Aaron Lukaszewski

Hutson Olsen

Haliegh Roach

 

Damasio, A. R. (1999). The feeling of what happens: body and emotion in the making of

consciousness. Orlando: Harcourt.

 

Rossano, M. J. (2003). Expertise and the evolution of consciousness. Cognition, 89 (3), 207-236.

 

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Becoming Conscious

-A Look at some Evolutionary Approaches to Studying Consciousness-

                                               

Attempts to define the term ‘consciousness’ have existed since at least the time of the ancient Greeks.  Understanding the nature of consciousness, why it exists and how it is related to other phenomena has been a profound yet disturbing riddle; unsurprisingly, corroboration on the facts has eluded the scientific and philosophic communities.  Dictionary definitions are hopelessly tautological, “state of being conscious” (Oxford), or “not sleeping or comatose” (Collins).  But hope remains for clarifying ‘the big problem’, as recent neurophysiological evidence by scientists like Antonio Damasio and Richard Dawkins, in collaboration with thought experiments by philosopher Daniel Dennett, have shed new light on the nature and evolution of consciousness. 

Two extreme views on consciousness form the peripheries of the debate.  The first view, which is espoused by many scientists, is called monism.  According to monism, consciousness and the observed universe are comprised of the same elements; so all one has to do is to observe underlying neural patterns, which allow for the emergence of a ‘higher’ form of matter, conveniently called consciousness.  The competing view is labeled dualism, which espouses that consciousness and the physical world are two completely different entities.  Needless to say, both perspectives may be too extreme and limited for those who wish to bridge philosophy with the scientific method.  After all, where is free will from the monistic perspective?

In his book, The Selfish Gene, Richard Dawkins proposes a definition of consciousness that might appease the dissension of competing theorists.  He actually borrows this concept from Daniel Dennett, and writes, “Perhaps consciousness arises when the brains simulation of the world becomes so complete that it must include a model of itself (Dawkins, 59).”  If consciousness came into being as an extra energy layer and afforded the organism more space and less limitation to do humanlike things such as self-reflection, connecting abstract ideas and deliberate goal-making, then we would expect the ‘lower’ layer that was involved in the mere simulation of environmental objects to be unable to partake in these same activities.  A simulation of a simulation could be the only way that allows for self-reflection and the emergence of the autobiographical, linear self.  However, according to Dennett, this linear self is a mere illusion, because consciousness functions as a model of a parallel-processing unit that is completely absorbed in the activity of representing objects and experiences in the environment.  This idea of a liner-processing layer on top of an extremely limited parallel-processing unit finds at least partial corroboration from the work of Antonio Damasio, which will be discussed further.  Furthermore, because consciousness is such an intricate process, it makes no sense to discuss perception as an independent activity.  Perception is subsumed under consciousness by many current scientific models.

If we are to conceptualize consciousness from an evolutionary perspective, then several requisites must be stated.  Firstly, consciousness must be an inherited and useful trait that has emerged because it was proven to solve some adaptive problem of our ancestors.  Consciousness is obviously too complicated a design to be understood as just some by-product of another adaptation.  Consciousness must also, to be considered an evolved psychological mechanism, be passed along by its corresponding genes.  Another thing to keep in mind is that input from the environment should inform the organism of the adaptive problem that it must face.  Similarly, output, in the form of conscious operations, is geared towards solving the adaptive problem, and can manifest itself by either “physiological activity, information to other psychological mechanisms or manifest behavior (Buss, 51).”  Clearly consciousness must solve some sort of adaptive problem.  What problem that is and how it developed are questions that researchers like Antonio Damasio have studied extensively.    

 

An Evolutionary Theory of Consciousness and its Neural Correlates

 

            In his 1999 book The Feeling of What Happens: Body and Emotion in the Making of Consciousness, the neurologist Antonio Damasio put forth a theory of consciousness that is cradled by evolutionary theory and neurological evidence. Damasio hypothesizes that consciousness begins when brains acquire the power of telling a nonverbal story of an organism’s interaction with its environment. He views the ability of neural tissue to tell such a story to be a supreme adaptation that prevailed in evolution because it allowed the organism to “know” itself in the context of the great drama of life. In this drama, the self is always the protagonist. But just what is the experience of self and how did it evolve? This is a primary topic addressed by Damasio. The foregoing summary will attempt to convey, as simply as can be afforded, Damasio’s theory of how consciousness evolved through three sets of processes implemented in the brain: proto-self, core consciousness, and extended consciousness.

            Before delving into the theory, it will be advantageous for us to define some concepts that will recur throughout this discussion. First, Damasio draws a distinction between emotions and feelings. Typically, when we think of emotions we think of concepts like sadness, elation, jealousy, and so forth. Here, emotions are non-conscious neural representations of physiological responses to encountered or imagined stimuli. Feelings, on the other hand, happen only when the emotion becomes known (or conscious). This is a distinction that will become clearer later. Another concept that will be referred to repeatedly is that of an image. An image can be thought of as any neural pattern that generates a mental representation of the self, an object, a concept, or abstract property thereof. The concept of an image ties back in with those of emotions and feelings. Emotions are images that non-consciously signify a physiologic change in the organism, while feelings are images that represent the emotion as a known relationship between the organism and the object that caused the change.

            Damasio notes that the “life urge” (or the inexplicable desire to maintain homeostasis within the boundaries of an organism) is not a new phenomenon, but one that exists even in the single-celled organism. By way of a selectively permeable membrane, the single cell maintains its cytoplasmic (intra-cellular) environment within certain boundaries so to sustain life. As it turns out, animals and humans are not so different from the single-cell. In organisms endowed with a brain, the monitoring of the state of the body is performed by a collection of “old brain” (or sub-cortical) structures. The neural representation of the moment-to-moment state of the organism with respect to homeostasis is the foundation for what Damasio calls Proto-self.

            Proto-self is “a coherent collection of neural patterns which map, moment by moment, the state of the physical structure of the organism in its many dimensions.” Proto-self is thought to be implemented by several brain stem nuclei, the hypothalamus, the basal forebrain, and the insular cortex. Several different kinds of signals from the body inform proto-self. There are neural inputs from the musculo-skeletal system and the viscera (heart, lungs, stomach, etc.). Another major source of information comes from the internal milieu (the aqueous environment of the body as indicated by concentrations of chemicals in the bloodstream). This process of mapping is non-conscious, has no language, and has no knowledge, but it does form the representation of the body that will be the foundation for the sense of self later in evolution. Think of proto-self as a collection of images that represent the physical status of the organism for the purpose of life maintenance.

Proto-self can be affected by encounters with external stimuli via unconscious autonomic reactions, or as Damasio has defined them, emotions. The object that affects the organism is what Damasio calls the “something to be known,” which foreshadows the importance he will place on the relationship between the object and the organism in the making of consciousness. As Damasio points out, there is no shortage of knowledge about how objects are represented in the sensory cortices. Neuropsychology has investigated with some success the processing of color, shape, motion, and auditory frequency. Such sensory representations are accompanied by complex effects on the proto-self, which are emotions. (Also note that organisms with memory can be affected in the same way by simply recalling a previously encountered object.) So far we know that proto-self is the non-conscious mechanism that maps the state of the organism, which can be affected by sensory representations of objects. Now, we shall move on to describing the next processes involved in becoming conscious: core consciousness.

Core consciousness “occurs when the brain’s representation devices generate an imaged, nonverbal account of how the organism’s own state is affected by the organism’s processing of an object, and when this process enhances the image of the causative object, thus placing it saliently in a spatial and temporal context.” In the previous paragraph, we discussed how sensorimotor maps pertaining to the object cause changes in proto-self. Core consciousness happens when a change in proto-self is re-represented in a “second order” map. This second order map represents the relationship between the object and the organism. Because the changes in body states being represented in proto-self and re-represented in second order maps are related to changes in the physical status of the body (emotions), the mental images that describe the relationship are feelings—at this stage we are conscious for the first time of the relationship between the object and the organism; indeed, we can feel that one causes a change in the other. Damasio tentatively proposes that such second order maps arise transiently out of interactions among a select few brain regions: the cingulate cortex, the superior colliculi, the thalamus, and some prefrontal cortices. (Notice that all brain regions discussed so far exist in other mammals, and some in reptiles.)

Damasio views core consciousness as something that is constantly re-generated in second order maps along with the ever-changing proto-self. Core consciousness is created in pulses, each pulse triggered by each object that we interact with or recall. In other words, if there is an image of an object that exists in our perception, either processed or recalled, it is affecting proto-self in the form of an emotion, and being represented and re-represented in pulses of core consciousness. Organisms became conscious when we began to know about the relationship between the object and the organism, and when we knew that the organism was “I”. A pulse of core consciousness is the feeling of knowing yourself. Damasio presents an inner monologue to illustrate how this feeling of knowing comes to be: “if these images have the perspective of this body I now feel, then these images are in my body—they are mine……these images are mine and I can act on the object that caused them.” Think of the possible adaptive problems that are being solved with this revelation. To know the feelings that cause changes to one’s organism, and know them as favorable or unfavorable, is to have a basis for formulating tactics for interacting with the objects of the world in such a way that is advantageous for the homeostasis of the body, upon which the experience of consciousness is based. Consciousness is destined to serve the body’s homeostasis.

In Damasio’s view, a pulse of core consciousness is the basis of focused attention. When an object affects proto-self, and this relationship is generated in a pulse of core consciousness, the consequence is that the image of the causative object will be enhanced and other images will be inhibited, thus focusing the “spotlight” of attention onto the image that is presently causing a change in proto-self. It is important to note at this juncture that animals have core consciousness. Consider your dog. Your dog knows it is it. It knows you are you. It understands the causal relationship between you and it. The constantly regenerated pulses of core consciousness are what make a dog conscious, and allow it to focus attention on causative stimuli in the environment. What then is the difference between the consciousness of animals and humans? The answer is that humans have evolved past core consciousness, and the transient awareness for which it allows, to have extended consciousness, which will be explained below.

Extended consciousness is what we are inclined to think of when we consider consciousness in the human sense of the word. Indeed, extended consciousness is uniquely human. But just what is it that we have? What makes us have the capacity to know what we know? To consider hypothetical scenarios? To remember past life events and feelings? According to Damasio, “Extended Consciousness goes beyond the here and now of core consciousness, both backward and forward.” What allows for this extension beyond the here and now is memory—for the past and for the future. Each pulse of core consciousness we experience has the potential to become a memory, either implicit or explicit. The autobiographical self is a composition of the gradual buildup of memories that were at one time pulses of core consciousness. Damasio explains the development of such a system in the developmental sense: “Over evolutionary time as well as individual time, our autobiographical selves have permitted us to know about progressively more complex aspects of the organism’s place and potential range of action in the complicated universe.”

The mechanism by which we pull these memories into conscious accessibility is working memory. In working memory, one can simultaneously hold many images, and integrate new images with those recalled from the autobiographical memory store. Working memory is where “thought” would seem to happen. When an image is recalled from its dispositional form (in autobiographical memory) into working memory, it is experienced as its own pulse of core consciousness, changing proto-self in the same way as it did during the original encounter. Consider the implication of this last notion. This explains why simply recalling an encounter or particular image to mind can evoke such intense feelings—we are literally re-experiencing a pulse of core consciousness that was generated in the past and stored in autobiographical memory. In a similar way, we can pull hypothetical images of the anticipated future into working memory, which are approximations of a future event based on other similar past experiences or stored memories.

The neural basis of extended consciousness includes all of the brain regions involved in proto-self and core consciousness, as well as distributed processing systems on the cerebral cortex (the evolutionarily “newest” part of the brain). The progressively newer brain regions involved in the implementation of proto-self, core consciousness, and extended consciousness are consistent with the idea that such levels of consciousness evolved with the phylogenetic development of the brain.

Damasio views proto-self and core consciousness as processes that are essentially installed by the genome. Extended consciousness is initially programmed by genes as well, but is necessarily molded by experience to a great extent. Indeed, all the contents of memory that allow for extended consciousness are based on specific memories of prior pulses of core consciousness that are only acquired by way of experience. However, how we perceive the world as we encounter it is based on evolved psychological mechanisms and is thus inexorably influenced by our phylogenetic memories passed on to us from the Pleistocene.

This theory of consciousness is based on evolutionary theory and neurological evidence amassed from Damasio’s decades of encounters with neurological patients, so it is based on empirical support; however, going about testing such a theory will require various angles of attack. Hypotheses about the evolution of consciousness are not easily tested. The next segment of this discussion summarizes a proposition for a new technique for studying the evolution of consciousness: using evidence of expertise to draw inferences about the development of consciousness.

 

Studying Consciousness: Expertise as Evidence of the Evolution of Consciousness

           

            In a recent paper, Rossano (2003) argues that the evolution of human consciousness can be assessed using fossil evidence of skilled behavior. His rationale for this thesis rests on the validity of three basic tenets: (i) expertise requires deliberate practice (ii) deliberate practice requires consciousness (iii) evidence of expertise exists in both non-human animals and in the fossil record of hominid evolution, and these sources can be used to study the evolution of consciousness. The foregoing discussion will summarize Rossano’s basic arguments for these tenets and some of the related empirical support, and point out parallels between the present discussion and Damasio’s theory.

            Rossano defines two different types of consciousness: phenomenal consciousness and access consciousness. Phenomenal consciousness can be defined as a subjective “feeling” of a mental state (core consciousness?), while access consciousness can be defined as a mental representation that is available for use in reasoning or the rational control of action (extended consciousness?). Rossano’s paper addresses the study of access consciousness, which seems to echo Damasio’s extended consciousness as a concept. Indeed, as Rossano points out, access consciousness cannot exist without phenomenal consciousness, but phenomenal consciousness can exist on its own.

            Rossano’s first tenet (that expertise requires deliberate practice) is non-controversial. It is plain to see, as well as established in the literature, that deliberate practice is required for the acquisition of expertise. “Deliberate practice is a unique form of activity, distinguishable from both work and play, where goal-directed, concentrated effort is expended in order to hone and improve specific mental and physical skills.” One of the key features of deliberate practice is the constant evaluation of one’s current skill state against that of a more skilled model. From this feature, a second feature of deliberate practice follows, that there is a “constant focus on elevation, not maintenance, of skill.” With both of these features of deliberate practice in mind, it should not be a reach to come to the assumption that it requires a certain level of conscious, voluntary control be maintained in order to move beyond one’s present prowess to a higher skill level. Two factors that are inherent to deliberate practice are focused attention (which, remember, is allowed for by core consciousness) and conscious control (which would have to happen in working memory in extended consciousness).

            The second tenet (that deliberate practice requires consciousness) is based on the assumption provided by the first tenet, as well as the knowledge that three cognitive processes fall outside of the capabilities of unconscious processing and therefore require conscious awareness: durable and explicit information maintenance, novel combination of operations, and intentional behaviors.

            Durability and explicitness of information maintenance refers to the ability to hold information in mind for an extended period of time, because one in deliberate practice has to use the previous attempt as a guide against which to compare the next repetition. The lack of durability and explicitness of information maintenance would not then allow for deliberate practice. Rossano seems to be discussing working memory when he refers to information maintenance, which would again follow with Damasio’s notion of working memory in extended consciousness.

            Novel combinations of operations require consciousness because experts must “continually alter and adjust their behavioral and mental strategies in order to reach more proficient levels of performance.” This, again, would require one to access information stored in memory to compare current performance and strategies against those that have been attempted in the past.

            Finally, intentional behaviors require consciousness because “an expert must be ever be able to inhibit automated responses to sensory data in order to retain the flexibility necessary to react effectively to changing circumstances.” To illustrate this point, Rossano invokes the results from a cognitive priming experiment in which subjects were instructed to fill out a word stem completion with any word other than the word they were primed with just before they completed the word stem. It turned out that subjects for whom the prime had been lightly masked (and thus left somewhat conscious of the priming word) were able to inhibit the use of the priming word much better than the heavily primed group (for whom the priming word was made unconscious). This result implies that conscious awareness is required for inhibition of an automated response. Such inhibition would allow for the behavioral flexibility present in conscious organisms, rather than the automated efference copies utilized by non-conscious organisms to execute behavior.

            Rossono’s third tenet (which is really his thesis) is that evidence of expertise exists in both non-human animals and the fossil record of hominid evolution, and these sources can be used to study the evolution of consciousness. He argues that by studying fossil artifacts from hominid evolution, we can determine, via evidence of deliberate practice, to what degree the maker of the artifact was conscious. He uses the example of Acheulean tools (which are 1.5 million years old, made be Homo Erectus, and distinguishable from Oldowan tools), which Rossano says are indicative of consciousness. The crafting of an Acheulean hand axe, for instance, would have required quite a bit of time and consideration. The complexity of the multi-component design of the hand axe suggests that the hominid would have had to “hold in mind multiple perspectives of the tool as it was being created.” Thus, it can be inferred that such a tool-maker would have been holding a mental image of the axe in mind (perhaps working memory?) in order to carry out its completion. Rossano suggests that art, symbolic artifacts, musical instruments, and tools from the course of hominid evolution can be used to study consciousness in a similar way as was in the hand axe example.

Although such an approach to studying consciousness is new (as it is freshly proposed by Rossano), we believe it represents strides in evolutionary study of consciousness. Damasio’s theory of consciousness is equally as important, as it approaches the question based on what we can observe now in neurological case-studies and comparative animal studies. Rossano, on the other hand, proposes a technique that may be useful in studying consciousness by the examination of artifacts for the evidence of deliberate practice. In this way, one theory works backward (Damasio) and one forward (Rossano). In the study of such an elusive concept as consciousness, multiple approaches that allow converging evidence may in the future provide us with more and more glimpses of ourselves as we became conscious throughout human evolution.