Spectrum Model of Brain and Consciousness

2018 ◽  
pp. 79-104
Author(s):  
Georg Northoff
Keyword(s):  
Empirical Evidence ◽  
Vegetative State ◽  
Disorders Of Consciousness ◽  
Loss Of Consciousness ◽  
Hybrid Nature ◽  
Level Of Consciousness ◽  
Spectrum Model ◽  
Spatiotemporal Integration

Is the spectrum model of brain and its assumption of the hybrid nature of stimulus-induced activity relevant for consciousness? That is the focus in the present chapter. I here present various lines of empirical evidence focusing on disorders of consciousness like vegetative state, anesthesia, and sleep. These findings suggest that the loss of consciousness in vegetative state, anesthesia, and sleep is characterized by the loss of the hybrid nature of stimulus-induced activity which shifts more towards the passive pole. This lets me suppose that the hybrid nature of stimulus-induced activity including its spatiotemporal integration as postulated in the spectrum model is central for the level of consciousness. I therefore conclude that the spectrum model of brain is relevant for consciousness.

Interaction Model of Brain and Consciousness

2018 ◽  
pp. 105-126
Author(s):  
Georg Northoff
Keyword(s):  
Empirical Evidence ◽  
Vegetative State ◽  
Interaction Model ◽  
Necessary Condition ◽  
Additive Interaction ◽  
Fine Grained ◽  
Nancy Cartwright ◽  
Level Of Consciousness ◽  
The Brain

In addition to the spectrum model, I also introduced an interaction model to characterize the brain’s neural activity (chapter 2). Is the interaction model of brain also relevant for consciousness? That is the focus in the present chapter. I here present various lines of empirical evidence focusing on disorders of consciousness like vegetative state, anesthesia, and sleep. Based on empirical evidence, I show that the degree of non-additive interaction between spontaneous and stimulus-induced activity indexes the level of consciousness in a seemingly rather fine-grained way; for that reason, it may be considered a neural correlate of the level of consciousness, i.e., NCC. In contrast, the spontaneous activity and its spatiotemporal structure is rather a necessary condition of possible consciousness, that is, a neural predisposition of consciousness (NPC). The concept of NPC is further enriched by the concept of capacities for which I recruit Nancy Cartwright. I suggest that the brain’s non-additive interaction including the subsequent association of stimulus-induced activity with consciousness is based on the spontaneous activity’s capacity. Since that very same capacity, operating as NPC, can be traced to the spontaneous activity’s spatiotemporal features, I speak of “spatiotemporal capacity”. I conclude that the empirical data suggest a capacity-based approach (rather than law-based approach) to the brain and how it is related to consciousness.

scholarly journals Effect of Retinohypothalamic Tract Dysfunction on Melatonin Level in Patients with Chronic Disorders of Consciousness

2021 ◽  
Vol 11 (5) ◽  
pp. 559
Author(s):  
Mikhail Kanarskii ◽  
Julia Nekrasova ◽  
Svetlana Vitkovskaya ◽  
Pranil Pradhan ◽  
Sergey Peshkov ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Direct Relationship ◽  
Disorders Of Consciousness ◽  
Melatonin Level ◽  
Melatonin Secretion ◽  
Peripheral Part ◽  
Level Of Consciousness ◽  
Retinohypothalamic Tract ◽  
Chronic Disorders ◽  
Chronic Disorders Of Consciousness

Objective: The aim of this study is to compare the secretion level of nocturnal melatonin and the characteristics of the peripheral part of the visual analyzer in patients with chronic disorders of consciousness (DOC). Materials and Methods: We studied the level of melatonin in 22 patients with chronic DOC and in 11 healthy volunteers. The fundus condition was assessed using the ophthalmoscopic method. Results: The average level of nocturnal melatonin in patients with DOC differed by 80% from the level of indole in healthy volunteers. This reveals a direct relationship between etiology, the level of consciousness, gaze fixation, coma recovery scale-revised score and the level of melatonin secretion. Examination by an ophthalmologist revealed a decrease in the macular reflex in a significant number of DOC patients, which in turn correlates negatively with the time from brain injury and positively with low values of nocturnal melatonin.

Evaluation of structural variations in the pituitary gland, hormonal status and laboratory markers of the central nervous system functioning in patients with chronic disorders of consciousness

2021 ◽  
Vol 70 (5) ◽  
pp. 23-36
Author(s):  
Ekaterina A. Kondratyeva ◽  
Alina O. Ivanova ◽  
Maria I. Yarmolinskaya ◽  
Elena G. Potyomkina ◽  
Natalya V. Dryagina ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Blood Serum ◽  
Minimally Conscious State ◽  
Conscious State ◽  
Disorders Of Consciousness ◽  
Unresponsive Wakefulness Syndrome ◽  
Level Of Consciousness ◽  
Chronic Disorders ◽  
Minimally Conscious ◽  
Chronic Disorders Of Consciousness

BACKGROUND: Consciousness is the state of being awake and aware of oneself and the environment. The disorders of consciousness result from pathologies that impair awareness. The development of effective comprehensive personalized interventions contributing to the recovery of consciousness in patients with chronic disorders of consciousness is one of the most pressing and challenging tasks in modern rehabilitation. AIM: The aim of this study was to understand structural problems of the pituitary gland, blood levels of gonadotropins and melatonin as well as brain damage markers in the blood and cerebrospinal fluid in patients with chronic disorders of consciousness and to analyze the levels of the above markers among different groups of patients depending on the level of impaired consciousness. MATERIALS AND METHODS: We examined 61 chronic disorders of consciousness patients and identified three groups depending on the level of consciousness including 24 patients with unresponsive wakefulness syndrome, 24 patients with a minus minimally conscious state, and 13 patients with minimally conscious state plus. We performed magnetic resonance imaging of chiasmatic-sellar region and determined blood serum levels of follicle-stimulating and luteinizing hormones and melatonin, as well as urinary level of 6-sulfatoxymelatonin and the content of brain derived neurotrophic factor (BDNF), apoptosis antigen (APO-1), FasL, glutamate, and S100 protein in the blood serum and cerebrospinal fluid. RESULTS: The patients were examined in the age ranging from 15 to 61 years old. Patient groups were homogeneous by the level of consciousness in terms of age and duration of chronic disorders of consciousness by the time of examination. The patients did not differ in the pituitary volume regardless of the level of consciousness. No significant differences were found between the groups with different levels of consciousness when studying the levels of melatonin in the blood serum and its metabolite in the urine. A peak in melatonin secretion was detected at 3 a.m. in 54.5 % of the patients, which can be considered as a favorable prognostic marker for further recovery of consciousness. Hypogonadotropic ovarian failure was found in 34 % of the patients, with normogonadotropic ovarian failure in the remaining patients. Serum APO-1 and BDNF levels were significantly higher in patients with minimally conscious state relative to those with unresponsive wakefulness syndrome. Significantly lower levels of glutamate in the cerebrospinal fluid were detected in women with unresponsive wakefulness syndrome compared to patients with minimally conscious state. CONCLUSIONS: Further in-depth examination and accumulation of data on patients with chronic disorders of consciousness may provide an opportunity to identify highly informative markers for predicting outcomes and to develop new effective approaches to rehabilitation of consciousness in this category of patients.

scholarly journals Observations on the Ethical and Social Aspects of Disorders of Consciousness

2010 ◽  
Vol 37 (6) ◽  
pp. 758-768 ◽  
Author(s):  
Eric Racine ◽  
Catherine Rodrigue ◽  
James L. Bernat ◽  
Richard Riopelle ◽  
Sam D. Shemie
Keyword(s):  
Life Support ◽  
Functional Neuroimaging ◽  
Vegetative State ◽  
Clinical Care ◽  
Disorders Of Consciousness ◽  
Artificial Nutrition ◽  
Artificial Nutrition And Hydration ◽  
Neuroscience Research ◽  
Nutrition And Hydration ◽  
Unconscious Patients

AbstractThe care of chronically unconscious patients raises vexing medical, ethical, and social questions concerning diagnosis, prognosis, communication with family members, and decision making, including the withdrawal of life support. We provide updates on major controversies surrounding disorders of consciousness. Issues such as withdrawal of artificial nutrition and hydration – which had been considered “settled” by many in the medical, legal and ethical communities – have resurfaced under the pressure of social groups and religious authorities. Some assumptions about the level of awareness and the prognosis of vegetative state and minimal conscious patients are questioned by advances in clinical care because of insights produced by neuroscience research techniques, particularly functional neuroimaging. Both the clinical and neuroscience dimensions of disorders of consciousness raise complex issues such as resource allocation and high levels of diagnostic inaccuracies (at least, for the vegetative state). We conclude by highlighting areas needing further research and collaboration.

scholarly journals Practice guideline update recommendations summary: Disorders of consciousness

Neurology ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 450-460 ◽  
Author(s):  
Joseph T. Giacino ◽  
Douglas I. Katz ◽  
Nicholas D. Schiff ◽  
John Whyte ◽  
Eric J. Ashman ◽  
...  
Keyword(s):  
Vegetative State ◽  
Persistent Vegetative State ◽  
Minimally Conscious State ◽  
Conscious State ◽  
Case Definition ◽  
Disorders Of Consciousness ◽  
Family Counseling ◽  
Delphi Consensus ◽  
Post Injury ◽  
Term Care

ObjectiveTo update the 1995 American Academy of Neurology (AAN) practice parameter on persistent vegetative state and the 2002 case definition on minimally conscious state (MCS) and provide care recommendations for patients with prolonged disorders of consciousness (DoC).MethodsRecommendations were based on systematic review evidence, related evidence, care principles, and inferences using a modified Delphi consensus process according to the AAN 2011 process manual, as amended.RecommendationsClinicians should identify and treat confounding conditions, optimize arousal, and perform serial standardized assessments to improve diagnostic accuracy in adults and children with prolonged DoC (Level B). Clinicians should counsel families that for adults, MCS (vs vegetative state [VS]/unresponsive wakefulness syndrome [UWS]) and traumatic (vs nontraumatic) etiology are associated with more favorable outcomes (Level B). When prognosis is poor, long-term care must be discussed (Level A), acknowledging that prognosis is not universally poor (Level B). Structural MRI, SPECT, and the Coma Recovery Scale–Revised can assist prognostication in adults (Level B); no tests are shown to improve prognostic accuracy in children. Pain always should be assessed and treated (Level B) and evidence supporting treatment approaches discussed (Level B). Clinicians should prescribe amantadine (100–200 mg bid) for adults with traumatic VS/UWS or MCS (4–16 weeks post injury) to hasten functional recovery and reduce disability early in recovery (Level B). Family counseling concerning children should acknowledge that natural history of recovery, prognosis, and treatment are not established (Level B). Recent evidence indicates that the term chronic VS/UWS should replace permanent VS, with duration specified (Level B). Additional recommendations are included.

scholarly journals Stimulation of the Angular Gyrus Improves the Level of Consciousness

2019 ◽  
Vol 9 (5) ◽  
pp. 103 ◽  
Author(s):  
Liudmila Legostaeva ◽  
Alexandra Poydasheva ◽  
Elizaveta Iazeva ◽  
Dmitry Sinitsyn ◽  
Dmitry Sergeev ◽  
...  
Keyword(s):  
Repetitive Transcranial Magnetic Stimulation ◽  
Vegetative State ◽  
Minimally Conscious State ◽  
Conscious State ◽  
Angular Gyrus ◽  
New Approach ◽  
Promising Tool ◽  
Level Of Consciousness ◽  
Minimally Conscious ◽  
Left Angular Gyrus

Background: Navigated repetitive transcranial magnetic stimulation (rTMS) is a promising tool for neuromodulation. In previous studies it has been shown that the activity of the default mode network (DMN) areas, particularly of its key region—the angular gyrus—is positively correlated with the level of consciousness. Our study aimed to explore the effect of rTMS of the angular gyrus as a new approach for disorders of consciousness (DOC) treatment; Methods: A 10-session 2-week high-frequency rTMS protocol was delivered over the left angular gyrus in 38 DOC patients with repeated neurobehavioral assessments obtained at baseline and in 2 days after the stimulation course was complete; Results: 20 Hz-rTMS over left angular gyrus improved the coma recovery scale revised (CRS-R) total score in minimally conscious state (MCS) patients. We observed no effects in vegetative state (VS) patients; and Conclusions: The left angular gyrus is likely to be effective target for rTMS in patients with present signs of consciousness.

scholarly journals Covert Cognition in Disorders of Consciousness: A Meta-Analysis

2020 ◽  
Vol 10 (12) ◽  
pp. 930
Author(s):  
Caroline Schnakers ◽  
Michaela Hirsch ◽  
Enrique Noé ◽  
Roberto Llorens ◽  
Nicolas Lejeune ◽  
...  
Keyword(s):  
Observational Studies ◽  
Functional Neuroimaging ◽  
Vegetative State ◽  
Meta Analysis ◽  
Minimally Conscious State ◽  
Conscious State ◽  
Demographic Variables ◽  
Disorders Of Consciousness ◽  
Minimally Conscious ◽  
Increase Sample Size

Covert cognition in patients with disorders of consciousness represents a real diagnostic conundrum for clinicians. In this meta-analysis, our main objective was to identify clinical and demographic variables that are more likely to be associated with responding to an active paradigm. Among 2018 citations found on PubMed, 60 observational studies were found relevant. Based on the QUADAS-2, 49 studies were considered. Data from 25 publications were extracted and included in the meta-analysis. Most of these studies used electrophysiology as well as counting tasks or mental imagery. According to our statistical analysis, patients clinically diagnosed as being in a vegetative state and in a minimally conscious state minus (MCS−) show similar likelihood in responding to active paradigm and responders are most likely suffering from a traumatic brain injury. In the future, multi-centric studies should be performed in order to increase sample size, with similar methodologies and include structural and functional neuroimaging in order to identify cerebral markers related to such a challenging diagnosis.

Beyond Parents: Collective Duties to Children

2020 ◽  
pp. 135-146
Author(s):  
Timothy Fowler ◽  
Timothy Fowler
Keyword(s):  
Empirical Evidence ◽  
Moral Duty ◽  
Special Duties

In this chapter, I consider duties non-parents might have to children. I consider empirical evidence which suggests that parents matter less for children than is commonly assumed, and that other members of society matter more. I suggest that this influence on children generates duties to the children that are similar- albeit weaker- to those of parents. All members of society are responsible for the content of children’s character and this impact brings duties to ensure society is not harmful to the child. Further, the intertwined nature of children’s lives means that special duties to one child transfer to others. The implication is that the perfectionist duties explored in chapter 11 apply not just to parents but to all citizens, who have a moral duty to change their conduct in ways that will further the wellbeing of children.

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