256 research outputs found
Characterising Probabilistic Processes Logically
In this paper we work on (bi)simulation semantics of processes that exhibit
both nondeterministic and probabilistic behaviour. We propose a probabilistic
extension of the modal mu-calculus and show how to derive characteristic
formulae for various simulation-like preorders over finite-state processes
without divergence. In addition, we show that even without the fixpoint
operators this probabilistic mu-calculus can be used to characterise these
behavioural relations in the sense that two states are equivalent if and only
if they satisfy the same set of formulae.Comment: 18 page
Testing Reactive Probabilistic Processes
We define a testing equivalence in the spirit of De Nicola and Hennessy for
reactive probabilistic processes, i.e. for processes where the internal
nondeterminism is due to random behaviour. We characterize the testing
equivalence in terms of ready-traces. From the characterization it follows that
the equivalence is insensitive to the exact moment in time in which an internal
probabilistic choice occurs, which is inherent from the original testing
equivalence of De Nicola and Hennessy. We also show decidability of the testing
equivalence for finite systems for which the complete model may not be known
Metacognitive scaffolding boosts cognitive and neural benefits following executive attention training in children
Version of Record online: 25 October 2018Interventions including social scaffolding and metacognitive strategies have been used in
educational settings to promote cognition. In addition, increasing evidence shows that
computerized process-based
training enhances cognitive skills. However, no prior studies
have examined the effect of combining these two training strategies. The goal of this
study was to test the combined effect of metacognitive scaffolding and computer-based
training of executive attention in a sample of typically developing preschoolers at the
cognitive and brain levels. Compared to children in the regular training protocol and an
untrained active control group, children in the metacognitive group showed larger gains
on intelligence and significant increases on an electrophysiological index associated with
conflict processing. Moreover, changes in the conflict-related
brain activity predicted
gains in intelligence in the metacognitive scaffolding group. These results suggest that
metacognitive scaffolding boosts the influence of process-based
training on cognitive
efficiency and brain plasticity related to executive attention.Secretaría de Estado de Investigación,
Desarrollo e Innovación, Grant/Award
Number: PSI2014-55833-
Emergence of qualia from brain activity or from an interaction of proto-consciousness with the brain: which one is the weirder? Available evidence and a research agenda
This contribution to the science of consciousness aims at comparing how two different theories can
explain the emergence of different qualia experiences, meta-awareness, meta-cognition, the placebo
effect, out-of-body experiences, cognitive therapy and meditation-induced brain changes, etc.
The first theory postulates that qualia experiences derive from specific neural patterns, the second
one, that qualia experiences derive from the interaction of a proto-consciousness with the brain\u2019s
neural activity. From this comparison it will be possible to judge which one seems to better explain
the different qualia experiences and to offer a more promising research agenda
Neural Correlates of Ongoing Conscious Experience: Both Task-Unrelatedness and Stimulus-Independence Are Related to Default Network Activity
The default mode network (DMN) is a set of brain regions that consistently shows higher activity at rest compared to tasks requiring sustained focused attention toward externally presented stimuli. The cognitive processes that the DMN possibly underlies remain a matter of debate. It has alternately been proposed that DMN activity reflects unfocused attention toward external stimuli or the occurrence of internally generated thoughts. The present study aimed at clarifying this issue by investigating the neural correlates of the various kinds of conscious experiences that can occur during task performance. Four classes of conscious experiences (i.e., being fully focused on the task, distractions by irrelevant sensations/perceptions, interfering thoughts related to the appraisal of the task, and mind-wandering) that varied along two dimensions (“task-relatedness” and “stimulus-dependency”) were sampled using thought-probes while the participants performed a go/no-go task. Analyses performed on the intervals preceding each probe according to the reported subjective experience revealed that both dimensions are relevant to explain activity in several regions of the DMN, namely the medial prefrontal cortex, posterior cingulate cortex/precuneus, and posterior inferior parietal lobe. Notably, an additive effect of the two dimensions was demonstrated for midline DMN regions. On the other hand, lateral temporal regions (also part of the DMN) were specifically related to stimulus-independent reports. These results suggest that midline DMN regions underlie cognitive processes that are active during both internal thoughts and external unfocused attention. They also strengthen the view that the DMN can be fractionated into different subcomponents and reveal the necessity to consider both the stimulus-dependent and the task-related dimensions of conscious experiences when studying the possible functional roles of the DMN
Biases in the Explore-Exploit Tradeoff in Addictions: The Role of Avoidance of Uncertainty.
We focus on exploratory decisions across disorders of compulsivity, a potential dimensional construct for the classification of mental disorders. Behaviors associated with the pathological use of alcohol or food, in alcohol use disorders (AUD) or binge-eating disorder (BED), suggest a disturbance in explore-exploit decision-making, whereby strategic exploratory decisions in an attempt to improve long-term outcomes may diminish in favor of more repetitive or exploitatory choices. We compare exploration vs exploitation across disorders of natural (obesity with and without BED) and drug rewards (AUD). We separately acquired resting state functional MRI data using a novel multi-echo planar imaging sequence and independent components analysis from healthy individuals to assess the neural correlates underlying exploration. Participants with AUD showed reduced exploratory behavior across gain and loss environments, leading to lower-yielding exploitatory choices. Obese subjects with and without BED did not differ from healthy volunteers but when compared with each other or to AUD subjects, BED had enhanced exploratory behaviors particularly in the loss domain. All subject groups had decreased exploration or greater uncertainty avoidance to losses compared with rewards. More exploratory decisions in the context of reward were associated with frontal polar and ventral striatal connectivity. For losses, exploration was associated with frontal polar and precuneus connectivity. We further implicate the relevance and dimensionality of constructs of compulsivity across disorders of both natural and drug rewards.The study was funded by the Wellcome Trust Fellowship grant for VV (093705/Z/10/Z) and Cambridge NIHR Biomedical Research Centre. VV and NAH are Wellcome Trust (WT) intermediate Clinical Fellows. LSM is in receipt of an MRC studentship. The BCNI is supported by a WT and MRC grant. MF is funded by NIMH and NSF grants and is consultant for Hoffman LaRoche pharmaceuticals. The remaining authors declare no competing financial interests.This is the final version of the article. It first appeared from NPG via http://dx.doi.org/10.1038/npp.2015.20
Effectiveness of initiating biologics in severe asthma patients with high steroid exposure
Peer reviewedPostprin
British press attitudes towards the EU's global presence:from the Russian-Georgian War to the 2009 Copenhagen Summit
This article surveys the way in which British print media have presented the European Union (EU)'s global presence in the international arena by analysing two case studies which reflect two very distinctive areas of EU foreign policy: global climate change policy and the policy towards Russia. It employs frame analysis, allowing for the identification of the way in which the discourse of the press was categorized around a series of central opinions and ideas. Frames underscore the connections made by journalists between different events, policies or phenomena and their possible interpretations. The analysis highlights that acting through the common framework of the EU rather than unilaterally was a strategy preferred by the British press. These findings are in stark contrast with the deep Euroscepticism which characterizes press attitudes towards most policy areas, and is often considered to be rooted in the British political culture, media system, public opinion or the longstanding tradition of viewing the European continent as the other
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