Consciousness after death

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Smierc ("Death"), a 1902 painting by Jacek Malczewski Jacek Malczewski, Smierc.jpg
Śmierć ("Death"), a 1902 painting by Jacek Malczewski

Consciousness after death is a common theme in society and culture, and the belief in some form of life after death is a feature of many religions. However, scientific research has established that the physiological functioning of the brain, the cessation of which defines brain death, is closely connected to mental states.

Contents

Neuroscience

Neuroscience is a large interdisciplinary field founded on the premise that all of behavior and all of the cognitive processes that constitute the mind have their origin in the structure and function of the nervous system, especially in the brain. According to this view, the mind can be regarded as a set of operations carried out by the brain. [1] [2] [3] [4] [5]

Many lines of evidence support this view, for example:

Pharmacological manipulation uses various drugs which alter neural activity by interfering with neurotransmission, resulting in alterations in perception, mood, consciousness, cognition, and behavior. Psychoactive drugs are divided into different groups according to their pharmacological effects; euphoriants which tend to induce feelings of euphoria, stimulants that induce temporary improvements in either mental or physical functions, depressants that depress or reduce arousal or stimulation and hallucinogens which can cause hallucinations, perception anomalies, and other substantial subjective changes in thoughts, emotion, and consciousness.
Electrical and magnetical stimulations uses various electrical methods and techniques like transcranial magnetic stimulation. In a comprehensive review of electrical brain stimulation (EBS) results obtained from the last 100 years neuroscientist Aslihan Selimbeyoglu and neurologist Josef Parvizi compiled a list of many different subjective experiential phenomena and behavioral changes that can be caused by electrical stimulation of the cerebral cortex or subcortical nuclei in awake and conscious human subjects. [9]
Optogenetic manipulation uses light to control neurons which have been genetically sensitised to light.[ citation needed ]

Death

Death is the permanent end of all biological functions that sustain a living organism. It is no longer defined as the cessation of heartbeat (cardiac arrest) and breathing, as CPR and prompt defibrillation can sometimes restart both. In modern medicine, when a definition of the moment of death is required, doctors and coroners usually turn to "brain death" or "biological death" to define a person as being dead; brain death being defined as the complete and irreversible loss of brain function (including involuntary activity necessary to sustain life). [15] [16] [17] [18]

Near-death experience (NDE)

A near-death experience (NDE) is a personal experience associated with impending death, encompassing multiple possible sensations. Some explanations from neuroscience hypothesize the NDE to be a hallucinatory state caused by various neurological factors such as cerebral anoxia, hypercarbia, abnormal activity in the temporal lobes and brain damage, though the exact nature of such experiences is not universally agreed upon. [19] [20]

Dr. Bruce Greyson, an American professor who specializes in Near Death Experiences said in a study that patients have a stop in brain activity but still have Near Death Experience. [21]

See also

Related Research Articles

<span class="mw-page-title-main">Consciousness</span> Awareness of existence

Consciousness, at its simplest, is awareness of internal and external existence. However, its nature has led to millennia of analyses, explanations and debate by philosophers, theologians, and scientists. Opinions differ about what exactly needs to be studied or even considered consciousness. In some explanations, it is synonymous with the mind, and at other times, an aspect of mind. In the past, it was one's "inner life", the world of introspection, of private thought, imagination and volition. Today, it often includes any kind of cognition, experience, feeling or perception. It may be awareness, awareness of awareness, metacognition, or self-awareness either continuously changing or not. The disparate range of research, notions and speculations raises a curiosity about whether the right questions are being asked.

<span class="mw-page-title-main">Cognitive neuroscience</span> Scientific field

Cognitive neuroscience is the scientific field that is concerned with the study of the biological processes and aspects that underlie cognition, with a specific focus on the neural connections in the brain which are involved in mental processes. It addresses the questions of how cognitive activities are affected or controlled by neural circuits in the brain. Cognitive neuroscience is a branch of both neuroscience and psychology, overlapping with disciplines such as behavioral neuroscience, cognitive psychology, physiological psychology and affective neuroscience. Cognitive neuroscience relies upon theories in cognitive science coupled with evidence from neurobiology, and computational modeling.

The following outline is provided as an overview of and topical guide to neuroscience:

<span class="mw-page-title-main">Functional neuroimaging</span>

Functional neuroimaging is the use of neuroimaging technology to measure an aspect of brain function, often with a view to understanding the relationship between activity in certain brain areas and specific mental functions. It is primarily used as a research tool in cognitive neuroscience, cognitive psychology, neuropsychology, and social neuroscience.

Physiological psychology is a subdivision of behavioral neuroscience that studies the neural mechanisms of perception and behavior through direct manipulation of the brains of nonhuman animal subjects in controlled experiments. This field of psychology takes an empirical and practical approach when studying the brain and human behavior. Most scientists in this field believe that the mind is a phenomenon that stems from the nervous system. By studying and gaining knowledge about the mechanisms of the nervous system, physiological psychologists can uncover many truths about human behavior. Unlike other subdivisions within biological psychology, the main focus of psychological research is the development of theories that describe brain-behavior relationships.

<span class="mw-page-title-main">Claustrum</span> Structure in the brain

The claustrum is a thin sheet of neurons and supporting glial cells, that connects to the cerebral cortex and subcortical regions including the amygdala, hippocampus and thalamus of the brain. It is located between the insular cortex laterally and the putamen medially, encased by the extreme and external capsules respectively. Blood to the claustrum is supplied by the middle cerebral artery. It is considered to be the most densely connected structure in the brain, and thus hypothesized to allow for the integration of various cortical inputs such as vision, sound and touch, into one experience. Other hypotheses suggest that the claustrum plays a role in salience processing, to direct attention towards the most behaviorally relevant stimuli amongst the background noise. The claustrum is difficult to study given the limited number of individuals with claustral lesions and the poor resolution of neuroimaging.

In the philosophy of mind, neuroscience, and cognitive science, a mental image is an experience that, on most occasions, significantly resembles the experience of "perceiving" some object, event, or scene but occurs when the relevant object, event, or scene is not actually present to the senses. There are sometimes episodes, particularly on falling asleep and waking up, when the mental imagery may be dynamic, phantasmagoric, and involuntary in character, repeatedly presenting identifiable objects or actions, spilling over from waking events, or defying perception, presenting a kaleidoscopic field, in which no distinct object can be discerned. Mental imagery can sometimes produce the same effects as would be produced by the behavior or experience imagined.

<span class="mw-page-title-main">Behavioral neuroscience</span> Field of study

Behavioral neuroscience, also known as biological psychology, biopsychology, or psychobiology, is the application of the principles of biology to the study of physiological, genetic, and developmental mechanisms of behavior in humans and other animals.

<span class="mw-page-title-main">Antonio Damasio</span> Portuguese neuroscientist (born 1944)

Antonio Damasio is a Portuguese neuroscientist. He is currently the David Dornsife Chair in Neuroscience, as well as Professor of Psychology, Philosophy, and Neurology, at the University of Southern California, and, additionally, an adjunct professor at the Salk Institute. He was previously the chair of neurology at the University of Iowa for 20 years. Damasio heads the Brain and Creativity Institute, and has authored several books: his work, Self Comes to Mind: Constructing the Conscious Brain (2010), explores the relationship between the brain and consciousness. Damasio's research in neuroscience has shown that emotions play a central role in social cognition and decision-making.

Neurotechnology encompasses any method or electronic device which interfaces with the nervous system to monitor or modulate neural activity.

Neuroergonomics is the application of neuroscience to ergonomics. Traditional ergonomic studies rely predominantly on psychological explanations to address human factors issues such as: work performance, operational safety, and workplace-related risks. Neuroergonomics, in contrast, addresses the biological substrates of ergonomic concerns, with an emphasis on the role of the human nervous system.

Helen S. Mayberg, is an American neurologist. Mayberg is known in particular for her work delineating abnormal brain function in patients with major depression using functional neuroimaging. This work led to the first pilot study of deep brain stimulation (DBS), a reversible method of selective modulation of a specific brain circuit, for patients with treatment-resistant depression. As of August 2019, she has published 211 original peer-reviewed articles, 31 books and book chapters, and acted as principal investigator on 24 research grants. Mayberg is coinventor with Andres Lozano of “Method for Treating Depression Mood Disorders and Anxiety Disorders using Neuromodulation,” US patent 2005/0033379A1. St. Jude Medical Neuromodulation licensed her intellectual property to develop Subcallosal Cingulate Deep Brain Stimulation for Treatment-Resistant Unipolar and Bipolar Depression for the treatment of severe depression. As of 2018, Mayberg holds positions as Professor of Neurology and Neurosurgery and Professor, Psychiatry and Neuroscience, both at Mount Sinai Medical School, and Professor of Psychiatry, Emory University; Emory University Hospital. Since 2018, she has served as Director, Nash Family Center for Advanced Circuit Therapeutics at the Icahn School of Medicine at Mount Sinai.

Neurophysics is the branch of biophysics dealing with the development and use of physical methods to gain information about the nervous system. Neurophysics is an interdisciplinary science using physics and combining it with other neurosciences to better understand neural processes. The methods used include the techniques of experimental biophysics and other physical measurements such as EEG mostly to study electrical, mechanical or fluidic properties, as well as theoretical and computational approaches. The term "neurophysics" is a portmanteau of "neuron" and "physics".

<span class="mw-page-title-main">Neural correlates of consciousness</span> Neuronal events sufficient for a specific conscious percept

The neural correlates of consciousness (NCC) are the minimal set of neuronal events and mechanisms sufficient for the occurrence of the mental states to which they are related. Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena; that is, neural changes which necessarily and regularly correlate with a specific experience. The set should be minimal because, under the materialist assumption that the brain is sufficient to give rise to any given conscious experience, the question is which of its components are necessary to produce it.

<span class="mw-page-title-main">Electrical brain stimulation</span> Form of electrotherapy

Electrical brain stimulation (EBS), also referred to as focal brain stimulation (FBS), is a form of electrotherapy used as a technique in research and clinical neurobiology to stimulate a neuron or neural network in the brain through the direct or indirect excitation of its cell membrane by using an electric current. EBS is used for research or for therapeutic purposes.

Some of the research that is conducted in the field of psychology is more "fundamental" than the research conducted in the applied psychological disciplines, and does not necessarily have a direct application. The subdisciplines within psychology that can be thought to reflect a basic-science orientation include biological psychology, cognitive psychology, neuropsychology, and so on. Research in these subdisciplines is characterized by methodological rigor. The concern of psychology as a basic science is in understanding the laws and processes that underlie behavior, cognition, and emotion. Psychology as a basic science provides a foundation for applied psychology. Applied psychology, by contrast, involves the application of psychological principles and theories yielded up by the basic psychological sciences; these applications are aimed at overcoming problems or promoting well-being in areas such as mental and physical health and education.

The following outline is provided as an overview of and topical guide to brain mapping:

The following outline is provided as an overview of and topical guide to the human brain:

Social cognitive neuroscience is the scientific study of the biological processes underpinning social cognition. Specifically, it uses the tools of neuroscience to study "the mental mechanisms that create, frame, regulate, and respond to our experience of the social world". Social cognitive neuroscience uses the epistemological foundations of cognitive neuroscience, and is closely related to social neuroscience. Social cognitive neuroscience employs human neuroimaging, typically using functional magnetic resonance imaging (fMRI). Human brain stimulation techniques such as transcranial magnetic stimulation and transcranial direct-current stimulation are also used. In nonhuman animals, direct electrophysiological recordings and electrical stimulation of single cells and neuronal populations are utilized for investigating lower-level social cognitive processes.

References

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Further reading