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Friday, October 26, 2018

Antonio Damasio

From Wikipedia, the free encyclopedia
Antonio Damasio
António Damásio no Fronteiras do Pensamento Porto Alegre 2013 cropped.png
Damasio at the Fronteiras do Pensamento conference in 2013.
 
Born 25 February 1944 (age 74)
Lisbon, Portugal
Nationality U.S. and Portuguese
Alma mater University of Lisbon
Spouse(s) Hanna Damasio
Awards Pessoa Prize (1992)
Golden Brain Award (1995)
Prince of Asturias Prize (2005)
Honda Prize (2010)
Grawemeyer Award in Psychology (2014)
Scientific career
Fields Cognitive Neuroscience
Institutions University of Southern California
Thesis Perturbações neurológicas da linguagem e de outras funções simbólicas (1974)
Author abbrev. (botany) 1333

Antonio Damasio (Portuguese: António Damásio) is a Portuguese-American neuroscientist. He is currently the David Dornsife Professor of Neuroscience, Psychology and Philosophy at the University of Southern California and an adjunct professor at the Salk Institute. Damasio heads the Brain and Creativity Institute, and has authored several books: his most recent 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.

Life and work

Damasio studied medicine at the University of Lisbon Medical School, where he also did his neurological residency and completed his doctorate. For part of his studies, he researched behavioral neurology under the supervision of Norman Geschwind of the Aphasia Research Center in Boston.
Damasio's main field is neurobiology, especially the neural systems which underlie emotion, decision-making, memory, language and consciousness. Damasio might believe that emotions play a critical role in high-level cognition—an idea counter to dominant 20th-century views in psychology, neuroscience and philosophy.

Damasio in 2008

Damasio formulated the somatic marker hypothesis, a theory about how emotions and their biological underpinnings are involved in decision-making (both positively and negatively, and often non-consciously). Emotions provide the scaffolding for the construction of social cognition and are required for the self processes which undergird consciousness. "Damasio provides a contemporary scientific validation of the linkage between feelings and the body by highlighting the connection between mind and nerve cells ... this personalized embodiment of mind."

The somatic marker hypothesis has inspired many neuroscience experiments carried out in laboratories in the U.S. and Europe, and has had a major impact in contemporary science and philosophy. Damasio has been named by the Institute for Scientific Information as one of the most highly cited researchers in the past decade. Current work on the biology of moral decisions, neuro-economics, social communication, and drug-addiction, has been strongly influenced by Damasio's hypothesis. An article published in the Archives of Scientific Psychology in 2014 named Damasio one of the 100 most eminent psychologist of the modern era. (Diener et al. Archives of Scientific Psychology, 2014, 2, 20–32). The June–July issue of Sciences Humaines included Damasio in its list of 50 key thinkers in the human sciences of the past two centuries.

Damasio also proposed that emotions are part of homeostatic regulation and are rooted in reward/punishment mechanisms. He recovered William James' perspective on feelings as a read-out of body states, but expanded it with an "as-if-body-loop" device which allows for the substrate of feelings to be simulated rather than actual (foreshadowing the simulation process later uncovered by mirror neurons). He demonstrated experimentally that the insular cortex is a critical platform for feelings, a finding that has been widely replicated, and he uncovered cortical and subcortical induction sites for human emotions, e.g. in ventromedial prefrontal cortex and amygdala. He also demonstrated that while the insular cortex plays a major role in feelings, it is not necessary for feelings to occur, suggesting that brain stem structures play a basic role in the feeling process.

He has continued to investigate the neural basis of feelings and demonstrated that although the insular cortex is a major substrate for this process it is not exclusive, suggesting that brain stem nuclei are critical platforms as well. He regards feelings as the necessary foundation of sentience.
In another development, Damasio proposed that the cortical architecture on which learning and recall depend involves multiple, hierarchically organized loops of axonal projections that converge on certain nodes out of which projections diverge to the points of origin of convergence (the convergence-divergence zones). This architecture is applicable to the understanding of memory processes and of aspects of consciousness related to the access of mental contents.

In The Feeling of What Happens, Damasio laid the foundations of the "enchainment of precedences": "the nonconscious neural signaling of an individual organism begets the protoself which permits core self and core consciousness, which allow for an autobiographical self, which permits extended consciousness. At the end of the chain, extended consciousness permits conscience.

Damasio's research depended significantly on establishing the modern human lesion method, an enterprise made possible by Hanna Damasio's structural neuroimaging/neuroanatomy work complemented by experimental neuroanatomy (with Gary Van Hoesen and Josef Parvizi), experimental neuropsychology (with Antoine Bechara, Ralph Adolphs, and Dan Tranel) and functional neuroimaging (with Kaspar Meyer, Jonas Kaplan, and Mary Helen Immordino-Yang). The experimental neuroanatomy work with Van Hoesen and Bradley Hyman led to the discovery of the disconnection of the hippocampus caused by neurofibrillary tangles in the entorhinal cortex of patients with Alzheimer's disease.

As a clinician, he and his collaborators have studied and treated disorders of behaviour and cognition, and movement disorders.

Damasio's books deal with the relationship between emotions and their brain substrates. His 1994 book, Descartes' Error: Emotion, Reason and the Human Brain, won the Science et Vie prize, was a finalist for the Los Angeles Times Book Award, and is translated in over 30 languages. It is regarded as one of the most influential books of the past two decades. His second book, The Feeling of What Happens: Body and Emotion in the Making of Consciousness, was named as one of the ten best books of 2001 by the New York Times Book Review, a Publishers Weekly Best Book of the Year, a Library Journal Best Book of the Year, and has over 30 foreign editions. Damasio's Looking for Spinoza: Joy, Sorrow, and the Feeling Brain, was published in 2003. In it, Damasio suggested that Spinoza's thinking foreshadowed discoveries in biology and neuroscience views on the mind-body problem and that Spinoza was a protobiologist. Damasio's latest book is Self Comes to Mind: Constructing the Conscious Brain. In it Damasio suggests that the self is the key to conscious minds and that feelings, from the kind he designates as primordial to the well-known feelings of emotion, are the basic elements in the construction of the protoself and core self. The book received the Corinne International Book Prize.

Damasio at Fronteiras do Pensamento (Frontiers of Thought) in 2013

Damasio is a member of the American Academy of Arts and Sciences, the National Academy of Medicine, the European Academy of Sciences and Arts. He is the recipient of several prizes, amongst them the Grawemeyer Award, the Honda Prize, the Prince of Asturias Award in Science and Technology and the Beaumont Medal from the American Medical Association, as well as honorary degrees from, most recently, the Sorbonne (Université Paris Descartes), shared with his wife Hanna Damasio. He has also received doctorates from the Universities of Aachen, Copenhagen, Leiden, Barcelona, Coimbra, Leuven and numerous others.

In 2013, the Escola Secundária António Damásio was dedicated in Lisbon.

He says he writes in the belief that "scientific knowledge can be a pillar to help humans endure and prevail."

He is married to Hanna Damasio, a prominent neuroscientist and frequent collaborator and co-author, who is a professor of neuroscience at the University of Southern California and the director of the Dornsife Neuroimaging Center.

In 2017 he was designated member of the Council of State of Portugal, replacing Antonio Guterres, the 9th Secretary-General of the United Nations.

Damasio additionally serves on the board of directors of the Berggruen Institute, and sits on the jury for the Berggruen Prize for Philosophy.

Selected bibliography

Books

  • Descartes' Error: Emotion, Reason, and the Human Brain, Putnam, 1994; revised Penguin edition, 2005
  • The Feeling of What Happens: Body and Emotion in the Making of Consciousness, Harcourt, 1999
  • Looking for Spinoza: Joy, Sorrow, and the Feeling Brain, Harcourt, 2003
  • Self Comes to Mind: Constructing the Conscious Brain, Pantheon, 2010. ISBN 978-1-5012-4695-1
  • The Strange Order of Things: Life, Feeling, and the Making of Cultures, Pantheon, 2018.

Selected articles

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Cognitive biology

From Wikipedia, the free encyclopedia
Cognitive biology is an emerging science that regards natural cognition as a biological function. It is based on the theoretical assumption that every organism—whether a single cell or multicellular—is continually engaged in systematic acts of cognition coupled with intentional behaviors, i.e., a sensory-motor coupling. That is to say, if an organism can sense stimuli in its environment and respond accordingly, it is cognitive. Any explanation of how natural cognition may manifest in an organism is constrained by the biological conditions in which its genes survives from one generation to the next. And since by Darwinian theory the species of every organism is evolving from a common root, three further elements of cognitive biology are required: (i) the study of cognition in one species of organism is useful, through contrast and comparison, to the study of another species’ cognitive abilities; (ii) it is useful to proceed from organisms with simpler to those with more complex cognitive systems, and (iii) the greater the number and variety of species studied in this regard, the more we understand the nature of cognition.

Overview

While cognitive science endeavors to explain human thought and the conscious mind, the work of cognitive biology is focused on the most fundamental process of cognition for any organism. In the past several decades, biologists have investigated cognition in organisms large and small, both plant and animal. “Mounting evidence suggests that even bacteria grapple with problems long familiar to cognitive scientists, including: integrating information from multiple sensory channels to marshal an effective response to fluctuating conditions; making decisions under conditions of uncertainty; communicating with conspecifics and others (honestly and deceptively); and coordinating collective behaviour to increase the chances of survival.” Without thinking or perceiving as humans would have it, an act of basic cognition is arguably a simple step-by-step process through which an organism senses a stimulus, then finds an appropriate response in its repertoire and enacts the response. However, the biological details of such basic cognition have neither been delineated for a great many species nor sufficiently generalized to stimulate further investigation. This lack of detail is due to the lack of a science dedicated to the task of elucidating the cognitive ability common to all biological organisms. That is to say, a science of cognitive biology has yet to be established. A prolegomena for such science was presented in 2007 and several authors have published their thoughts on the subject since the late 1970s. Yet as the examples in the next section suggest, there is neither consensus on the theory nor widespread application in practice.

Although the two terms are sometimes used synonymously, cognitive biology should not be confused with the biology of cognition in the sense that it is used by adherents to the Chilean School of Biology of Cognition. Also known as the Santiago School, the biology of cognition is based on the work of Francisco Varela and Humberto Maturana, who crafted the doctrine of autopoiesis. Their work began in 1970 while the first mention of cognitive biology by Brian Goodwin (discussed below) was in 1977 from a different perspective.

History

'Cognitive biology' first appeared in the literature as a paper with that title by Brian C. Goodwin in 1977. There and in several related publications Goodwin explained the advantage of cognitive biology in the context of his work on morphogenesis. He subsequently moved on to other issues of structure, form, and complexity with little further mention of cognitive biology. Without an advocate, Goodwin’s concept of cognitive biology has yet to gain widespread acceptance.

Aside from an essay regarding Goodwin’s conception by Margaret Boden in 1980, the next appearance of ‘cognitive biology’ as a phrase in the literature came in 1986 from a professor of biochemistry, Ladislav Kováč. His conception, based on natural principles grounded in bioenergetics and molecular biology, is briefly discussed below. Kováč’s continued advocacy has had a greater influence in his homeland, Slovakia, than elsewhere partly because several of his most important papers were written and published only in Slovakian.

By the 1990s, breakthroughs in molecular, cell, evolutionary, and developmental biology generated a cornucopia of data-based theory relevant to cognition. Yet aside from the theorists already mentioned, no one was addressing cognitive biology except for Kováč.

Kováč’s cognitive biology

Ladislav Kováč's “Introduction to cognitive biology” (Kováč, 1986a) lists ten ‘Principles of Cognitive Biology.’ A closely related thirty page paper was published the following year: “Overview: Bioenergetics between chemistry, genetics and physics.” (Kováč, 1987). Over the following decades, Kováč elaborated, updated, and expanded these themes in frequent publications, including "Fundamental principles of cognitive biology" (Kováč, 2000), “Life, chemistry, and cognition” (Kováč, 2006a), "Information and Knowledge in Biology: Time for Reappraisal” (Kováč, 2007) and "Bioenergetics: A key to brain and mind" (Kováč, 2008).

Academic usage

University seminar

The concept of cognitive biology is exemplified by this seminar description:

University workgroup

The University of Adelaide has established a "Cognitive Biology" workgroup using this operating concept:


Members of the group study the biological literature on simple organisms (e.g., nematode) in regard to cognitive process and look for homologues in more complex organisms (e.g., crow) already well studied. This comparative approach is expected to yield simple cognitive concepts common to all organisms. “It is hoped a theoretically well-grounded toolkit of basic cognitive concepts will facilitate the use and discussion of research carried out in different fields to increase understanding of two foundational issues: what cognition is and what cognition does in the biological context.” (Bold letters from original text.)

The group’s choice of name, as they explain on a separate webpage, might have been ‘embodied cognition’ or ‘biological cognitive science.’ But the group chose ‘cognitive biology’ for the sake of (i) emphasis and (ii) method. For the sake of emphasis, (i) “We want to keep the focus on biology because for too long cognition was considered a function that could be almost entirely divorced from its physical instantiation, to the extent that whatever could be said of cognition almost by definition had to be applicable to both organisms and machines.” (ii) The method is to “assume (if only for the sake of enquiry) that cognition is a biological function similar to other biological functions—such as respiration, nutrient circulation, waste elimination, and so on.”

The method supposes that the genesis of cognition is biological, i.e., the method is biogenic. The host of the group’s website has said elsewhere that cognitive biology requires a biogenic approach, having identified ten principles of biogenesis in an earlier work. The first four biogenic principles are quoted here to illustrate the depth at which the foundations have been set at the Adelaide school of cognitive biology:
  1. “Complex cognitive capacities have evolved from simpler forms of cognition. There is a continuous line of meaningful descent;”
  2. “Cognition directly or indirectly modulates the physico-chemical-electrical processes that constitute an organism;”
  3. “Cognition enables the establishment of reciprocal causal relations with an environment, leading to exchanges of matter and energy that are essential to the organism’s continued persistence, well-being or replication;”
  4. “Cognition relates to the (more or less) continuous assessment of system needs relative to prevailing circumstances, the potential for interaction, and whether the current interaction is working or not;”

Other universities

  • As another example, the Department für Kognitionsbiologie at the University of Vienna declares in its mission statement a strong commitment “to experimental evaluation of multiple, testable hypotheses” regarding cognition in terms of evolutionary and developmental history as well as adaptive function and mechanism, whether the mechanism is cognitive, neural, and/or hormonal. “The approach is strongly comparative: multiple species are studied, and compared within a rigorous phylogenetic framework, to understand the evolutionary history and adaptive function of cognitive mechanisms (‘cognitive phylogenetics’).” Their website offers a sample of their work: “Social Cognition and the Evolution of Language: Constructing Cognitive Phylogenies.”
  • A more restricted example can be found with the Cognitive Biology Group, Institute of Biology, Faculty of Science, Otto-von-Guericke University (OVGU) in Magdeburg, Germany. The group offers courses titled “Neurobiology of Consciousness” and “Cognitive Neurobiology.” Its website lists the papers generated from its lab work, focusing on the neural correlates of perceptual consequences and visual attention. The group’s current work is aimed at detailing a dynamic known as ‘multistable perception.’ The phenomenon, described in a sentence: “Certain visual displays are not perceived in a stable way but, from time to time and seemingly spontaneously, their appearance wavers and settles in a distinctly different form.”
  • A final example of university commitment to cognitive biology can be found at Comenius University in Bratislava, Slovakia. There in the Faculty of Natural Sciences, the Bratislava Biocenter is presented as a consortium of research teams working in biomedical sciences. Their website lists the Center for Cognitive Biology in the Department of Biochemistry at the top of the page, followed by five lab groups, each at a separate department of bioscience. The webpage for the Center for Cognitive Biology  offers a link to "Foundations of Cognitive Biology," a page that simply contains a quotation from a paper authored by Ladislav Kováč, the site’s founder. His perspective is briefly discussed below.

Cognitive biology as a category

The words ‘cognitive’ and ‘biology’ are also used together as the name of a category. The category of cognitive biology has no fixed content but, rather, the content varies with the user. If the content can only be recruited from cognitive science, then cognitive biology would seem limited to a selection of items in the main set of sciences included by the interdisciplinary concept—cognitive psychology, artificial intelligence, linguistics, philosophy, neuroscience, and cognitive anthropology. These six separate sciences were allied “to bridge the gap between brain and mind” with an interdisciplinary approach in the mid-1970s. Participating scientists were concerned only with human cognition. As it gained momentum, the growth of cognitive science in subsequent decades seemed to offer a big tent to a variety of researchers. Some, for example, considered evolutionary epistemology a fellow-traveler. Others appropriated the keyword, as for example Donald Griffin in 1978, when he advocated the establishment of cognitive ethology.

Meanwhile, breakthroughs in molecular, cell, evolutionary, and developmental biology generated a cornucopia of data-based theory relevant to cognition. Categorical assignments were problematic. For example, the decision to append cognitive to a body of biological research on neurons, e.g. the cognitive biology of neuroscience, is separate from the decision to put such body of research in a category named cognitive sciences. No less difficult a decision needs be made—between the computational and constructivist approach to cognition, and the concomitant issue of simulated v. embodied cognitive models—before appending biology to a body of cognitive research, e.g. the cognitive science of artificial life.

One solution is to consider cognitive biology only as a subset of cognitive science. For example, a major publisher’s website displays links to material in a dozen domains of major scientific endeavor. One of which is described thus: “Cognitive science is the study of how the mind works, addressing cognitive functions such as perception and action, memory and learning, reasoning and problem solving, decision-making and consciousness.” Upon its selection from the display, the Cognitive Science page offers in nearly alphabetical order these topics: Cognitive Biology, Computer Science, Economics, Linguistics, Psychology, Philosophy, and Neuroscience. Linked through that list of topics, upon its selection the Cognitive Biology page offers a selection of reviews and articles with biological content ranging from cognitive ethology through evolutionary epistemology; cognition and art; evo-devo and cognitive science; animal learning; genes and cognition; cognition and animal welfare; etc.

A different application of the cognitive biology category is manifest in the 2009 publication of papers presented at a three-day interdisciplinary workshop on “The New Cognitive Sciences” held at the Konrad Lorenz Institute for Evolution and Cognition Research in 2006. The papers were listed under four headings, each representing a different domain of requisite cognitive ability: (i) space, (ii) qualities and objects, (iii) numbers and probabilities, and (iv) social entities. The workshop papers examined topics ranging from “Animals as Natural Geometers” and “Color Generalization by Birds” through “Evolutionary Biology of Limited Attention” and “A comparative Perspective on the Origin of Numerical Thinking” as well as “Neuroethology of Attention in Primates” and ten more with less colorful titles. “[O]n the last day of the workshop the participants agreed [that] the title ‘Cognitive Biology’ sounded like a potential candidate to capture the merging of the cognitive and the life sciences that the workshop aimed at representing.” Thus the publication of Tommasi, et al. (2009), Cognitive Biology: Evolutionary and Developmental Perspectives on Mind, Brain and Behavior.
A final example of categorical use comes from an author’s introduction to his 2011 publication on the subject, Cognitive Biology: Dealing with Information from Bacteria to Minds. After discussing the differences between the cognitive and biological sciences, as well as the value of one to the other, the author concludes: “Thus, the object of this book should be considered as an attempt at building a new discipline, that of cognitive biology, which endeavors to bridge these two domains.” There follows a detailed methodology illustrated by examples in biology anchored by concepts from cybernetics (e.g., self-regulatory systems) and quantum information theory (regarding probabilistic changes of state) with an invitation "to consider system theory together with information theory as the formal tools that may ground biology and cognition as traditional mathematics grounds physics.”
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Mind–body problem

From Wikipedia, the free encyclopedia

René Descartes' illustration of mind/body dualism. Descartes believed inputs were passed on by the sensory organs to the epiphysis in the brain and from there to the immaterial spirit
 
Different approaches toward resolving the mind–body problem
 
The mind–body problem is a philosophical problem concerning the relationship between thought and consciousness in the human mind and the brain as part of the physical body. It is distinct from the question of how mind and body function chemically and physiologically since that question presupposes an interactionist account of mind-body relations. This question arises when mind and body are considered as distinct, based on the premise that the mind and the body are fundamentally different in nature.

The problem was addressed by René Descartes in the 17th century, resulting in Cartesian dualism, and by pre-Aristotelian philosophers, in Avicennian philosophy, and in earlier Asian traditions. A variety of approaches have been proposed. Most are either dualist or monist. Dualism maintains a rigid distinction between the realms of mind and matter. Monism maintains that there is only one unifying reality, substance or essence in terms of which everything can be explained.

Each of these categories contain numerous variants. The two main forms of dualism are substance dualism, which holds that the mind is formed of a distinct type of substance not governed by the laws of physics, and property dualism, which holds that mental properties involving conscious experience are fundamental properties, alongside the fundamental properties identified by a completed physics. The three main forms of monism are physicalism, which holds that the mind consists of matter organized in a particular way; idealism, which holds that only thought truly exists and matter is merely an illusion; and neutral monism, which holds that both mind and matter are aspects of a distinct essence that is itself identical to neither of them. Psychophysical parallelism is a third possible alternative regarding the relation between mind and body, between interaction (dualism) and one-sided action (monism).

Several philosophical perspectives have been developed which reject the mind–body dichotomy. The historical materialism of Karl Marx and subsequent writers, itself a form of physicalism, held that consciousness was engendered by the material contingencies of one's environment. An explicit rejection of the dichotomy is found in French structuralism, and is a position that generally characterized post-war Continental philosophy.

The absence of an empirically identifiable meeting point between the non-physical mind (if there is such a thing) and its physical extension has proven problematic to dualism, and many modern philosophers of mind maintain that the mind is not something separate from the body. These approaches have been particularly influential in the sciences, particularly in the fields of sociobiology, computer science, evolutionary psychology, and the neurosciences.

An ancient model of the mind known as the Five-Aggregate Model explains the mind as continuously changing sense impressions and mental phenomena. Considering this model, it is possible to understand that it is the constantly changing sense impressions and mental phenomena (i.e., the mind) that experiences/analyzes all external phenomena in the world as well as all internal phenomena including the body anatomy, the nervous system as well as the organ brain. This conceptualization leads to two levels of analyses: (i) analyses conducted from a third-person perspective on how the brain works, and (ii) analyzing the moment-to-moment manifestation of an individual’s mind-stream (analyses conducted from a first-person perspective). Considering the latter, the manifestation of the mind-stream is described as happening in every person all the time, even in a scientist who analyses various phenomena in the world, including analyzing and hypothesizing about the organ brain.

Mind–body interaction and mental causation

Philosophers David L. Robb and John F. Heil introduce mental causation in terms of the mind–body problem of interaction:
Mind–body interaction has a central place in our pretheoretic conception of agency. Indeed, mental causation often figures explicitly in formulations of the mind–body problem. Some philosophers insist that the very notion of psychological explanation turns on the intelligibility of mental causation. If your mind and its states, such as your beliefs and desires, were causally isolated from your bodily behavior, then what goes on in your mind could not explain what you do. If psychological explanation goes, so do the closely related notions of agency and moral responsibility. Clearly, a good deal rides on a satisfactory solution to the problem of mental causation [and] there is more than one way in which puzzles about the mind's "causal relevance" to behavior (and to the physical world more generally) can arise.

[René Descartes] set the agenda for subsequent discussions of the mind–body relation. According to Descartes, minds and bodies are distinct kinds of "substance". Bodies, he held, are spatially extended substances, incapable of feeling or thought; minds, in contrast, are unextended, thinking, feeling substances. If minds and bodies are radically different kinds of substance, however, it is not easy to see how they "could" causally interact. Princess Elizabeth of Bohemia puts it forcefully to him in a 1643 letter:
how the human soul can determine the movement of the animal spirits in the body so as to perform voluntary acts—being as it is merely a conscious substance. For the determination of movement seems always to come about from the moving body's being propelled—to depend on the kind of impulse it gets from what sets it in motion, or again, on the nature and shape of this latter thing's surface. Now the first two conditions involve contact, and the third involves that the impelling thing has extension; but you utterly exclude extension from your notion of soul, and contact seems to me incompatible with a thing's being immaterial...
Elizabeth is expressing the prevailing mechanistic view as to how causation of bodies works. Causal relations countenanced by contemporary physics can take several forms, not all of which are of the push–pull variety.
— David Robb and John Heil, "Mental Causation" in The Stanford Encyclopedia of Philosophy
Contemporary neurophilosopher Georg Northoff suggests that mental causation is compatible with classical formal and final causality.

Biologist, theoretical neuroscientist and philosopher, Walter J. Freeman, suggests that explaining mind–body interaction in terms of "circular causation" is more relevant than linear causation.

In neuroscience, much has been learned about correlations between brain activity and subjective, conscious experiences. Many suggest that neuroscience will ultimately explain consciousness: "...consciousness is a biological process that will eventually be explained in terms of molecular signaling pathways used by interacting populations of nerve cells..." However, this view has been criticized because consciousness has yet to be shown to be a process, and the "hard problem" of relating consciousness directly to brain activity remains elusive.
Cognitive science today gets increasingly interested in the embodiment of human perception, thinking, and action. Abstract information processing models are no longer accepted as satisfactory accounts of the human mind. Interest has shifted to interactions between the material human body and its surroundings and to the way in which such interactions shape the mind. Proponents of this approach have expressed the hope that it will ultimately dissolve the Cartesian divide between the immaterial mind and the material existence of human beings (Damasio, 1994; Gallagher, 2005). A topic that seems particularly promising for providing a bridge across the mind–body cleavage is the study of bodily actions, which are neither reflexive reactions to external stimuli nor indications of mental states, which have only arbitrary relationships to the motor features of the action (e.g., pressing a button for making a choice response). The shape, timing, and effects of such actions are inseparable from their meaning. One might say that they are loaded with mental content, which cannot be appreciated other than by studying their material features. Imitation, communicative gesturing, and tool use are examples of these kinds of actions.
— Georg Goldenberg, "How the Mind Moves the Body: Lessons From Apraxia" in Oxford Handbook of Human Action

Neural correlates

The neuronal correlates of consciousness constitute the smallest set of neural events and structures sufficient for a given conscious percept or explicit memory. This case involves synchronized action potentials in neocortical pyramidal neurons

The neural correlates of consciousness "are the smallest set of brain mechanisms and events sufficient for some specific conscious feeling, as elemental as the color red or as complex as the sensual, mysterious, and primeval sensation evoked when looking at [a] jungle scene..." Neuroscientists use empirical approaches to discover neural correlates of subjective phenomena.

Neurobiology and neurophilosophy

A science of consciousness must explain the exact relationship between subjective conscious mental states and brain states formed by electrochemical interactions in the body, the so-called hard problem of consciousness. Neurobiology studies the connection scientifically, as do neuropsychology and neuropsychiatry. Neurophilosophy is the interdisciplinary study of neuroscience and philosophy of mind. In this pursuit, neurophilosophers, such as Patricia Churchland, Paul Churchland, and Daniel Dennett, have focused primarily on the body rather than the mind. In this context, neuronal correlates may be viewed as causing consciousness, where consciousness can be thought of as an undefined property that depends upon this complex, adaptive, and highly interconnected biological system. However, it's unknown if discovering and characterizing neural correlates may eventually provide a theory of consciousness that can explain the first-person experience of these "systems", and determine whether other systems of equal complexity lack such features.

The massive parallelism of neural networks allows redundant populations of neurons to mediate the same or similar percepts. Nonetheless, it is assumed that every subjective state will have associated neural correlates, which can be manipulated to artificially inhibit or induce the subject's experience of that conscious state. The growing ability of neuroscientists to manipulate neurons using methods from molecular biology in combination with optical tools was achieved by the development of behavioral and organic models that are amenable to large-scale genomic analysis and manipulation. Non-human analysis such as this, in combination with imaging of the human brain, have contributed to a robust and increasingly predictive theoretical framework.
 

Arousal and content

Midline structures in the brainstem and thalamus necessary to regulate the level of brain arousal. Small, bilateral lesions in many of these nuclei cause a global loss of consciousness.

There are two common but distinct dimensions of the term consciousness, one involving arousal and states of consciousness and the other involving content of consciousness and conscious states. To be conscious of something, the brain must be in a relatively high state of arousal (sometimes called vigilance), whether awake or in REM sleep. Brain arousal level fluctuates in a circadian rhythm but these natural cycles may be influenced by lack of sleep, alcohol and other drugs, physical exertion, etc. Arousal can be measured behaviorally by the signal amplitude required to trigger a given reaction (for example, the sound level that causes a subject to turn and look toward the source). High arousal states involve conscious states that feature specific perceptual content, planning and recollection or even fantasy. Clinicians use scoring systems such as the Glasgow Coma Scale to assess the level of arousal in patients with impaired states of consciousness such as the comatose state, the persistent vegetative state, and the minimally conscious state. Here, "state" refers to different amounts of externalized, physical consciousness: ranging from a total absence in coma, persistent vegetative state and general anesthesia, to a fluctuating, minimally conscious state, such as sleep walking and epileptic seizure.

Many nuclei with distinct chemical signatures in the thalamus, midbrain and pons must function for a subject to be in a sufficient state of brain arousal to experience anything at all. These nuclei therefore belong to the enabling factors for consciousness. Conversely it is likely that the specific content of any particular conscious sensation is mediated by particular neurons in the cortex and their associated satellite structures, including the amygdala, thalamus, claustrum and the basal ganglia.

Historical background

The following is a very brief account of some contributions to the mind–body problem.

The Buddha

The Buddha (480–400 B.C.E), founder of Buddhism, described the mind and the body as depending on each other in a way that two sheaves of reeds were to stand leaning against one another and taught that the world consists of mind and matter which work together, interdependently. Buddhist teachings describe the mind as manifesting from moment to moment, one thought moment at a time as a fast flowing stream. The components that make up the mind are known as the five aggregates (i.e., material form, feelings, perception, volition, and sensory consciousness), which arise and pass away continuously. The arising and passing of these aggregates in the present moment is described as being influenced by five causal laws: biological laws, psychological laws, physical laws, volitional laws, and universal laws. The Buddhist practice of mindfulness involves attending to this constantly changing mind-stream.

Ultimately, the Buddha's philosophy is that both mind and forms are conditionally arising qualities of an ever-changing universe in which, when nirvāna is attained, all phenomenal experience ceases to exist. According to the anattā doctrine of the Buddha, the conceptual self is a mere mental construct of an individual entity and is basically an impermanent illusion, sustained by form, sensation, perception, thought and consciousness. The Buddha argued that mentally clinging to any views will result in delusion and stress, since, according to the Buddha, a real self (conceptual self, being the basis of standpoints and views) cannot be found when the mind has clarity.

Plato

Plato (429–347 B.C.E.) believed that the material world is a shadow of a higher reality that consists of concepts he called Forms. According to Plato, objects in our everyday world "participate in" these Forms, which confer identity and meaning to material objects. For example, a circle drawn in the sand would be a circle only because it participates in the concept of an ideal circle that exists somewhere in the world of Forms. He argued that, as the body is from the material world, the soul is from the world of Forms and is thus immortal. He believed the soul was temporarily united with the body and would only be separated at death, when it would return to the world of Forms. Since the soul does not exist in time and space, as the body does, it can access universal truths. For Plato, ideas (or Forms) are the true reality, and are experienced by the soul. The body is for Plato empty in that it can not access the abstract reality of the world; it can only experience shadows. This is determined by Plato's essentially rationalistic epistemology.

Aristotle

For Aristotle (384–322 BC) mind is a faculty of the soul. Regarding the soul, he said:
It is not necessary to ask whether soul and body are one, just as it is not necessary to ask whether the wax and its shape are one, nor generally whether the matter of each thing and that of which it is the matter are one. For even if one and being are spoken of in several ways, what is properly so spoken of is the actuality.
— De Anima ii 1, 412b6–9
In the end, Aristotle saw the relation between soul and body as uncomplicated, in the same way that it is uncomplicated that a cubical shape is a property of a toy building block. The soul is a property exhibited by the body, one among many. Moreover, Aristotle proposed that when the body perishes, so does the soul, just as the shape of a building block disappears with destruction of the block.

Influences of Eastern monotheistic religions

In religious philosophy of Eastern monotheism, dualism denotes a binary opposition of an idea that contains two essential parts. The first formal concept of a "mind-body" split may be found in the "divinity - secularity" dualism of the ancient Persian religion of Zoroastrianism around the mid-fifth century BC. Gnosticism is a modern name for a variety of ancient dualistic ideas inspired by Judaism popular in the first and second century AD. These ideas later seem to have been incorporated into Galen's "tripartite soul" that led into both the Christian sentiments expressed in the later Augustinian theodicy and Avicenna’s Platonism in Islamic Philosophy.

Descartes

René Descartes (1596–1650) believed that mind exerted control over the brain via the pineal gland:
My view is that this gland is the principal seat of the soul, and the place in which all our thoughts are formed.
— René Descartes, Treatise of Man
[The] mechanism of our body is so constructed that simply by this gland's being moved in any way by the soul or by any other cause, it drives the surrounding spirits towards the pores of the brain, which direct them through the nerves to the muscles; and in this way the gland makes the spirits move the limbs.
— René Descartes, Passions of the Soul
His posited relation between mind and body is called Cartesian dualism or substance dualism. He held that mind was distinct from matter, but could influence matter. How such an interaction could be exerted remains a contentious issue.

Kant

For Kant (1724–1804) beyond mind and matter there exists a world of a priori forms, which are seen as necessary preconditions for understanding. Some of these forms, space and time being examples, today seem to be pre-programmed in the brain.
...whatever it is that impinges on us from the mind-independent world does not come located in a spatial or a temporal matrix,...The mind has two pure forms of intuition built into it to allow it to... organize this 'manifold of raw intuition'.
— Andrew Brook, Kant's view of the mind and consciousness of self: Transcendental aesthetic
Kant views the mind–body interaction as taking place through forces that may be of different kinds for mind and body.

Huxley

For Huxley (1825–1895) the conscious mind was a by-product of the brain that has no influence upon the brain, a so-called epiphenomenon.
On the epiphenomenalist view, mental events play no causal role. Huxley, who held the view, compared mental events to a steam whistle that contributes nothing to the work of a locomotive.
— William Robinson, Epiphenomenalism

Whitehead

A. N. Whitehead advocated a sophisticated form of panpsychism that has been called by David Ray Griffin panexperientialism.

Popper

For Popper (1902–1994) there are three aspects of the mind–body problem: the worlds of matter, mind, and of the creations of the mind, such as mathematics. In his view, the third-world creations of the mind could be interpreted by the second-world mind and used to affect the first-world of matter. An example might be radio, an example of the interpretation of the third-world (Maxwell's electromagnetic theory) by the second-world mind to suggest modifications of the external first world.
The body–mind problem is the question of whether and how our thought processes in World 2 are bound up with brain events in World 1. ...I would argue that the first and oldest of these attempted solutions is the only one that deserves to be taken seriously [namely]: World 2 and World 1 interact, so that when someone reads a book or listens to a lecture, brain events occur that act upon the World 2 of the reader's or listener's thoughts; and conversely, when a mathematician follows a proof, his World 2 acts upon his brain and thus upon World 1. This, then, is the thesis of body–mind interaction.
— Karl Popper, Notes of a realist on the body–mind problem

Searle

For Searle (b. 1932) the mind–body problem is a false dichotomy; that is, mind is a perfectly ordinary aspect of the brain.
According to Searle then, there is no more a mind–body problem than there is a macro–micro economics problem. They are different levels of description of the same set of phenomena. [...] But Searle is careful to maintain that the mental – the domain of qualitative experience and understanding – is autonomous and has no counterpart on the microlevel; any redescription of these macroscopic features amounts to a kind of evisceration, ...
— Joshua Rust, John Searle
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