3 research outputs found
Influence of the Geometry of the world model on Curiosity Based Exploration
In human spatial awareness, 3-D projective geometry structures information
integration and action planning through perspective taking within an internal
representation space. The way different perspectives are related and transform
a world model defines a specific perception and imagination scheme. In
mathematics, such collection of transformations corresponds to a 'group', whose
'actions' characterize the geometry of a space. Imbuing world models with a
group structure may capture different agents' spatial awareness and affordance
schemes. We used group action as a special class of policies for
perspective-dependent control. We explored how such geometric structure impacts
agents' behavior, comparing how the Euclidean versus projective groups act on
epistemic value in active inference, drive curiosity, and exploration
behaviors. We formally demonstrate and simulate how the groups induce distinct
behaviors in a simple search task. The projective group's nonlinear
magnification of information transformed epistemic value according to the
choice of frame, generating behaviors of approach toward an object of interest.
The projective group structure within the agent's world model contains the
Projective Consciousness Model, which is know to capture key features of
consciousness. On the other hand, the Euclidean group had no effect on
epistemic value : no action was better than the initial idle state. In
structuring a priori an agent's internal representation, we show how geometry
can play a key role in information integration and action planning
The effectiveness of natalizumab vs fingolimod–A comparison of international registry studies
International audienceBackground: Natalizumab and fingolimod were the first preparations recommended for disease breakthrough in priorly treated relapsing-remitting multiple sclerosis. Of three published head-to-head studies two showed that natalizumab is the more effective to prevent relapses and EDSS worsening.Methods: By re-analyzing original published results from MSBase, France, and Denmark using uniform methodologies, we aimed at identifying the effects of differences in methodology, in the MS-populations, and at re-evaluating the differences in effectiveness between the two drugs. We gained access to copies of the individual amended databases and pooled all data. We used uniform inclusion/exclusion criteria and statistical methods with Inverse Probability Treatment Weighting.Results: The pooled analyses comprised 968 natalizumab- and 1479 fingolimod treated patients. The on-treatment natalizumab/fingolimod relapse rate ratio was 0.77 (p=0.004). The hazard ratio (HR) for a first relapse was 0.82 (p=0.030), and the HR for sustained EDSS improvement was 1.4 (p=0.009). There were modest differences between each of the original published studies and the replication study, but the conclusions of the three original studies remained unchanged: in two of them natalizumab was more effective, but in the third there was no difference between natalizumab and fingolimod.Conclusion: The results were largely invariant to the epidemiological and statistical methods but differed between the MS populations. Generally, the advantage of natalizumab was confirmed