Cognitive Fatigue, Sleep and Cortical Activity in Multiple Sclerosis Disease. A Behavioral, Polysomnographic and Functional Near-Infrared Spectroscopy Investigation

Patients with multiple sclerosis (MS) disease frequently experience fatigue as their most debilitating symptom. Fatigue in MS partially refers to a cognitive component, cognitive fatigue (CF), characterized by a faster and stronger than usual development of the subjective feeling of exhaustion that follows sustained cognitive demands. The feeling of CF might result from supplementary task-related brain activity following MS-related demyelination and neurodegeneration. Besides, CF in MS disease might also stem from disrupted sleep. The present study investigated the association between the triggering of CF, task-related brain activity and sleep features. In a counterbalance mixed design, 10 patients with MS and 11 healthy controls were exposed twice for 16 min to a CF-inducing dual working memory updating task (TloadDback) under low or high cognitive demands conditions, counterbalanced. Considering known inter-individual differences and potential cognitive deficits in MS, the maximal cognitive load of the task was individually adapted to each participant’s own upper limits. During the experimental sessions, cortical brain activity was measured using near-infrared spectroscopy (NIRS) during the CF-induction task, and in a resting state immediately before and after. Ambulatory polysomnography recordings were obtained on the nights preceding experimental sessions. When cognitive load was individually adapted to their processing capabilities, patients with MS exhibited similar than healthy controls levels of subjectively perceived CF, evolution of performance during the task, and brain activity patterns. Linear mixed models indicate a negative association between oxygenation level changes in the dorsolateral prefrontal cortex (DLPFC) and the triggering of subjective CF in patients with MS only. Longer total sleep time was also associated with higher CF in MS patients. These results suggest that controlling for cognitive load between individuals with and without MS results in a similar task-related development of subjective CF. Besides comparable performance and cortical brain activity between groups, mixed model analyses suggest a possible association between CF, DLPFC activity and sleep duration in MS disease

Riociguat treatment in patients with chronic thromboembolic pulmonary hypertension: Final safety data from the EXPERT registry

Objective: The soluble guanylate cyclase stimulator riociguat is approved for the treatment of adult patients with pulmonary arterial hypertension (PAH) and inoperable or persistent/recurrent chronic thromboembolic pulmonary hypertension (CTEPH) following Phase

Fluctuations of Reaction Time Modulate Automatic Inhibition of Masked Primes

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The Temporal Dynamic of Automatic Inhibition of Irrelevant Actions

Motor inhibition can occur even without conscious perception and any voluntary effort. Although it is now clear that such an inhibitory process needs time to unfold, its exact temporal dynamic remains to be elucidated. Therefore, the present study aims to examine the impact of various temporal factors on automatic motor inhibition using the masked priming task. Results shows that this process can be modulated by any factor that introduces time between the mask onset and the execution of target response, whether it stems from a purely external origin (mask-target SOA), a purely internal origin (spontaneous reaction time [RT] fluctuations), or a mix of both (RT fluctuations from the target sequence). Moreover, when the external temporal factor could not determine the direction of prime influence, the RT fluctuations had the strongest impact on the priming effect. These RT fluctuations are plausibly because of spontaneous trial-to-trial changes from more impulsive and error-prone decisions to more cautious and accurate decisions to the target. Indeed, both accuracy and speed were equally required during the task, but both requirements are impossible to achieve perfectly in every trial. This suggests that fluctuations in the level of caution in voluntary decisions can modulate unconscious and involuntary motor inhibition.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

The repeated masked paradigm or how to increase the awareness of a non-conscious stimulus.

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Visual masking revisited: number of repetitions and voluntary attention modulate priming and conscious access of a masked stimulus.

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Repeating a strongly masked stimulus increases priming and awareness.

Previous studies [Marcel, A. J. (1983). Conscious and unconscious perception: Experiments on visual masking and word recognition. Cognitive Psychology, 15(2), 197-237; Wentura, D. & Frings, C. (2005). Repeated masked category primes interfere with related exemplars: New evidence for negative semantic priming. Journal of Experimental Psychology: Learning, Memory, and Cognition, 31(1), 108-120] suggested that repeatedly presenting a masked stimulus improves priming without increasing perceptual awareness. However, neural theories of consciousness predict the opposite: Increasing bottom-up strength in such a paradigm should also result in increasing availability to awareness. Here, we tested this prediction by manipulating the number of repetitions of a strongly masked digit. Our results do not replicate the dissociation observed in previous studies and are instead suggestive that repeating an unconscious and attended masked stimulus enables the progressive emergence of perceptual awareness.Journal ArticleSCOPUS: ar.jinfo:eu-repo/semantics/publishe

The impact of masking method on both priming effect and consciousness

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The reversal of perceptual and motor congruency effects differs qualitatively between metacontrast and random-line masks

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