientists have systematically faced the problem of consciousness: the aim is to discover the neural activity specifically related to conscious perceptions, i.e. the biological properties of what philosophers call qualia. In this view, a neural correlate of consciousness (NCC) is a precise pattern of brain activity that specifically accompanies a particular conscious experience. Almost all studies aimed at investigating the NCC have been carried out in the visual system. One of the most promising paradigms is based on sensory stimuli which elicit bistable percepts, as they allow to decouple subjective perception from the characteristics of the physical stimulation. Such kind of perception can be produced in the visual modality by using particular images (e.g. Rubin's vase/face figure) or by presenting two dissimilar stimuli separately to the two eyes (binocular rivalry). The stimuli compete for perceptual dominance and each image is visible in turn for a few seconds, while the other is suppressed. The use of this methodology has led to important findings concerning visual consciousness, which are briefly discussed. For the investigation of auditory consciousness, a similar stimulation paradigm can be achieved by using dichotic listening, consisting in two different stimuli presented each to one ear, which compete for perception (binaural rivalry). The principal aim of the present mini-review is to discuss the few contributes facing the issue of auditory consciousness and to advance the use of dichotic listening and binaural rivalry as valid tools for its investigation.     

The contact principle and utilitarian moral judgments in young children

In three experiments involving 207 preschoolers and 28 adults, we investigated the extent to which young children base moral judgments of actions aimed to protect others on utilitarian principles. When asked to judge the rightness of intervening to hurt one person in order to save five others, the large majority of children aged 3 to 5 years advocated intervention in contrast to another situation with the reverse cost/benefit ratio. This course of action was seen as acceptable by most children only when it did not require the agent to have physical contact with the victim and the victim’s harm was intended to produce the greatest good for the greatest number. Overall, the children’s responses were remarkably similar to those reported in adult studies. These findings document the extent to which some constraints on moral judgment are present in early human development.