Publications by authors named "Pauline Perez"

Article Synopsis
  • - The study investigates how ecology and social factors influence cognitive skills in primates by examining the size of specific brain regions related to metacognition and working memory in 16 primate species.
  • - Researchers found the volume of the frontal pole (FP) and dorso-lateral prefrontal cortex (DLPFC) is significantly related to body size, daily travel distance, and population density, indicating both ecological and social constraints play a role in cognitive evolution.
  • - The results suggest that ecological factors primarily drive brain region size, while social factors more strongly affect the FP, highlighting the importance of foraging and social interactions in the cognitive development of primates.
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Identifying the neuronal markers of consciousness is key to supporting the different scientific theories of consciousness. Neuronal markers of consciousness can be defined to reflect either the brain signatures underlying specific conscious content or those supporting different states of consciousness, two aspects traditionally studied separately. In this paper, we introduce a framework to characterize markers according to their dynamics in both the "state" and "content" dimensions.

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Pupil dilation response (PDR) has been proposed as a physiological marker of conscious access to a stimulus or its attributes, such as novelty. In a previous study on healthy volunteers, we adapted the auditory "local global" paradigm and showed that violations of global regularity elicited a PDR. Notably without instructions, this global effect was present only in participants who could consciously report violations of global regularities.

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Article Synopsis
  • - Recent research indicates that interactions between brain and heart influence our perception and self-awareness, with visceral inputs potentially shaping subjective experiences.
  • - This study examines how auditory irregularities affect both the brain's direct response to sound (measured as ERPs) and responses to heartbeats (measured as HERs) in patients with disorders of consciousness.
  • - Results reveal that distinct ERPs and HERs are produced by local and global auditory effects, helping to differentiate between minimally conscious and unresponsive wakefulness patients; HERs may serve as a new, cost-effective tool for diagnosing consciousness.
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The clinical and fundamental exploration of patients suffering from disorders of consciousness (DoC) is commonly used by researchers both to test some of their key theoretical predictions and to serve as a unique source of empirical knowledge about possible dissociations between consciousness and cognitive and/or neural processes. For instance, the existence of states of vigilance free of any self-reportable subjective experience [e.g.

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Article Synopsis
  • Understanding the role of the locus coeruleus (LC) is important for studying behaviors like stress and vigilance, and cognitive processes like attention and decision making.
  • Recent advancements in viral tools have improved our ability to study brain functions in rodents, but similar tools for primate research, especially in monkeys, are necessary for effective translational applications.
  • The described pharmacogenetics approach using DREADD allows for selective and adjustable inactivation of LC neurons, enabling researchers to explore varying effects on cognitive functions and vigilance by modifying dosages of the DREADD activator, deschloroclozapine (DCZ).
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Heart rate has natural fluctuations that are typically ascribed to autonomic function. Recent evidence suggests that conscious processing can affect the timing of the heartbeat. We hypothesized that heart rate is modulated by conscious processing and therefore dependent on attentional focus.

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Introduction: Functional brain-imaging techniques have revealed that clinical examination of disorders of consciousness (DoC) can underestimate the conscious level of patients. FDG-PET metabolic index of the best preserved hemisphere (MIBH) has been reported as a promising measure of consciousness but has never been externally validated and compared with other brain-imaging diagnostic procedures such as quantitative EEG.

Methods: FDG-PET, quantitative EEG and cognitive evoked potential using an auditory oddball paradigm were performed in minimally conscious state (MCS) and vegetative state (VS) patient.

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To explore whether the presence of an event-related potential (ERP) "global effect" (GE+)-that corresponds to a correlate of conscious processing in the local-global auditory task-predicts behaviorally overt consciousness recovery in a large cohort of patients suffering from disorders of consciousness (DOC). We conducted a prospective study on all DOC patients evaluated during the 2009-2018 period. Behavioral examination included Coma Recovery Scale-Revised (CRS-R) scores and bedside high-density EEG recordings.

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Predicting the functional recovery of patients with severe neurological condition due to coronavirus disease 2019 (COVID-19) is a challenging task. Only limited outcome data are available, the pathophysiology is poorly understood, and the time-course of recovery is still largely unknown. Here, we report the case of a patient with COVID-19 associated encephalitis presenting as a prolonged state of unresponsiveness for two months, who finally fully recovered consciousness, functional communication, and autonomy after immunotherapy.

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Neurological examination of non-communicating patients relies on a few decisive items that enable the crucial distinction between vegetative state (VS)-also coined unresponsive wakefulness syndrome (UWS)-and minimally conscious state. Over the past 10 years, this distinction has proven its diagnostic value as well as its important prognostic value on consciousness recovery. However, clinicians are currently limited by three factors: (i) the current behavioural repertoire of minimally conscious state items is limited and restricted to a few cognitive domains in the goldstandard revised version of the Coma Recovery Scale; (ii) a proportion of ∼15-20% clinically VS/UWS patients are actually in a richer state than VS/UWS as evidenced by functional brain imaging; and (iii) the neurophysiological and cognitive interpretation of each minimally conscious state item is still unclear and debated.

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Severe brain injuries can lead to long-lasting disorders of consciousness (DoC) such as vegetative state/unresponsive wakefulness syndrome (VS/UWS) or minimally conscious state (MCS). While behavioral assessment remains the gold standard to determine conscious state, EEG has proven to be a promising complementary tool to monitor the effect of new therapeutics. Encouraging results have been obtained with invasive electrical stimulation of the brain, and recent studies identified transcranial direct current stimulation (tDCS) as an effective approach in randomized controlled trials.

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Background: Endovascular techniques have proven beneficial in the treatment of aneurysmal subarachnoid hemorrhage (aSAH), but with high risk of arterial clotting, emboli and dissection. Platelet activation and alterations in hemostasis may contribute to these complications. We investigated platelet activation and aggregation pathways in aSAH patients who underwent endovascular treatment.

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