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Embodiment and consciousnessMind in Life Evan Thompson Harvard University Press Keywords: cognitive science, embodied dynamism, consciousness INTRODUCTION: Embodied dynamism or the enactive approach developed out of the apparent short comings of late 20th century cognitive science. The central idea is that mind is embedded in the body, the motor actions and the external environment. Autonomy is seen as a key feature of living organisms, and the world of the cognitive being emerged from the interaction of body, brain and environment, with consciousness linked to this and seen as a central feature, rather than a by-product as in more traditional cognitive science. This book calls for an expanded notion of the physical to account for the subjective element within the physical world. However, although the approach may appear more flexible and thoughtful than more traditional cognitive science, in the end there remains an explanatory gap as to why the inclusion of the body and the environment gives rise to a consciousness that cannot be found in the brain as described by neuroscience. The term cognitive science arose in the late 20th century, as research that embraced neuroscience, psychology, linguistics, computer science and artificial intelligence. The goal was to make explicit the mechanisms of cognition. Cognitive science began as part of a revolution against behaviourism, which had dominated thinking in these areas through much of the 20th century. Behaviourism thought in terms of sensory input and prior conditioning. More recently, cognitive science has been criticised for neglecting emotion and subjective experience. Three approaches emerged in cognitive science, the mind as computer, the mind as neural network (connectionism) and embodied dynamism (enactive approach). Classical cognitive science was based on the computer model of the brain, which required internal processing. Both brain and computer are viewed as symbol-manipulating systems. Non-symbolic sensory inputs to the brain are transduced into symbolic representations. These symbols are manipulated in a formal way to produce the solution to a particular problem. The focus is on abstract problem solving, the content of symbolic representations and the nature of the algorithm for solving the manipulations. This form of cognitive science was linked to functionalism, which claimed that only the abstract system mattered for generating mind matter, and it was irrelevant whether it was embodied in a brain, a silicon computer or some other system. Cognitive science is seen as inheriting a taboo on discussing consciousness from behaviourism. The inner symbol language of the cognitive science brain was viewed as non-conscious. Consciousness was seen as merely having access to the results of non-conscious processing. This processing is in a kind of CPU separate from consciousness, emotion, perception and motor action. Cognitivism made no attempt to provide an account of subjective experience. Connectionism provided a limited critique of cognitive science. It focused on the limitation of the symbol system in terms of non-conscious processing. Connectionist models of cognitive processing take the form of artificial neural networks. There was an emphasis on pattern recognition, rather than deductive reasoning. Embodied dynamism or the enactive approach that emerged in the 1990s included the implications of the mind being embedded in the body, motor actions and emotions and the external environment. It is still accepted in this approach that most processing is unconscious. However, the followers of the embodied dynamic approach had, in some cases, a greater wish to form a link with subjectivity. Varela, Thompson and Rosch developed this approach in the early 90s. They emphasised that living organisms were autonomous. Nervous systems were also seen as autonomous, because they maintained their own levels of activity. Cognition was viewed as emerging from patterns of perception and action. The world of a cognitive being is argued to arise from interaction with the environment, rather than being a pre-specified activity. Consciousness was something central, rather than an unimportant by-product. Consciousness and the autonomy and intentionality of living entities were seen as being linked. According to the enactive approach, mind emerges from the interconnected brain, body and environment. The autonomy of living entities is emphasised, as opposed to behaviour being determined by input/processing/output. Phenomenology as derived from the philosopher, Husserl, emphasised that we can adopt differing first-person stances towards the world. It is possible to step back, and examine the actual experiences that we are having. The concept of reality is seen as involving the activity of consciousness. The self is viewed as formed by its individual history, the body, the environment, and as being something concrete with convictions, interests etc., as a result of accumulated experience. In recent years, there has been interest in a dynamical approach to cognition and emotion. Biological processes are often non-linear. This leads to complexity or chaos that is neither random nor predictably ordered. This presents a very different picture from the idea of the brain as a digital computer. Also, in contrast to computer models, dynamical systems are seen as evolving in real time. The autonomy that is stressed to be an important feature of living entities is defined as the capacity to manage a flow of energy through the organism, so as to manage its own internal processes. In the nervous system sensory activity and movement are thought of as coupled in a continuous circular fashion. Meaning is seen as the result of the brain system coupling with the environment. Something acquires meaning for an organism to the extent that it relates to maintaining the organism's integrity. The system needs a semi-permeable boundary, such as a membrane and an energy currency, such adenosine triphosphate (ATP), which transfers energy from the breaking of chemical bonds to energy-absorbing reactions within the cell. A cell stands out as a unit that has an external boundary, and can regulate its interactions with the environment. Cognition, emotion and action require the integration of widely distributed brain regions. An important question for modern neuroscience is to determine the method of this integration. Some theorists see instability or metastability as important, in order to prevent the system being trapped in a single state. In the theory of autopoiesis formulated in the 1970s, Maturan and Varela focus on the living cell. A cell is a thermodynamically open system continually exchanging matter and energy with the environment. The cell produces its own components, which in turn regenerates the cell. There is a self-perpetuating loop of reactions. This circular process is known as autopoiesis. The cell membrane serves as a barrier to diffusion between the cell and the environment, but permits the exchange of specific matter and energy. The cell is sustained by a network of chemical transformations that would be drowned out without the protection of the membrane. The membrane itself is also produced and maintained by the chemical network that it protects. The author discusses the relationship between autopoiesis and cognition. An organism has to aim beyond itself, and thus to have a type of self, in order to exchange matter and energy with the environment. The self emerges along with a domain of interaction with the environment. This is seen as being linked to subjective consciousness. Autonomy is the basis of agency and meaning. Intentionality is taken as being a form of self-organisation. The organism is viewed as an integrated whole rather than something that is atomised, and its development is seen as interactive with the environment. Animal life is viewed as distinct from plants and fungi, in requiring sensorimotor activity, in order to obtain nourishment. Sensorimotor activity involves movement, perception and finally emotions. Feeling the presence of one's own body is seen as the beginning of consciousness, but also implies a feeling for the self and the environment. It is claimed that the separation of life and consciousness in neuroscience has made it impossible to understand consciousness. Physical accounts have tended to characterise the human system from the outside, while consciousness is described from the inside, thus leaving an explanatory gap. If mental processes are bodily processes, then there is something it is like to have bodily processes. What is required is an expanded notion of the physical to allow for the subjective aspect of the physical. This in particular needs to take account of the autonomous nature of organisms and their lack of thermodynamic equilibrium. In physics appearances can be reduced to underlying causes that exclude the subjective experience, but with consciousness, the subjective appearance is what constitutes consciousness. The author argues that the human mind is embodied in both the body and the environment around it. Mental life involves three over lapping types of activity, self-regulation, sensorimotor coupling with the environment and subjective activity. The subjective part is cognition, plus the emotionally charged interaction with the self and the surrounding environment. The understanding of consciousness is here linked not to intrinsic neural activity by itself, but interlinked with the body and the environment. Things are perceived in relation to our moving bodies. The body manifests itself in perceptual experience and as the self of motor activity. The body is experienced as both subject and object. Bodily consciousness is seen as the convergence of perception and action. The subjective character of experience includes both experience of the external environment and of the body, and also the mental experience of remembering, imagining etc. Emotion is seen as a whole-brain or even a whole-organism event recruiting and retaining the activity of many brain regions. Emotion involves the brain stem, limbic areas, cortex and visceral and motor areas, nervous, immune and endocrine systems. Emotion is not a reflex, but can be directed towards some future state. Emotion is considered to be essential to all intentional behaviour. There is a large overlap between the cognitive and emotional neural systems. The author refers to Husserl's view of the present moment, which is not seen as an instantaneous now, but as something having temporal width. It is viewed as a temporal expanse containing past and future phases, a bow and a stern, a forward and a rearward looking part. Husserl viewed the process as first impression, then holding onto that impression, and a final phase that is forward-looking towards the immediate future. Cognition requires the coordination of many separated brain regions, and consciousness is widely thought to be associated with widespread neural activity, rather than any specific brain area. Consciousness is now often associated with transient synchronous activity in neuron assemblies. The timescale of this activity is suggested to be in the range of 250-500 ms. Specific changes in synchrony are seen to occur in relation to, arousal attention, perception or the operation of working memory. Gamma frequencies are particularly associated with this process, and have been shown to play a role in perception and attention. A neural assembly requires a relaxation time, a period in which it arises, stabilises, and then switches to a new neuron assembly. This relaxation time is seen as comprising a window or temporal frame, within which everything is regarded as the present moment. A study of (Rodriguez, 1999) is as supporting this concept. |
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