This study examined the hypothesis that conditional reasoning involves visual short-term memory resources (Johnson-Laird, 1985). A total of 147 university students were given measures of verbal and visual short-term memory capacity and a series of concrete and abstract conditional reasoning problems. Results indicate that there is a positive correlation between verbal working memory capacity and reasoning with both concrete and abstract premises. A positive correlation was also obtained between visual working memory capacity and reasoning with concrete premises.
BackgroundResearch ethics and the measures deployed to ensure ethical oversight of research are vested with extremely important ethical and practical goals. Accordingly, these measures need to function effectively in real-world research and to follow high level standards.MethodsWe examined approved consent forms for Magnetic Resonance Imaging and functional Magnetic Resonance Imaging studies approved by Canadian research ethics boards .ResultsWe found evidence of variability in consent forms in matters of physical and psychological risk reporting. Approaches used to tackle the emerging issue of (...) incidental findings exposed extensive variability between and within research sites.ConclusionThe causes of variability in approved consent forms and studies need to be better understood. However, mounting evidence of administrative and practical hurdles within current ethics governance systems combined with potential sub-optimal provision of information to and protection of research subjects support other calls for more scrutiny of research ethics practices and applicable revisions. (shrink)
Chaos theory is a rapidly growing field. As a technical term, chaos refers to deterministic but unpredictable processes being sensitively dependent upon initial conditions. Neurobiological models and experimental results are very complicated and some research groups have tried to pursue the neuronal chaos. Babloyantz's group has studied the fractal dimension (d) of electroencephalograms (EEG) in various physiological and pathological states. From deep sleep (d=4) to full awakening (d>8), a hierarchy of strange attractors paralles the hierarchy of states of consciousness. In (...) epilepsy (petit mal), despite the turbulent aspect of a seizure, the attractor dimension was near to 2. In Creutzfeld-Jacob disease, the regular EEG activity corresponded to an attractor dimension less than the one measured in deep sleep. Is it healthy to be chaotic? An active desynchronisation could be favourable to a physiological system. Rapp's group reported variations of fractal dimension according to particular tasks. During a mental arithmetic task, this dimension increased. In another task, a P300 fractal index decreased when a target was identified. It is clear that the EEG is not representing noise. Its underlying dynamics depends on only a few degrees of freedom despite yet it is difficult to compute accurately the relevant parameters.What is the cognitive role of such a chaotic dynamics? Freeman has studied the olfactory bulb in rabbits and rats for 15 years. Multi-electrode recordings of a few mm2 showed a chaotic hierarchy from deep anaesthesia to alert state. When an animal identified a previously learned odour, the fractal dimension of the dynamics dropped off (near limit cycles). The chaotic activity corresponding to an alert-and-waiting state seems to be a field of all possibilities and a focused activity corresponds to a reduction of the attractor in state space. For a couple of years, Freeman has developed a model of the olfactory bulb-cortex system. The behaviour of the simple model without learning was quite similar to the real behaviour and a model with learning is developed. (shrink)
In his collection of essays Having the World in View (2009), John McDowell draws a distinction between empirical experience (conceived as the conceptual activity relevant to judgment) and empirical judgment (i.e., the full-fledged assertoric content itself ). McDowell’s latest proposal is that the form of empirical experience is transferable into judgment, but it is not itself a judgment. Taking back the view he advanced in Mind and World, McDowell now believes that perception does not have propositional content as such, but (...) the content of perception can, however, always be actualized in a judgment. There is, in other words, a strict parallelism between the deliverances of sensibility and potential future judgments of experience. The early Husserl disagrees with this and recognizesexplicitly the existence of coherent forms of perceptual engagement with the world that is independent of the mastery of language and the use of concepts.Perception constitutes—together with certain other embodied practices—our primary mode of access to the world, and this occurs before and independently ofour thinking activity. However, the realization of the centrality of time for intentionality will lead Husserl after 1905 to recognize a kind of lawfulness internal tothe sensuous materials themselves, prior to any egoical achievement. The most immediate consequence of this paradigm change is that the very idea of non-conceptual content now seems unwarranted. Indeed, if time is that which keeps the process of sense formation unified even at the lowest levels of constitution, then the world-disclosing activity of the ego cannot be discontinuous with the conceptual realm. Against this background, it will be argued that the dialectic between the conceptual and non-conceptual ultimately makes no sense on a phenomenological basis. Once temporality has entered the scene, the only meaningful opposition that stands is that between the conceptual and pre-conceptual spheres. (shrink)
The paper is organized around two ideas that come out in Steve Crowell’s Normativity and Phenomenology in Husserl and Heidegger and that I discuss critically in turn. The first concerns the reach of Crowell’s claim according to which the connection between intentionality, meaning and normativity is necessary in all forms of intentional experience. I make my point by considering the case of imagining experiences, which are—I argue—meaningful, intentional, but not necessarily normative in any relevant sense. The second question is about (...) Crowell’s criticism of the role of bodily self-awareness in Husserl’s phenomenology of perception. While Crowell is right to maintain that the norm of proper functioning relevant to bodily skills can’t be understood as arising from a system of kinaesthetic sensations alone, I argue that bodily self-awareness still has a normative role to play in perception inasmuch as it allows me to cast my own experience in evaluative terms. (shrink)
Chaos in nervous system is a fascinating but controversial field of investigation. To approach the role of chaos in the real brain, we theoretically and numerically investigate the occurrence of chaos inartificial neural networks. Most of the time, recurrent networks (with feedbacks) are fully connected. This architecture being not biologically plausible, the occurrence of chaos is studied here for a randomly diluted architecture. By normalizing the variance of synaptic weights, we produce a bifurcation parameter, dependent on this variance and on (...) the slope of the transfer function, that allows a sustained activity and the occurrence of chaos when reaching a critical value. Even for weak connectivity and small size, we find numerical results in accordance with the theoretical ones previously established for fully connected infinite sized networks. The route towards chaos is numerically checked to be a quasi-periodic one, whatever the type of the first bifurcation is. Our results suggest that such high-dimensional networks behave like low-dimensional dynamical systems. (shrink)
Following Karni's seminal work, Walker and other researchers have recently provided gradually convincing evidence that sleep is critical for the consolidation-based enhancement (CBE) of motor sequence learning. Studies in our laboratory using a motor adaptation paradigm, however, show that CBE can also occur after the simple passage of time, suggesting that sleep effects on memory consolidation are task-related, and possibly dependent on anatomically dissociable circuits.
The dynamical behaviour of a very general model of neural networks with random asymmetric synaptic weights is investigated in the presence of random thresholds. Using mean-field equations, the bifurcations of the fixed points and the change of regime when varying control parameters are established. Different areas with various regimes are defined in the parameter space. Chaos arises generically by a quasi-periodicity route.
Childhood innocence has often been treated by scholars as an empty, idealised signifier. This article contests such accounts, arguing that innocence is best regarded as a powerfully unmarked training in heternormativity, alongside class and race norms. This claim will be demonstrated through attention to two recent films addressing childhood: Celine Sciamma’s Tomboy and P.J. Hogan’s Peter Pan. The films characterise young femininity as an ‘impossible space’, in which subjects face the contradictory, schizoid demands to simultaneously show both childhood innocence (...) and heteronormative femininity – or else face the threat of a spoiled identity. The plot of each film traces how the protagonist attempts to manoeuvre in the face of and precisely using this contradiction. In dramatising such manoeuvring, the films reveal the surprising forms of subjectivity that can be inhabited for a time in the interstices between age and gender norms, and which might have lasting value. Both films thus drama... (shrink)