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.     

TRoPICALS: a computational embodied neuroscience model of compatibility effects

Perceiving objects activates the representation of their affordances. For example, experiments on compatibility effects showed that categorizing objects by producing certain handgrips (power or precision) is faster if the requested responses are compatible with the affordance elicited by the size of objects (e.g., small or large). The article presents a neural-network architecture that provides a general framework to account for compatibility effects. The model was designed with a methodological approach (computational embodied neuroscience) that aims to provide increasingly general accounts of brain and behavior (4 sources of constraints are used: neuroscientific data, behavioral data, embodied systems, reproduction of learning processes). The model is based on 4 principles of brain organization that we claim underlie most compatibility effects. First, visual perception and action are organized in the brain along a dorsal neural pathway encoding affordances and a ventral pathway encoding goals. Second, the prefrontal cortex within the ventral pathway gives a top-down bias to action selection by integrating information on stimuli, context, and goals. Third, reaction times depend on dynamic neural competitions for action selection that integrate bottom-up and top-down information. The congruence or incongruence between affordances and goals explains the different reaction times found in the experiments. Fourth, as words trigger internal simulations of their referents, they can cause compatibility effects as objects do. We validated the model by reproducing and explaining 3 types of compatibility effects and showed its heuristic power by producing 2 testable predictions. We also assessed the explicative power of the model by comparing it with related models and showed how it can be extended to account for other compatibility effects.     

Ranking judgments in Arrow’s setting

In this paper, I investigate the relationship between preference and judgment aggregation, using the notion of ranking judgment introduced in List and Pettit (Synthese 140(1–2):207–235, 2004). Ranking judgments were introduced in order to state the logical connections between the impossibility theorem of aggregating sets of judgments proved in List and Pettit (Economics and Philosophy 18:89–110, 2002) and Arrow’s theorem (Arrow, Social choice and individual values, 1963). I present a proof of the theorem concerning ranking judgments as a corollary of Arrow’s theorem, extending the translation between preferences and judgments defined in List and Pettit (Synthese 140(1–2):207–235, 2004) to the conditions on the aggregation procedure.     

Formality of logic and Frege’s Begriffsschrift

This paper challenges a standard interpretation according to which Frege’s conception of logic (early and late) is at odds with the contemporary one, because on the latter’s view logic is formal, while on Frege’s view it is not, given that logic’s subject matter is reality’s most general features. I argue that Frege – in Begriffsschrift – retained the idea that logic is formal; Frege sees logic as providing the ‘logical cement’ that ties up together the contentful concepts of specific sciences, not the most general truths. Finally, I discuss how Frege conceives of the application of Begriffsschrift, and of its status as a ‘lingua characteristica’.     

Clinical Equipoise and Moral Leeway: An Epistemological Stance

Clinical equipoise (CE) has been proposed as an ethical principle relating uncertainty and moral leeway in clinical research. Although CE has traditionally been indicated as a necessary condition for a morally justified introduction of a new RCT, questions related to the interpretation of this principle remain woefully open. Recent proposals to rehabilitate CE have divided the bioethical community on its ethical merits. This paper presents a new argument that brings out the epistemological difficulties we encounter in justifying CE as a principle to connect uncertainty and moral leeway in clinical ethics. The argument proposes, first, that the methodology of hypothetical retrospection (HR) is applicable to the RCT design and that it can accommodate uncertainty. As currently understood, however, HR should give up its reliance on the assumption of uncertainty transduction, because the latter assumes the principle of indifference, which does not accommodate uncertainty in the right way. The same principle is then seen to distort also the received interpretations of CE.

     

Colours in black and white: the depiction of lightness and brightness in achromatic engravings before the invention of photography

What is it like to see the world in black and white? In the pioneer days of cinema, when movies displayed grey worlds, was it true that no 'colours' were actually seen? Did every object seen in those projections appear grey in the same way? The answer is obviously no--people in those glorious days were seeing a world full of light, shadows, and objects in which colours were expressed in terms of lightness. But the marvels of grey worlds have not always been so richly displayed. Before the invention of photography, the depiction of scenes in black-and-white had to face some technical and perceptual challenges. We have studied the technical and perceptual constraints that XV-XVIII century engravers had to face in order to translate actual colours into shades of grey. An indeterminacy principle is considered, according to which artists had to prefer the representation of some object or scene features over others (for example brightness over lightness). The reasons for this lay between the kind of grey scale technically available and the kind of information used in the construction of 3-D scenes. With the invention of photography, photomechanical reproductions, and new printing solutions, artists had at their disposal a continuous grey scale that greatly reduces the constraints of the indeterminacy principle.     

An empirical comparison of rhythm in language and music

Musicologists and linguists have often suggested that the prosody of a culture's spoken language can influence the structure of its instrumental music. However, empirical data supporting this idea have been lacking. This has been partly due to the difficulty of developing and applying comparable quantitative measures to melody and rhythm in speech and music. This study uses a recently-developed measure for the study of speech rhythm to compare rhythmic patterns in English and French language and classical music. We find that English and French musical themes are significantly different in this measure of rhythm, which also differentiates the rhythm of spoken English and French. Thus, there is an empirical basis for the claim that spoken prosody leaves an imprint on the music of a culture.     

Perceived self-efficacy and everyday problem solving among young and older adults

This research tested the hypothesis that age differences in both self-efficacy perceptions and problem-solving performance would vary as a function of the ecological relevance of problems to young and older adults. The authors developed novel everyday problem-solving stimuli that were ecologically representative of problems commonly confronted by young adults (young-adult problems), older adults (older adult problems), or both (common problems). Performance on an abstract problem solving task lacking in ecological representativeness (the Tower of Hanoi problem) also was examined. Although young persons had higher self-efficacy beliefs and performance levels on the Tower of Hanoi task problem and the young-adult problems, this pattern reversed in the domain of older adult problems, where the self-efficacy beliefs and performance of older persons exceeded those of the young.     

Memory in pregnancy and post‐partum: Item specific and relational encoding processes in recall and recognition

It has been recently proposed that pregnant women would perform memory tasks by focusing more on item‐specific processes and less on relational processing, compared to post‐partum women (Mickes, Wixted, Shapiro & Scarff, 2009 ). The present cross‐sectional study tested this hypothesis by directly manipulating the type of encoding employed in the study phase. Pregnant, post‐partum and control women either rated the pleasantness of word meaning (which induced item‐specific elaboration) or named the semantic category to which they belonged (which induced relational elaboration). Memory for the encoded words was later tested in free recall (which emphasizes relational processing) and in recognition (which emphasizes item‐specific processing). In line with Mickes et al.'s ( 2009 ) conclusions, pregnant women in the item‐specific condition performed worse than post‐partum women in the relational condition in free recall, but not in recognition. However, compared to the other two groups, pregnant women also exhibited lower recognition accuracy in the item‐specific condition. Overall, these results confirm that pregnant women rely on relational encoding less than post‐partum women, but additionally suggest that the former group might use item‐specific processes less efficiently than post‐partum and control women.     

The Map and the Territory: Complexity in Biology

In business administration or in economics it is absolutely relevant not to consider indexes like profit growth rate or gross domestic product as exhaustive indexes for economic wealth. Likewise, in biology it is important not to confuse the representation of life with life itself. The most important concepts in biology are information, memory, structure, plasticity, and robustness. Information is the difference that makes the difference. Memories are information registered in an organism. Plasticity is the capacity of a living organism to change its own structure/sets of behaviors for having a competitive advantage. Robustness is the ability of a living organism to resist environmental changes without changing its own structure/sets of behavior, and fragility is when a living organism undergoes changes in its own structure without being able to resist non-adaptive changes.