Evan Thompson’s book Mind In Life is an illuminating followup to his earlier book, The Embodied Mind, co-written with the late Francisco Varela and Eleanor Rosch. Thompson’s first book introduced me to a uniquely framed model of cognition summarized here in Thompson’s own words:
Sensory stimulation does not cause experience in us, which in term causes our behavior…
…perceptual experience emerges from the continuous and reciprocal interactions of sensory, motor, and cognitive processing, and is thereby constituted by motor behaviors, sensory stimulation, and practical knowledge.
This sensorimotor way of being, in its full extent, comprises locomotion, perception, emotion, feeling, and a sense of agency, in other words sentience.
While Embodied Mind left me intrigued but confused, this latest presentation of ideas informing self-hood and consciousness lays out a clear and increasingly precise way of looking at the world, or more appropriately, being in the world. This way of being is the “enactive approach” introduced in The Embodied Mind, and while it is introduced as an enactive approach to cognitive science, Thompson proposes it as a method for increasing our understanding of the perception of time, emotion, empathy, evolution, and more. Most significantly, Thompson offers the enactive approach as a resource for closing the “explanatory gap,” an expression used to represent the idea that human experience has not yet been fully explained by physical processes. The enactive approach encompasses five ideas, summarized as follows:
- Living beings are autonomous agents that actively generate and maintain themselves.
- The nervous system is autonomous and dynamic. Meaning is created through its circular and reentrant operation as opposed to being created in an information-processing, computational system.
- Cognition “is the exercise of skillful know-how in situated and embodied action.”
- A cognitive being does not move about in a pre-existing world, but instead the world is a “relational domain” revealed by an organism’s autonomous agency and interaction with its environment.
- Experience “is not an epiphenomenal side issue, but central to any understanding of the mind, and needs to be investigated in a careful phenomenological manner.”
The building blocks and application of these ideas are presented in a variety of contexts and domains including complex systems theory, philosophy of mind, molecular biology, neuroscience, evolution theory, and even artificial intelligence. The concepts presented apply to many levels of systems and organization and Thompson moves quickly between them. As a result, I found myself having to continually reorient myself to the current context. Reading about and integrating these interwoven ideas has, in itself, proved to be a self-organizing activity, dynamic and reentrant, and as such, a bit hard to wrestle with intellectually. As a way to organize these concepts, I will use the ideas of the enactive approach as a framework for both building up and drilling down, and in the end, if all goes well, this essay will coherently present my impressions of Mind in Life, a book I found to be chock full of resonant and world-view shifting ways of representing the dynamics at play in this organism and her environment.
The first idea in the enactive approach is essentially the theory of autopoiesis. Chilean biologist Humberto Maturana and his student, immunologist Francisco Varela, coined the term autopoiesis to describe the process by which biological organisms self-create and sustain themselves. The theory is most simply understood using the cell as model. A cell produces its own components, including the membrane that defines where it ends and the surrounding “molecular soup” begins. A cell produces itself in an “ongoing circular process.” Thompson provides a checklist to use for determining if a system meets the minimal characteristics of autopoiesis as follows:
1. Semipermeable Boundary: Check whether the system is defined by a semipermeable boundary made up of molecular components. Does the boundary enable you to discriminate between the inside and the outside of the system in relation to its relevant components? If yes, proceed to 2.
2. Reaction Network: Check whether the components are being produced by a network of reactions that take place within the boundary. If yes, proceed to 3.
3. Interdependency: Check whether 1 and 2 are interdependent: are the boundary components being produced by the internal network of reactions, and is that network generated by conditions due to the boundary itself? If yes, the system is autopoietic.
Thompson contends that autopoiesis is a concise and unambiguous way in which to define “life”, while other, more commonsense, means would be insufficient or unclear. To illustrate this point, using the above criteria, a bacterium and amoeba are autopoietic (and so living) but a virus and mitochrondia are not. Maturana and Varela claim that “autopoiesis is necessary and sufficient to characterize the organization of living systems.” Thompson leaves open the question of whether autopoiesis is sufficient for cognition, which he defines as “behavior or conduct in relation to meaning and norms that the system itself enacts or brings forth on the basis of its autonomy.” Instead, he settles on using the thesis that living systems are both autopoietic and cognitive as the basis for exploring the “deep continuity of life and mind.” This expression summarizes an important idea contained in Mind in Life, that “organizational properties of mind are an enriched version of those fundamental to all life.” At one end of this deep continuity of life (autopoiesis) and mind (cognition) is the single celled organism. As previously mentioned, a single cell is autopoietic: it creates and maintains is parts, including its own boundaries. The most basic elements of mind are evident as well, as illustrated by what happens when it is placed in a sucrose gradient. The cell moves randomly until it happens upon the orientation that increases its exposure to sugar and subsequently swims toward the area of greatest concentration. This example is revisited often and will illuminate later concepts.
The first idea of the enactive approach states that living organisms are autonomous. Autonomy is defined in this context using systems theory which models autonomous organization as one in which constituent processes…
- recursively depend on one another for their generation and realization as a network,
- constitute the system as a unity in whatever domain they exist, and
- determine a domain of possible interactions with the environment.
As previously described, the emergence of autonomy in the biological realm is autopoiesis. The autopoietic organism, once formed, is in no way static as it must continually renew its insides and its boundaries to remain an entity. Organisms must change to go on being, hence autonomy is inexorably dynamic. As Thompson writes “…stasis is impossible. The organism must eat and excrete; otherwise it dies. Without incessant metabolic exchange with the world there can be no emancipation of dynamic selfhood from mere material persistence.” But the system is not merely dynamic, it is complex. Described in the language of the nonlinear dynamic-systems approach, the self-organizing behavior of autopoietic organisms is “neither random nor ordered and predictable; rather it is in between, exhibiting changing and unstable patterns.” As Thompson points out, this kind of complexity is found “from the molecular and organismic to the ecological and evolutionary, as well as the neural and behavioral.”
In the context of cognitive science, the enactive approach applies the elements of autonomy and dynamism to the nervous system. The second idea of the enactive approach is elaborated by Thompson here:
The second idea is that the nervous system is an autonomous dynamic system: It actively generates and maintains its own coherent and meaningful patterns of activity, according to its operation as a circular and reentrant network of interacting neurons. The nervous system does not process information in the computational sense, but creates meaning.
While Thompson alludes to the analysis contained in Mind in Life regarding various approaches to cognitive science in the previous quotation (for instance, viewing the mind as computational), more interesting to me the explanation of how meaning emerges. The phrase he uses is “meaningful patterns of activity” and, as often happens for me when questioning the bedrock of my worldview, even this basic phrase, the constituent words of which could so easily be taken for granted, needs to be carefully examined. In this case it’s somewhat amusing since it led me to look up the meaning of meaning, that is, the linguistic meaning of the word “meaning.” In my understanding, in this context, meaning refers to the value or worth of an experience to an organism. So how does this value arise? Up until now, we know only that the autopoietic organism is autonomous and dynamic and that it must be so to maintain its existence. It does this is by sensing and moving. Maturana and Varela describe this sensorimotor interplay as “living is a process of cognition,” and “living is sense-making,” respectively. Thompson returns to our single cell bacterium moving through a sucrose gradient to illustrate this most basic example of the concept of sense-making:
The cells tumble about until they hit upon an orientation that increases their exposure to sugar, at which point they swim forward, up-gradient, toward the zone of greatest sugar concentration. This behavior occurs because the bacteria are able to sense chemically the concentration of sugar in their local environment through molecular receptors in their membranes. They are able to move forward by rotating their flagella in coordination like a propeller. These bacteria are, of course, autopoietic. They also embody a dynamic sensorimotor loop: the way they move (tumbling or swimming forward) depends on what they sense, and what they sense depends on how they move.
The meaning of sucrose as food is revealed only in relation to the cell. In and of itself, the sucrose molecule has no foodness. It is in this process of sense-making, of living, that meaning and value are are revealed. As Thompson puts it, “Sense-making changes the physicochemical world into an environment of significance and valence…” This sense-making is cognition as described in ideas three and four, the summaries of which are reiterated here:
Cognition “is the exercise of skillful know-how in situated and embodied action.”
A cognitive being does not move about in a pre-existing world, but instead the world is a “relational domain” revealed by an organism’s autonomous agency and interaction with its environment.
Thompson points out that the term cognition could be said to be conflated with adaptation and notes that the distinction in this context is that “adaptation is a condition,” and “cognition is an activity.” It’s worth taking a tangential foray into evolutionary theory with Thompson before returning to the subject of cognition. When addressing the conventionally held view of organisms adapting to external environmental pressures, Thompson offers up a different perspective that more accurately reflects the process of “dynamic stabilization.” Organisms do not evolve towards an optimal fit for a given set of environmental conditions, but persist so long as they are viable. Thompson writes, “Natural selection is actually a process that emerges out of autopoiesis…” and later, “Self-organization and natural selection (dynamic stabilization) are not opposed but actually two interwoven aspects of a single process of enactive evolution.”
He spends considerable time addressing the ways in which organisms and their environment co-evolve, and despite the fact that evolutionary theory is well outside my understanding, his treatment of the subject, like his writing in general, is accessible and engaging. In his chapter on development and evolution, he challenges the metaphor of DNA is a set of intrinsically meaningful instructions, a view he refers to as “informational dualism.” A more appropriate metaphor is offered in the expression, borrowed from Varela, of “laying down a path in walking.” In this view, there is no distinction between a plan of action and its execution. Though he cites often used language of genes “coding for” a protein or phenotypic characteristic, he points out that there is not a one-to-one relationship between DNA and proteins. Enzymatic processes inside the cell control a multi-step process that can use an identical sequence of DNA to produce different proteins depending on the chemical or environmental state of the cell. It’s interesting to note that DNA is, itself, produced by the cell’s own autopoietic system.
I return now to the topic of cognition in autopoietic organisms. Thompson never assumes we have fully integrated the novel ways in which he is using familiar terms, and thankfully helps us along by periodically reinforcing them for us, as he does here: “Cognition is behavior or conduct in relation to meaning and norms that the systems itself enacts or brings forth on the basis of its autonomy.” (emphasis mine).
Figure 1. presents the relationship of autopoietic organization, cognition, and the deep continuity of life and mind. From single cell to higher order organisms, living systems are both autopoietic and cognitive. Cognition, enaction, and sense-making are descriptors for the processes by which autopoietic organisms sustain themselves through sensorimotor interaction with their surroundings.
Figure 1. Autopoiesis, cognition, and the deep continuity of life and mind
Where the first four ideas laid the groundwork for our understanding of the enactive approach, the final idea is one of application.
Experience “is not an epiphenomenal side issue, but central to any understanding of the mind, and needs to be investigated in a careful phenomenological manner.”
As conscious humans, we take ourselves as inhabiting the most extreme end of the continuity of life and mind, and Thompson proposes that our best methods for investigating the nature of consciousness is through first-person methods. Towards this end, Thompson brings in and expands upon the philosophy of phenomenology as developed by Edmund Husserl, and later, Maurice Merleau-Ponty. The motivation being that if the enactive approach is to be applied to the explanatory gap, a first-person method of skilled inquiry will need to be developed and employed, and phenomenology could form the basis for such a method. Viewed phenomenologically, there is no reality apart from that which is disclosed to us by way of the intentional activity of consciousness. The word intention, in this context, does not denote having a purpose in mind when acting, but instead is used to describe consciousness as “aiming toward” something beyond itself. It is in this context in which phenomenology contends that consciousness is intentional. Intentional experiences are described as “mental acts” which include “perceiving, remembering, imagining, empathizing, and so on.” This intentionality or aiming beyond may or may not be object-directed. For instance, perceiving is a mental act, or intention, that is object-directed while elation need not be directed toward, or about, any object. In attempting to grasp this concept of intentionality, it seems important to understand that mental acts cannot be understood independently from that which they intend, but rather the relationship between subject and object is what’s being described.
If this first level of investigation described by the phenomenological method is focused on the relationship between subject and object, the next step in its evolution, as developed by Husserl, is the inquiry into the “genesis of intentional experience in time,” termed genetic phenomenology. Returning once again to our most basic of autopoietic organisms, the cell, we have seen that it cannot continue to exist in a static state but must continually maintain its own existence. Thompson writes, “If the organism must change its matter in order to maintain its identity, then the organism must aim beyond itself in the here and now.” He later continues, “This necessity propels the organism both forward and outward. An organism must project beyond itself, opening into the temporal horizon of its own life cycle or lifeline and the spatial horizon of the outer world. In this way, autopoiesis and sense-making enact or bring forth biological time and space…” (emphasis mine).
Need propels the cell outward and forward in time. Thompson quotes Merleau-Ponty who writes, “perceptual synthesis is a temporal synthesis” to make the point that one must take up the analysis of time-consciousness as it relates to experience of intentional objects. Thompson devotes an entire chapter of Mind in Life to relating the enactive approach to the relationship between time and experience, and, in the process, introduces neurophenomenology, a scientific methodology that brings the first-person methods of phenomenology to the study of consciousness in the context of experimental psychology and cognitive science. An interesting hypothesis is presented, based on experimental studies conducted by Varela and others, that perceived time is not based on any ticking clock, either internal or external, but instead arises from neural coherence. Also called phase synchrony, neural coherence refers to synaptic firing patterns that are synchronized across disparate populations of neurons. Further, Varela proposed that the perceived present moment, or “now” has a measurable and variable duration defined by transient patterns of synchronous neural firing. In other words, “now” is actually a brief block of time.
The analysis of the first-person experience of the present moment logically flows into the study of consciousness itself. In contrast to theories that postulate representative neural states that correlate with conscious experience (NCC or neural correlates of consciousness), Thompson writes that neurophenomenological studies show that “ongoing patterns of cortical synchronization and desynchronization correlate with fluctuations of conscious perception.” Put another way, consciousness is not a function located in some region of the brain but instead, it emerges out of changing patterns of the firing of neurons widely distributed throughout the brain. He quotes J.A.S. Kelso who writes, “Mind itself is a spatiotemporal pattern that molds the metastable dynamic patterns of the brain.”
Thompson elaborates on the ways in which neurophenomenology is developing into an experimental methodology in which first-person reports of subjective experience are correlated with brain activity. He describes neurophenomenology as requiring three nonreducable components of analysis: phenomenological, biological, and dynamic. He points out that the inclusion phenomenology reveals the elements of “selfhood, purposiveness, normativity, subjectivity, intentionality, temporality, and so on– that would otherwise remain invisible to science. Put another way, phenomenology offers a way of seeing the inner life of biological systems.”
Thompson expands the subject of time-consciousness, relating it to emotion and in doing so, illuminates the strong connection between the affective valence of experience and actions alluded to in the earlier cell example. The cell’s movement through the surrounding environment of a sucrose gradient can be viewed as being guided by the attractive/repulsive valence of experience. Returning to the groundwork laid by Husserl, Thompson introduces his three intentional aspects of time-consciousness: primal impression (each “now phase”), retention (the just passed now), and protention (the now about to occur). Thompson cites Husserl’s example of listening to a melody to illustrate the interdependence of these aspects of time-consciousness:
For each now-phase of the melody, each currently sounding note, there is a corresponding primal impression directed exclusively toward it. (There are also, of course, primal impressions of the now-phases prior to and after the completion of the melody.) Primal impression involves no reference to either the past or future, and so by itself is insufficient for the perception of the melody (and for the experience of any temporal object, no matter how brief its duration). Primal impression must be accompanied by retention and protention.
One might be tempted to think that protention is unnecessary to the experience of melody, but it is noted that if the music were to suddenly stop, it would be startling. Our consciousness of the coming now-phase “always involves an open and forward looking horizon.” It is evident that retention and protention are qualitatively different as one is filled with a just-passed experience, and the other has contents yet unknown. This all gets quite confusing when Thompson points out the recursive nature of the flow. Retention is not only retention of what just occurred but also retention of the protention of the previous now. It is by virtue of this fact that Thompson is able to introduce motivation and emotional valence into the perception of every moment. He writes, “Retention always includes retention of protention and the way protention is fulfilled or unfulfilled…” Instead of being linked together, the present now’s retention pointing to the previous now, etc… as in the top half of Figure 2., now’s are nested recursively as shown in the bottom half of Figure 2.
If I were to apply Merleau-Ponty’s three-phase model of time-conscious to the cell in sucrose example, I imagine it would proceed something like this: the cell senses the presence of sucrose in the current “now-phase” and protends/anticipates its continuation in the next moment. If it encounters less sucrose it will be received as negatively valanced and alter course. If it encounters more sucrose it will be received positively and continue forward. The past, present, and anticipated nows are all necessary to effectively guide the cell.
Applying the enactive approach to emotion and cognition, neural processes can be viewed as having cyclic components of action-perception and sensation-movement. Thompson writes that “Emotion is embodied in the closed dynamics of the sensorimotor loop, orchestrated endogenously by processes up and down the neuraxis, especially the limbic system.” A “neurodynamical model” of emotion and cognition, developed by Walter Freeman, is presented by Thompson to address the question of how unconscious and conscious emotive behavior emerge out of neural activity. I can’t begin to make sense of this model which includes feedback and feedforward sensory, proprioceptive, motor, and time-space loops. Nonetheless, I am fascinated by Thompson’s observations of how Freeman relates his model to consciousness. Freeman proposes that global, coherent patterns of neuronal activity correlate to awareness, and as Thompson describes it, that “consciousness consists of a sequence of such states.” He continues to describe the implications of Freeman’s model, writing that, “Awareness, according to this model, far from being epiphenomenal, plays an important causal role…” regulating dynamic activity. He summarizes that, “…according to the enactive approach, sensorimotor processes modulate but do not determine, an ongoing endogenous activity, which in turn infuses sensorimotor activity with emotional meaning and value for the organism.”
Thompson proposes first-person methods, like those offered by phenomenology, could be developed to hone one’s attentional skills and provide a rich source of data to compliment conventional science’s third-person observations. The positive feedback loop created in the process of cultivating awareness opens up intriguing possibilities in the study of consciousness.
When viewing one’s self as an autopoietic organism, quotes like this one from J.A.S Kelso are intriguing. Referring to collective self-organization and dynamic systems he writes, “the system organizes itself, but there is no ‘self’, no agent inside the system doing the organizing.” It’s no surprise that, in his earlier writings with Varela, Thompson delves into buddhist mindfulness practices. The absence of an agent in autopoietic organisms, ourselves included, is consistent with experiences of “no-self” that emerge from countless contemplative traditions that hone attentional skills. Though commonly viewed as two sides of an unbridgeable gap, the inner and outer worlds of subject and object are integrated in the enactive approach that takes us from the most basic forms of biological life to the most vexing and long-standing questions of human existence: questions of consciousness, identity, and even free will.