Consciousness: A Neurological Perspective

Cavanna, Andrea E.; Shah, S U; Eddy, Clare M.; Williams, Adrian; Rickards, Hugh

doi:10.1155/2011/645159

Cited by 44 publications

(14 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The corneal reflex will be absent with effective mechanical and electrical stunning [ 19 ]. Generalized seizures, while unpleasant to watch, are associated with complete loss of awareness and consciousness [ 20 ].…”

Section: Literature Reviewmentioning

confidence: 99%

Physiologic Measures of Animal Stress during Transitional States of Consciousness

Meyer¹

2015

Animals

View full text Add to dashboard Cite

Simple SummaryThe humaneness, and therefore suitability, of any particular agent or method used to produce unconsciousness in animals, whether for anesthesia, euthanasia, humane slaughter, or depopulation, depends on the experience of pain or distress prior to loss of consciousness. Commonly reported physiologic measures of animal stress, including physical movement and vocalization, heart rate and ECG, electroencephalographic activity, and plasma and neuronal stress markers are discussed within this context.AbstractDetermination of the humaneness of methods used to produce unconsciousness in animals, whether for anesthesia, euthanasia, humane slaughter, or depopulation, relies on our ability to assess stress, pain, and consciousness within the contexts of method and application. Determining the subjective experience of animals during transitional states of consciousness, however, can be quite difficult; further, loss of consciousness with different agents or methods may occur at substantially different rates. Stress and distress may manifest behaviorally (e.g., overt escape behaviors, approach-avoidance preferences [aversion]) or physiologically (e.g., movement, vocalization, changes in electroencephalographic activity, heart rate, sympathetic nervous system [SNS] activity, hypothalamic-pituitary axis [HPA] activity), such that a one-size-fits-all approach cannot be easily applied to evaluate methods or determine specific species applications. The purpose of this review is to discuss methods of evaluating stress in animals using physiologic methods, with emphasis on the transition between the conscious and unconscious states.

show abstract

Section: Literature Reviewmentioning

confidence: 99%

Physiologic Measures of Animal Stress during Transitional States of Consciousness

Meyer¹

2015

Animals

View full text Add to dashboard Cite

show abstract

“…The physiological candidate that might play a key role in consciousness is neural activity synchronised in the gamma frequency range (25 – 50 Hz), mostly close to 40 Hz between the thalamic and cortical structures (Llinas and Pare, 1991[132]; Cavanna et al ., 2011[31]). These are known as the 40 Hz thalamocortical oscillations and may be likely candidates for the binding problem (Singer and Gray, 1995[201]).…”

Section: Neuronal Models Of Consciousnessmentioning

confidence: 99%

Towards an integrative theory of consciousness: Part 1 (Neurobiological and cognitive models)

Sousa¹

2013

Mens Sana Monogr

View full text Add to dashboard Cite

The study of consciousness is poised today at interesting crossroads. There has been a surge of research into various neurobiological underpinnings of consciousness in the past decade. The present article looks at the theories regarding this complex phenomenon, especially the ones that neurobiology, cognitive neuroscience and cognitive psychology have to offer. We will first discuss the origin and etymology of word consciousness and its usage. Neurobiological correlates of consciousness are discussed with structures like the ascending reticular activating system, the amygdala, the cerebellum, the thalamus, the frontoparietal circuits, the prefrontal cortex and the precuneus. The cellular and microlevel theories of consciousness and cerebral activity at the neuronal level contributing to consciousness are highlighted, along with the various theories posited in this area. The role of neuronal assemblies and circuits along with firing patterns and their ramifications for the understanding of consciousness are discussed. A section on the role of anaesthesia and its links to consciousness is presented, along with details of split-brain studies in consciousness and altered states of awareness, including the vegetative states. The article finally discusses the progress cognitive psychology has made in identifying and theorising various perspectives of consciousness, perceptual awareness and conscious processing. Both recent and past researches are highlighted. The importance and salient features of each theory are discussed along with the pitfalls, if present. A need for integration of various theories to understand consciousness from a holistic perspective is stressed, to enable one to reach a theory that explains the ultimate neurobiology of consciousness.

show abstract

“…Attaining an accurate diagnosis remains one of the most challenging tasks with patients with Disorders of Consciousness (DOC) in the acute phase; an accurate diagnosis is crucial for prognosis validity because it influences medical management in terms of therapeutic choices and end-of-life decisions. Disorders of consciousness include a wide range of medical conditions in which patients present a global inability to interact with their environment in terms of wakefulness and awareness [ 1 ]. Among the broad nosology of DOC [ 2 ], three main ascending levels have been clinically identified according to behavioural criteria: Coma [ 3 ], Unresponsive Wakefulness Syndrome (UWS) [ 4 ], and a Minimally Conscious State (MCS) [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Outcome Prediction of Consciousness Disorders in the Acute Stage Based on a Complementary Motor Behavioural Tool

et al. 2016

View full text Add to dashboard Cite

IntroductionAttaining an accurate diagnosis in the acute phase for severely brain-damaged patients presenting Disorders of Consciousness (DOC) is crucial for prognostic validity; such a diagnosis determines further medical management, in terms of therapeutic choices and end-of-life decisions. However, DOC evaluation based on validated scales, such as the Revised Coma Recovery Scale (CRS-R), can lead to an underestimation of consciousness and to frequent misdiagnoses particularly in cases of cognitive motor dissociation due to other aetiologies. The purpose of this study is to determine the clinical signs that lead to a more accurate consciousness assessment allowing more reliable outcome prediction.MethodsFrom the Unit of Acute Neurorehabilitation (University Hospital, Lausanne, Switzerland) between 2011 and 2014, we enrolled 33 DOC patients with a DOC diagnosis according to the CRS-R that had been established within 28 days of brain damage. The first CRS-R assessment established the initial diagnosis of Unresponsive Wakefulness Syndrome (UWS) in 20 patients and a Minimally Consciousness State (MCS) in the remaining13 patients. We clinically evaluated the patients over time using the CRS-R scale and concurrently from the beginning with complementary clinical items of a new observational Motor Behaviour Tool (MBT). Primary endpoint was outcome at unit discharge distinguishing two main classes of patients (DOC patients having emerged from DOC and those remaining in DOC) and 6 subclasses detailing the outcome of UWS and MCS patients, respectively. Based on CRS-R and MBT scores assessed separately and jointly, statistical testing was performed in the acute phase using a non-parametric Mann-Whitney U test; longitudinal CRS-R data were modelled with a Generalized Linear Model.ResultsFifty-five per cent of the UWS patients and 77% of the MCS patients had emerged from DOC. First, statistical prediction of the first CRS-R scores did not permit outcome differentiation between classes; longitudinal regression modelling of the CRS-R data identified distinct outcome evolution, but not earlier than 19 days. Second, the MBT yielded a significant outcome predictability in the acute phase (p<0.02, sensitivity>0.81). Third, a statistical comparison of the CRS-R subscales weighted by MBT became significantly predictive for DOC outcome (p<0.02).DiscussionThe association of MBT and CRS-R scoring improves significantly the evaluation of consciousness and the predictability of outcome in the acute phase. Subtle motor behaviour assessment provides accurate insight into the amount and the content of consciousness even in the case of cognitive motor dissociation.

show abstract

Consciousness: A Neurological Perspective

Cited by 44 publications

References 66 publications

Physiologic Measures of Animal Stress during Transitional States of Consciousness

Physiologic Measures of Animal Stress during Transitional States of Consciousness

Towards an integrative theory of consciousness: Part 1 (Neurobiological and cognitive models)

Outcome Prediction of Consciousness Disorders in the Acute Stage Based on a Complementary Motor Behavioural Tool

Contact Info

Product

Resources

About