Table of Contents
1. The Evolution of the Human Brain
2. An Overview of Modern Neuroscience
3. The Neuroscience of Behaviour
4. The Neuroscience of Consciousness
5. The Neuroscience of Our Inner Voice
6. The Neuroscience of Free Will
7. The Principle of Emergence
8. Social Interaction and the Emergence of Freedom and Responsibility
9. Determinism Strikes Back
10. Rescuing Accountability from the Determinist Trap
The question of whether or not we truly have a free will has vexed humans for ages. On the one hand, it certainly feels as though we do: when it comes to the decisions that we make and the behaviour that we engage in, we experience the world as though it is ‘I’, the conscious self, who is responsible for these choices. Indeed, even though we may acknowledge that there are certain physical, biological, and social forces that influence our decisions and actions, we nonetheless feel as though ‘we’ are somehow separate from these impersonal forces, and that rather than being at their whim, it is ‘we’ who are the final arbiters in making the choices that we do. The experience of being able to choose as we wish is what we call free will, and it has traditionally been thought that it is an essential, if not the essential feature of what it means to be human.
However, as the study of the brain has progressed over the past century (and particularly in the past 40 years), the evidence seems to point more and more towards the idea that our sense of freedom, and our being in control of our choices, is a mere illusion, and that our thoughts and actions are in fact as determined as the physical world around us. The idea of a determined self not only challenges our traditional understanding of ourselves, but has practical repercussions in terms of our understanding of issues such as agency and responsibility, and forces us to ask whether we can legitimately hold people accountable for their actions. Indeed, if people truly are determined to behave as they do, then they could not reasonably be considered responsible for their behaviour, and hence it would seem to be unjust to punish them for their actions, thus throwing our entire judicial system into question. These issues have already begun to surface in our court systems, and have in fact had an impact on certain court decisions to exercise leniency on convicted offenders where this would not have occurred previously (p. 190-4).
According to neuroscientist Michael Gazzaniga, however, this whole line of thinking is both dangerous and misguided. This proves to be the case because, for him, the findings coming out of brain science do not in fact imply a determined self. Indeed, Gazzaniga claims that the idea of a determined self is based on a misinterpretation of the relationship between the mind and the brain, and that the proper interpretation of this relationship reveals that there is room for both responsibility and accountability. To elaborate, the idea of a determined self is based on the notion that the mind and its mental states are no more than a lifeless by-product of neurochemical activity in the brain. Since this neurochemical activity operates according to fixed physical laws, it is argued that the mind itself is a by-product of these fixed physical laws, and hence could not be free.
Gazzaniga agrees that the mind and its mental states emerge out of neurochemical activity in the brain. For him, though, the mind is not a lifeless by-product of this neurochemical activity. Rather, he maintains that once the mind emerges from underlying processes it takes on a life of its own, to the point where it becomes an independent force, capable of having a causal effect on the same neurochemical activity out of which it emerged, thus allowing it to influence future brain and mind states. Though this may sound somewhat suspicious, there is in fact plenty of precedent for this type of phenomenon elsewhere in nature. Indeed, it is based on the principle of emergence, which is coming to be appreciated as a major force in explaining how all sorts of complex systems emerge out of more basic building blocks. In this new light, the mind is not a determined entity, but is instead a free agent that is responsible for its actions, and hence capable of being legitimately held accountable for them.
This is the argument that Gazzaniga makes in his new book ‘Who’s in Charge? Free Will and the Science of the Brain’. In order to get this argument off the ground though, Gazzaniga takes us on a tour of the brain based on the latest findings from neuroscience (including what neuroscience is revealing about the question of free will), as well as a tour of the evolution of the brain, and it is here where we shall begin.
*To check out this book at Amazon.com, or purchase it, please click here: Who’s in Charge?: Free Will and the Science of the Brain. The book is also available as an audio file from Audible.com here: Audio Book
What follows is a full executive summary of Who’s in Charge?: Free Will and the Science of the Brain by Michael Gazzaniga.
1. The Evolution of the Human Brain
We may acknowledge that human beings are just as much a part of the natural world (and just as much the product of evolution) as any other living creature from cockroaches to chimpanzees. However, a quick comparison of how different creatures live will reveal a big difference between us and any other species we can think of. To begin with, while our closest living relative, the chimpanzee, struggles with termite sticks and leaf sponges, human beings have designed and fabricated a mind-boggling array of technological devices from sliced bread to rocket ships. To take just one quirky example of how crazy-amazing (author’s words) our technological acumen is, “a monkey with a neural implant in North Carolina can be hooked up to the Internet, and, when stimulated, the firing of his neurons can control the movements of a robot in Japan. Not only that, the nerve impulse travels to Japan faster than it can travel to that monkey’s own leg!” (p. 8).
Additionally, while our chimp cousins sit on the brink of extinction, we have succeeded in spreading to every corner of the world, and manage to stay in touch and cooperate with one another unlike any other species. Think about your dinner consisting of a local salad, Chilean pears, Italian gorgonzola, New Zealand lamb chops, Idahoan potatoes and a French red wine. The number of innovations and amount of cooperation that was needed in order to bring this meal together is staggering: “from the person who first thought about growing his own food, and the one who thought the old grape juice was a bit interesting, to Leonardo, who first drew a flying machine, to the person who took the first bite of that mouldy-looking cheese and thought they had a winner, to the many scientists, engineers, software designers, farmers, ranchers, vintners, transporters, retail dealers and cooks who contributed. Nowhere in the animal kingdom does such creativity or cooperation between unrelated individuals exist” (p. 9).
Finally, human beings are curious unlike any other species; and not just about nature and what lies beyond the stars, but about ourselves and our brains and what make us tick. In the author’s own words “man has always been intrigued with the nature of the mind, self, and the human condition… That is not what your dog is thinking about on the couch” (p. 9). This curiosity and desire to understand ourselves has driven a long-standing tradition of trying to identify precisely what it is about humans that separates us from other creatures. While numerous abilities and faculties have been proposed (from consciousness to language and everything in between), sooner or later someone comes along who points out that the ability or faculty in question also exists in other animals, albeit in a more rudimentary or less complex form. Nevertheless, while the differences in faculties and abilities between us and other animals may only be quantitative and not qualitative in nature, the quantitative differences turn out to be so great as to have led to what are, for all intents and purposes, true qualitative differences in our experience of the world and our way of life (as touched upon above).
Whatever the proposed differences between us and other animals have been, virtually all of them stem out of our brains, and for a long time it was thought that our big brains were the first feature to have evolved in our ancestors that separated us from our closest evolutionary relatives. However, more recent fossil finds have revealed that it was not our brains that evolved first but our legs; that is, we became bipedal before we became big brained. Evidence for this has come from numerous fossil finds, such as the discovery of Lucy, a 4 million year old hominid with a small brain but a pelvic structure set for upright walking, and another fossil from 4.4 million years ago that suggests that our bidpedalism began as early as this date (p. 24). Why bipedalism? It appears that walking on two legs allowed our ancestors to branch out from the rainforests of Eastern Africa onto the adjoining plains, as bipedalism allowed them to traverse the plains much more efficiently.
While bipedalism allowed us to spread out onto the plains, we were now living in an environment that demanded further modifications. For one, we were now exposed to the big cats of the African plains, against which we were not well adapted to defend ourselves. The solution, it appears, was to stick together in larger and larger groups—the better to defend ourselves against attacks; which solution also had the added benefit of providing us with more and better opportunities for cooperative scavenging and hunting (p. 26). Group living offered its own challenges, however, as competition between group members for resources such as food and mates became even fiercer. Meanwhile, the potential benefits of cooperation demanded sophisticated mental capacities and attitudes not necessarily fully developed by our ancestors living in the rain forests. In order to negotiate the new challenges (and exploit the possible benefits) of group living, a bigger, more sophisticated brain was needed, and so selection pressure favoured just that, and our brains began to grow.
A bigger more complex brain was also beneficial in coming up with new uses for our recently freed-up hands, and so was also favourable in this regard (p. 26). The production of rudimentary tools soon followed, which allowed for more successful scavenging and hunting, and the increased access to meat afforded by these developments provided an important source of energy to allow for ever more brain growth (the brain uses up an enormous amount of energy—up to 20% of the body’s total for an organ representing only 2-3% of body weight—and requires a large number of calories to become viable, which additional meat would have provided).
In connection with this development, the academic Owen Lovejoy has hypothesized that a major new use that males put their hands to was brining meat back to camp with which to exchange with females for sexual favours (p. 26). This development completely changed the group dynamic between males and females, and led us to become a more monogamous, less aggressive species (I have already addressed this fascinating topic extensively in a previous article and so will not go into further detail here. If you wish to look into this discussion it can be found in the blog post entitled ‘A Synopsis of Steven Pinker’s ‘The Better Angels of Our Nature: Why Violence Has Declined’ in the chapter on Dominance [Part I, Chapter 2]).
With regards to what drove the enlarging hominid brain in the course of evolution, then, it appears to have come down to two factors in particular: “a diet that provided the added calories needed to feed the metabolically expensive bigger brain, and the social challenges originating from living in those larger groups needed for protection” (p. 27).
2. An Overview of Modern Neuroscience
For much of the 20th century it was thought that the brain is nothing but a general problem-solving device, and that the new and increased mental functionality in humans was caused by an increase in the size and hence the processing power of our brains alone. In other words, it was thought that the brain has a single function (solving problems), and that this function depended on the amount of brain matter around to perform it. Hence if you took an existing brain and cut away half you would be left with the same qualitative functionality, only reduced by 50%. Alternatively, if you doubled the size of the brain you would be left with twice the ability to solve problems. In the lingo of the day, the brain was considered to be ‘equipotential’, because it was thought to be the same stuff through and through, and hence each part had equal potential in terms of functionality as any other, and no specialization was to be found (p. 11).
Together with the ‘equipotential’ understanding of the brain was the theory that the brain is a tabula rasa. That is, it was thought that the brain came into the world as a blank slate, free from pre-existing dispositions or inclinations, and that it was waiting to be shaped and oriented by whatever environmental input it happened to be exposed to. This theory is known as behaviourism—one of the most influential originators and proponents of which was the psychologist John B. Watson, who in 1930 famously said “give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I’ll guarantee to take any one at random and train him to become any type of specialist I might select—doctor, lawyer, artist, merchant-chief and, yes, even beggar man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors” (p. 12).
Discoveries in psychology and neuroscience over the past 40 years, however, have thrown both equipotentiality and behaviourism into disrepute. With regards to brain function, it is now understood that different parts of the brain are responsible for different specialized functions. The new model of the brain is known as brain modularity, on account of the fact that the brain is divided into separate modules of functionality. Additionally, it is now thought that the novel and increased functionality in the human brain is the result not only of increased brain size, but a reorganization of its structure that has allowed for added specializations unique to our species (p. 27).
In connection with this, most of us are familiar with the system of describing people as either right brained or left brained. Under this classification system so called left brained people are considered to be more logical and better with language, while right brained people are thought to be better with spatial relationships, and more artistic in nature. This classification system is overly simplistic and even somewhat misleading; however, it is based on the scientific finding that certain spatial capacities are localized in the right hemisphere of the brain, while language function is (normally) localized in the left hemisphere. In fact, the capacity for language is divided into two separate areas (both most often found in the left hemisphere), with one area mostly in charge of language comprehension (called Wernicke’s area), and another area mostly responsible for language production (called Broca’s area). As you may have guessed, both of these areas are markedly different in structure compared with other species—including chimpanzees (who do show some rudimentary ability to attain language)—thus accounting for the wide discrepancy in communication ability between ourselves and other species (p. 35).
In addition to spatial and linguistic abilities, there are numerous other mental functions that are located in specific parts of the brain. Included here are centers for vision, auditory function, sensation, motor control, short and long term memory, complex planning, causal inference and impulse inhibition (to name but a few). Even basic emotions such as fear and anger have been shown to emanate from specific areas in the brain.
How do we know all of this? The evidence for brain modularity comes from a number of different avenues. To start with, it has been discovered that damage to different parts of the brain results in the loss of different mental functions. Second, using electricity to interfere with different parts of the brain has been shown to disable different mental functions depending on which areas are targeted. Conversely, electrical stimulation of different parts of the brain has been shown to trigger different functional responses. And finally, studies using functional magnetic resonance imaging (FMRI) have shown that different areas of the brain are activated depending on what kind of mental task the subject is asked to perform (p. 33).
Evidence from all of these areas has helped to demonstrate that brain function is in fact specialized to a remarkable degree. For instance, it has been shown that a particular area of the brain is responsible for recognizing only human faces, while still another area is responsible for recognizing only fruit, while a third is responsible for recognizing only animals (p. 50). In fact, it has been shown that there may even be a specific area of the brain dedicated to recognizing only predatory animals that have figure into our evolutionary past, such as big cats and snakes (p. 50). Damage or deficits to any one of the specialized locations in the brain can lead to some very peculiar neurological disorders. (For an excellent documentary on this topic I highly recommend the following link. It features segments on akinetopsia (inability to perceive motion), prosopagnosia (inability to recognize faces), visual agnosia (the inability to recognize objects) and visual neglect (inability to process one of the visual fields). The full documentary is approximately 50 minutes long). http://documentarystorm.com/brain-story/3/
3. The Neuroscience of Behaviour
Up to this point it has been argued that our specific mental faculties and capacities are generated out of the particular wiring of our brains, which wiring was itself laid down over the course of evolution, and in such a way that the different faculties and capacities are located in different parts of our brains. As it turns out, however, our brain wiring not only informs how we process and experience the world, but also shapes our behaviour. The brain does this by way of equipping us with certain dispositions, proclivities and understandings. In other words, we are not blank slates when we enter the world, but are pre-prepared with certain orientations that inform our behaviour. Our behavioural dispositions and proclivities are perhaps best seen in our social orientation towards the world.
As Gazzaniga points out, babies come hard-wired with certain behavioural dispositions that prepare them for the social life that has been a legacy of our species for millions of years. I will mention just a few here. For one, babies come pre-wired to imitate their care-givers, thereby allowing them to form an immediate social bond from the earliest possible age (p. 143). The neurochemistry behind imitation is based on a peculiar brain cell called a mirror neuron. Mirror neurons exist as a system of brain cells that allow an organism to neurochemically mimic the actions, and even the emotions of another organism—thus allowing them to understand (and recreate) how that other organism behaves and feels (p. 161). Though mirror neurons are not exclusive to human beings (they were in fact discovered first in macaque monkeys), our mirror neuron systems have been shown to be much more extensive and complex than in any other species (p. 160). The mimicking behaviour that begins in our infancy does not end there. Indeed it has been shown that we continue to unconsciously mimic the expressions of our social interlocutors throughout the lifespan (at least those whom we like) (p. 163). As in the case of infants and their caregivers, it is thought that our unconscious mimicking of others helps us establish a social bond with those around us. This prosocial behaviour, the author explains, “may have [had] adaptive value by acting as social glue that [held] the group together, fostering safety in numbers” (P. 163).
Behavioural dispositions go well beyond just unconscious gestures. For example, infants as young as 14 months have been shown to help others altruistically without encouragement or praise; for instance, by returning an object to someone who has dropped it (p. 145) (footage of these experiments is available here [5 mins.]): http://www.youtube.com/watch?v=Z-eU5xZW7cU As Gazzaniga points out, this requires “not only understanding that others have goals and what they are, but also altruistic behavior to non-kin, an evolutionarily rare behaviour that could have foundations in our chimp relatives…” (p. 145) (footage of chimp altruism is also shown in the footage above. However, evidence that chimp altruism is not as sophisticated as our own is available here [4 mins.]) http://www.youtube.com/watch?feature=endscreen&NR=1&v=mL8OaCW1X5c In connection with our natural proclivity for altruistic behavior is our innate sense of morality (and our sense of fairness and justice in particular), which informs not only our social views, but how we behave around others (p. 208-9). This sense of fairness will be discussed further in the section on responsibility and accountability below, and therefore, I will not discuss it in detail now.
Interestingly, our inclinations towards altruistic and cooperative behaviour (which go well beyond those discussed here), are countered by other inclinations towards competition and violence. This dual aspect of our nature appears to be the result of the peculiar set of circumstances of group living, which requires not only cooperation but competition over scarce resources (p. 148-9). (For a full discussion of this topic, see the blog post entitled ‘A Synopsis of Steven Pinker’s ‘The Better Angels of Our Nature: Why violence Has Declined’).
The advantage of being equipped with innate behavioural proclivities is that these behaviours do not have to be learned—a process that takes both time and energy, and which runs the risk of not occurring at all (p. 152). Of course, it is not being suggested here that we are driven entirely by innate behavioural inclinations. Indeed, all mammals have the capacity to modify their behaviour based on what they learn from their environment. And in human beings this behavioural plasticity is taken to a level seen nowhere else in the animal kingdom. Paradoxically, behavioural plasticity is itself the result of biological evolution. Indeed, it evolved to act as a counter-balance against behavioural proclivities, which (despite being adaptive in most circumstances) can become detrimental in certain environments (p. 153). In other words, behavioural plasticity evolved because it has the advantage of allowing an organism to adapt quickly to a changing environment, which behavioural penchants lack (p. 152). Nevertheless, since certain behaviours remain adaptive in most environments, it does not pay to replace them entirely with having to learn everything anew, so a balance is struck between the two forces (p. 152).
4. The Neuroscience of Consciousness
So here is the model we are left with: we are equipped with a brain that has several specialized faculties and capacities, many of which are isolated in different parts of the brain; and we are also equipped with certain innate behavioural inclinations (some of which are completely unconscious, and some of which are not) that can, in some cases, be partially or wholly overridden by input and learning from the environment. Where then, in this whole scenario is the ‘I’; where is that consciousness that seems to unite the whole picture together and direct the show?
This is where things get a bit a quirky. As we have seen, language is constructed primarily at a particular module in the brain (most often located in the left hemisphere), and therefore, we may think that this would be the best place to start looking for the seat of consciousness. Indeed, some scientists have posited that consciousness is located in the language centre (p. 63). According to Gazzaniga, however, the evidence reveals that consciousness simply could not arise out of one particular location in the brain. Instead, Gazzaniga maintains that consciousness is spread out over numerous parts of the brain, and that it occurs at the site of each of several independent modules. In the author’s own words “phenomenal consciousness, that feeling you get about being conscious of some perception, is generated by local processes that are uniquely involved with a specific activity… I am suggesting,” the author continues “that the brain has all kinds of local consciousness systems, a constellation of them, that are enabling consciousness” (p. 65-6).
Gazzaniga arrived at this conclusion by way of observing that patients with certain types of brain damage do not report being conscious of their mental deficits. Let us begin with a primer. Most of us have heard that the left hemisphere of the brain receives information from and controls the right side of the body, while the right hemisphere of the brain receives information from and controls the left side (which is why stroke victims who sustain damage to one of their brain hemispheres will often lose the ability to control the opposite side of their bodies). When it comes to our eyes, however, this is only partly right. More accurately, each eye splits the visual field out in front of us in two, and sends the information from the right visual field (via an optic nerve) to the left brain, and the information from the left visual field (via a separate optic nerve) to the right brain. So all of the information from the right visual field (from both eyes) goes to the left brain, while all of the information from the left visual field (again from both eyes) goes to the right brain (p. 54).
Now, people who have sustained damage to the optic nerve that carries information from one half of their visual field to the visual processing center in the brain have a blind spot over that half of their visual field. As we would expect, these patients are aware that they have a blind spot. They may say something to the effect of “hey, I can’t see anything on my left side, what’s going on?” (p. 65). Likewise, people who have sustained damage to the part of the brain that processes visual information from one half of their visual field also have a blind spot over that visual field. However, these patients are unaware that they have a blind spot. They can’t describe anything that is going on in one half of their visual field, but it does not appear to them as though anything is wrong: they are simply not aware of their mental deficit (p. 65).
The same phenomenon occurs with other brain modules as well, and often leads to some very strange effects. For instance, patients who have suffered damage to a nerve that carries information from a body part to the part of the brain that processes the position and location of that body part (located in the parietal cortex), report that they are unable to tell where that particular body part is, or what it is doing (p. 96). On the other hand, patients who have sustained damage directly to the parietal cortex report no such problem. Instead, they often deny that the body part in question is even theirs, and bizarrely say that it belongs to someone else instead! Even people who are not in the room!! (p. 96) (Footage of this condition is available here [once you get to the page you must go to Episode 1, Part 5 and skip ahead to the 1 minute mark—the footage is roughly 4 mins. long, but the segment continues for another 5 mins.]): http://topdocumentaryfilms.com/phantoms-in-the-brain/ (This phenomenon deserves more attention and will receive it in a subsequent section).
What could account for people being unaware (or in denial) of their own mental deficits? According to Gazzaniga, this can only be explained if consciousness occurred directly at the site of the module in the brain where each particular function takes place—and not at some single location separate from the modules themselves. The logic is as follows: if consciousness occurred at some single location, it would have to collect information from the other parts of the brain and then assimilate it into conscious experience. If this were the case, consciousness would recognize that it is missing information from a particular location in the brain if this area were to be damaged, and hence be aware of a mental deficit; just as the mind is aware of the mental deficit when either an optic or sensory nerve is damaged. Because this does not occur in patients who have sustained damage to particular parts of their brain, it must not be the case that the different brain modules are sending information to some central location to be assimilated into consciousness. Instead, it must be the case that consciousness occurs directly in the module where each separate function takes place. Accordingly, Gazzaniga claims that “consciousness is distributed everywhere across the brain… conscious experience is the feeling engendered by multiple modules, each of which has specialized capacities” (p. 63).
If Gazzaniga is correct then consciousness is not so much a single unified experience, but a collection of separate conscious experiences occurring at different locations in the brain. But if this is the case, then wouldn’t it feel as though we have multiple consciousnesses? Not necessarily. According to Gazzaniga, just one conscious experience captures your attention at any given time: “whichever notion you happened to be conscious of at a particular moment is the one that comes bubbling up, the one that becomes dominant. It’s a dog-eat-dog world going on in your brain with different systems competing to make it to the surface to win the prize of conscious recognition” (p. 66). Again we may ask, though, is it not necessary for one particular system to control which conscious experience captures our attention at any given moment? Isn’t there a need for a General to take charge of the situation, and dictate what makes it into consciousness? For Gazzaniga the answer, again, is no. According to him, consciousness works like many other complex systems that emerge out of simpler component parts: it is self-organizing. In Gazzaniga’s own words “while hierarchical processing takes place within the modules, it is looking like there is no hierarchy among modules. All these modules are not reporting to a department head, it is a free-for-all, self-organizing system” (p. 70). (More on this below.)
5. The Neuroscience of Our Inner Voice
So what we are left with is a brain that consists of several automatic modules that incorporate conscious awareness in their operations, and which are self-organized into a system that allows for only one of these conscious experiences to become dominant at any given time: “our conscious awareness is the mere tip of the iceberg of nonconscious processing. Below our level of awareness is the very busy nonconscious brain hard at work” (p. 68). The nonconscious brain includes not only homeostatic mechanisms such as heart, lung and temperature regulation, but “automatic visual and other sensory processing… positive and negative priming processes… coalitionary bonding processes… cheater detection processes, and even moral judgement processes (to name only a few)” (p. 68).
Things are not looking so good for the idea that there is a single ‘I’ in control. Rather, it is looking like this ‘I’ is an illusion that emerges out of the unconscious workings of the brain. Why, then, we may ask, do we experience the world as though this ‘I’ is unified and in control? In order to answer this question we must return to a particular brain module that we introduced earlier: the language center. According to Gazzaniga, the language center, which he calls the interpreter module, works to weave together all of the information from the environment and from the separate parts of the brain into a single coherent narrative: “the left-brain interpreter creates order out of the chaos presented to it by all the other processes spewing out information… it takes input from other areas of our brain and from the environment and synthesizes it into a story” (p. 88). Since the story that the interpreter module weaves is both coherent and unified, it appears to us as though our consciousness is unified.
Now surely, we would think, ‘we’ are in control of the interpreter module. Not so fast. The evidence seems to indicate that even the interpreter module is automatic and beyond our conscious control. Gazzaniga himself gained recognition for shedding light on the inner workings of the interpreter module in the 1960’s, when he began performing experiments on split-brain patients (p. 51).
Split-brain patients are people who have had their corpus callosum severed—the corpus callosum is the structure that connects the two brain hemispheres together, and allows the two hemispheres to communicate with one another via neuronal connections. Severing the corpus callosum is a procedure that is sometimes performed on epileptics to stop severe seizures. It was discovered that this dramatic procedure would work when an epileptic in the 1940’s developed a tumor over their corpus callosum, resulting in the halting of their seizures (p.53).
Incredibly, initial tests on split-brain patients gave the impression that severing the corpus callossum produced no adverse side effects whatsoever (p. 54). However, Gazzaniga designed a host of clever experiments that revealed that the procedure did, in fact, produce a few glitches. As mentioned earlier, information from the right visual field is sent to the left hemisphere of the brain and vice versa. The information gathered from each hemisphere is then shared with the other via the corpus callosum. Therefore, when the corpus callosum is severed the information cannot be shared.
Gazzaniga exploited this fact to make some very intriguing discoveries. In one experiment, Gazzaniga would present a split-brain subject with two separate images, one occupying only their right visual field, and the other occupying only their left. Gazzaniga discovered that split-brain patients could say what showed up in their right visual field (since it was passed to their left brain, where their language center was housed), but that they could not say what showed up in their left visual field (since the visual information sent to the right hemisphere was not allowed to make it across to the language center on the left). Split-brain patients do not experience a blind spot in their left visual field, however. As with patients that have suffered damage to the area of the brain that processes information for one of their visual fields, split-brain patients are unaware of their blind spot: they experience the world as though they have a full visual field.
Later tests revealed, however, that though split-brain subjects could not say what showed up in their left visual fields, they were nonetheless conscious at some level of what was there. For instance, when these subjects were subsequently presented with a range of objects that were more or less related to the original image in their left visual field, they could use their left hand to point to the most appropriate one! So if a snow scene was flashed up in their left visual field they could not say what was there, but when they were later presented with such objects as a tree, a lion, a diamond, a snow shovel, and a chicken, they could use their left hand to point to the snow shovel!! (p. 82).
If the split-brain patients could not say what was going on in their left visual fields, how did they explain their actions? This is where things get really strange. Here is an example of what happened. Gazzaniga flashed up a picture of a chicken claw in a subject’s right visual field, and a picture of a snow scene in their left. When Gazzaniga asked the subject what they saw they replied that they had seen the chicken claw but nothing else. Gazzaniga then presented them with a range of objects such as those mentioned above: a tree, a lion, a diamond, a snow shovel, and a chicken, and asked them to point to the most appropriate one. With their right hand they pointed to the chicken, and with their left hand they pointed to the snow shovel. Then, when Gazzaniga asked the subject why they pointed to the objects that they did, here was the response: “oh that’s simple, the chicken claw goes with the chicken… and you need a shovel to clean out the chicken shed” (p. 82). In other words, the subject’s interpreter module made up a story about the person’s actions that best fit what it was aware of (the chicken claw but not the snow scene), and in doing so completely misinterpreted the true reason behind the action of their own left hand.
In a similar scenario, Gazzaniga flashed the word ‘bell’ to the right brain of a split-brain subject, and the word ‘music’ to their left. The subject reported that they had seen only the word music. Then, when asked to use their left hand to point to one image among a number of options, the subject pointed to a bell, even though, as Gazzaniga puts it, “there were other pictures that better depicted music” (p. 83). When asked why they had pointed to the image that they did the subject replied “well, music, the last time I heard any music was the bells banging outside” (p. 83).
It appears that the interpreter module is so eager to make sense out of the world that it will force an explanation on things (including the individual’s own actions) even when the information that it has access to is far short of what is needed to get at the truth. Another experiment revealed that this fudging of explanations occurs even with regard to accounting for our emotional responses. For instance, Gazzaniga flashed a scary picture of a man being pushed into a fire to the left hemisphere of a split-brain patient. The subject reported that she had not seen anything, but when asked about her emotional state, she said that she suddenly felt frightened and apprehensive. When asked why, the subject responded “‘I think maybe I don’t like this room, or maybe it’s you, you’re getting me nervous’. She then turned to one of the research assistants and said ‘I know I like Dr. Gazzaniga, but right now I’m scared of him for some reason’” (p. 87). (Footage of these fascinating experiments is available here)
All of this makes it look very much like the interpreter module in our brains is just another automatic process that we are not entirely in control of. Equally frightening, it reveals that the stories that our interpreter module makes up to explain our experiences, emotions, and even our actions, are limited to what it is conscious of, which is often well short of the truth. You will recall the story told earlier of the patients with damage to their parietal cortex who denied that one of their body parts was theirs, and even claimed that it belonged to someone else instead. As it turns out, this bizarre misperception may have something to do with the interpreter module creating a story to account for an otherwise inexplicable phenomenon. Since these patients sustained damage to the part of the brain that processes information with regard to where a particular body part is located, the individual does not experience that body part as being theirs at all. The brain must therefore make up a story to account for this alien body part in its midst. As outlandish as the story that it creates is, it nevertheless clears up the feeling that the body part in question is not their own. In light of these findings, it makes us wonder how accurate are the conscious explanations that we give for justifying why we do what we do, and whether we can ever be fully aware of the true reasons behind our own behaviour. Gazzaniga sums up the situation thus: “that YOU that you are so proud of is a story woven together by your interpreter module to account for as much of your behaviour as it can incorporate, and it denies or rationalizes the rest” (p. 108).
6. The Neuroscience of Free Will
From here, the prospects of preserving a singular ‘I’ in control of our thoughts and actions gets even worse. Particularly damning are the results of a series of experiments performed by Benjamin Libet at the University of California—San Francisco. Libet used an MRI machine to show that the brain makes a decision to act before the person is even consciously aware of their decision (p. 128)! Indeed, Libet could even use the machine to predict what subjects would do before the subjects themselves ever knew!! (Footage of this fascinating experiment is available here [4 mins.]: http://www.youtube.com/watch?v=IQ4nwTTmcgs The full documentary from which this footage is taken is available here [50 mins.]) http://documentarystorm.com/category/psychology/page/3/
These experiments make it look like very much like our decisions and actions are not under ‘our’ conscious control, but are instead the result of automatic brain work. As Gazzaniga puts it “if actions are initiated unconsciously, before we are aware of any desire to perform them, then the causal role of consciousness in volition is out of the loop: conscious volition, the idea that you are willing an action to happen, is an illusion” (p. 129). However, Gazzaniga denies that this is actually what is going on here. Indeed, Gazzaniga maintains there is a way to preserve both the findings of neuroscience and the concept of a free will, and hence human agency. In order to appreciate how, we must return to what we learned earlier about how separate brain modules self-organize to produce a single stream of consciousness.
According to Gazzaniga, it is true that our single stream of consciousness emerges out of neurochemical activity in the brain. However, he denies that consciousness is a mere lifeless by-product of neurochemical activity. Instead, he argues that once consciousness emerges it takes on a life of its own, replete with properties that do not exist at the level of neurons, and operating according to laws that are different from those governing neurochemical activity (p. 130). The properties and laws pertaining to consciousness are so novel and far removed from those associated with their underlying neurons that they cannot even be predicted by a full analysis of these neurons (p. 130, 134-6). Thus consciousness is a completely novel phenomenon operating at a different level of organization from the neurons out of which it emerges. In plain terms, consciousness is more than the sum of its parts.
That consciousness has a life of its own can be seen from the fact that once it emerges out of neurochemical activity it is then capable of influencing future brain and mental states, thus demonstrating that it is capable of having a causal effect on the world (and proving that it could not be a lifeless by-product of neurochemical activity, but is instead an objective entity unto itself). Gazzaniga sums up the situation thus: “we humans enjoy mental states that arise from our underlying neuronal, cell-to-cell interactions. Mental states do not exist without those interactions. At the same time, they cannot be defined or understood knowing only the cellular interactions. Mental states that emerge from our neural actions do constrain the very brain activity that gave rise to them. Mental states such as beliefs, thoughts, and desires all arise from brain activity and in turn can and do influence our decisions to act one way or another” (p. 107).
7. The Principle of Emergence
Before we go any further it should be granted that this may sound like a bit of a fishy proposition. However, there is in fact plenty of precedent for this type of phenomenon elsewhere in nature. In fact, it may just be the case that the process that Gazzaniga is talking about here underlies all natural phenomena. The process in question is captured by the sub-field known as complexity theory, and the principle of emergence. Emergence occurs when simple entities are arranged in particular configurations to produce a complex system that exhibits entirely different properties from those present in the parts out of which it is created. As Gazzaniga explains “emergence is when micro-level complex systems that are far from equilibrium… self-organize into new structures, with new properties that previously did not exist, to form a new level of organization on the macro level” (p. 124).
A simple example of emergence is the phase shift from water to ice (p. 125-6). Water has certain properties that result from the peculiar interaction between hydrogen and oxygen. When water is frozen to form an ice crystal the interaction between the hydrogen and the oxygen changes to produce a different set of properties at the macro level. However, the properties and structure of the ice crystal cannot be predicted by analyzing the conglomeration of hydrogen and oxygen, nor can it be discerned by way of analyzing the hydrogen and oxygen in isolation. All we can say is that the properties of the ice crystal emerge out of the peculiar configuration of its component parts, and in such way that is theoretically unpredictable.
An example of emergence that is more useful for our discussion here is that of traffic. Traffic is a phenomenon that emerges when numerous individual cars interact. However, the laws that govern patterns of traffic are far different from the laws that govern automobiles. What’s more, we cannot predict the laws that will govern traffic patterns by looking at individual cars (p. 136). So traffic and cars exist at two very different levels of organization. Nevertheless, traffic phenomenon does end up influencing the behaviour of individual cars. In the same way, Gazzaniga is suggesting, consciousness emerges out of neurons that exist at a lower level of organization than itself, but does end up having a causal influence on these neurons.
As mentioned earlier, emergence can be seen virtually everywhere in nature (p. 140). To start with, sub-atomic particles have certain properties and operate according to certain laws (covered by quantum physics), but self-organize into atomic particles that exhibit new properties and operate according to different laws (covered by standard physics). Atomic particles in turn self-organize into elements and compounds that exhibit still newer properties and operate according to still different laws (covered by chemistry). Certain elements in turn self-organize into self-replicating cells (whose properties and laws are covered by biology). Certain self-replicating cells in turn self-organize into central nervous systems (or brains) (whose properties and laws are covered by neuroscience). Some types of central nervous systems in turn self-organize into minds (whose properties and laws are covered by psychology). And finally, organisms equipped with minds in turn self-organize into complex social groups (whose properties and laws are covered by social psychology, sociology, anthropology, history, economics etc.). In each case the new set of phenomenon at a higher level of organization can and do have a causal effect on the entities at any of the lower levels, and can in turn be influenced by them. It operates as one giant feedback system.
8. Social Interaction and the Emergence of Freedom and Responsibility
The last level of complexity mentioned in the previous paragraph was that of the social group made up of numerous individuals and their minds. It is at this level of complexity, according to Gazzaniga, that the phenomenon of freedom and responsibility emerge. Indeed, Gazzaniga maintains that the interaction between individuals produces a social world wherein the concepts of agency and responsibility take hold: “when more than one brain interacts, new and unpredictable things begin to emerge, establishing a new set of rules. Two of the properties that are acquired in this new set of rules that weren’t previously present are responsibility and freedom” (p. 136). These properties emerge, Gazzaniga continues, because individuals living in groups enter into certain agreements and contracts with one another, the terms of which can place a check on their intentions. “My contention”, Gazzaniga explains, “is that ultimately responsibility is a contract between two people rather than a property of a brain, and determinism has no meaning in this context. Human nature remains constant, but out in the social world behaviour can change. Brakes can be put on unconscious intentions” (p. 216). In other words, just because freedom and responsibility do not exist at the level of neurochemistry does not mean they do not exist. Rather, they emerge at a higher level of organization, and are just as real as sub-atomic particles, or neurons, or the social interactions out of which they emerge. Proof of this comes from the fact that freedom and responsibility can be experienced and observed just as readily as these other types of phenomenon (p. 134).
9. Determinism Strikes Back
So for Gazzaniga, the phenomenon of freedom and responsibility can be saved, and therefore, it is not a contradiction for us to hold people accountable for their actions. However, it is questionable whether Gazzaniga’s arguments would persuade a staunch determinist. For the determinist may grant that the mind emerges from neuronal activity, and may even grant that the mind takes on a life of its own when it does so, and is capable of having a causal effect on the neurons out of which it emerges. Yet the determinist may still deny that the mind is free. For despite all of this, he will point out, the mind still operates in a lawful, non-random way, and the laws according to which the mind operates are in no way chosen by the individual minds under their sway. In other words, even though the mind may not be determined by the neurons out of which it emerges, it is still determined by the specific laws that obtain at its own level of organization. As such the determinist may agree that reductionism needs to be thrown out, and yet deny that determinism must be thrown out with it. Therefore, no free will, and holding people accountable for their actions is still a problem.
10. Rescuing Accountability from the Determinist Trap
Nevertheless, even if, in the final analysis, we are not able to rescue human freedom, we may still be able to justify the practice of holding people accountable for their actions (such as by punishing them for certain acts). All we need to do this is to accept two propositions. First, society is a better place the less criminal activity there is; and second, the threat of punishments (such as incarceration) leads to less criminal activity. With regards to the first proposition, the idea that society is a better place the less criminal activity there is strikes me as a no-brainer (I will not bother to get into the philosophical arguments here, at any rate). Indeed, even if we are determined to believe that society is better off with less criminal activity, and do not believe it of our own free will, this in no way compromises the legitimacy of the belief. Just as my believing that I am determined to want to be happy in life in no way makes me conclude that my happiness is therefore a useless goal; for my belief in determinism in no way removes the subjective feeling that my own happiness is a good thing, which is all that is necessary for hanging on to the belief that it is worth pursuing.
With regards to the second proposition—that the threat of punishments leads to less criminal activity—our intuitions should once again tell us that this is most certainly true. Just think: do you slow down when you see the cops? However, we need not only rely on our intuitions here, for, as Gazzaniga explains, “both theoretical models and experimental evidence show that in the absence of punishment, cooperation both in large and small groups cannot sustain itself in the presence of free-riders, and collapses. In order for cooperation to survive, free-riders must be punished. If you take accountability out of the network, the whole thing collapses” (p. 214). Incidentally, the fact that people respond to the threat of punishments in no way disproves determinism. For determinism does not necessarily imply that each of us is destined to act as we do regardless of the circumstances. Rather, it implies only that a person’s actions are determined based on whatever factors are present, which includes not only biological dispositions, but environmental factors as well, such as the laws of physics, as well as the law of lands.
So if people’s behaviour can be shaped by the threat of punishments, and society is a better place when there is less criminal behaviour, then we should have no problem with holding people accountable for their actions—even if we do believe that people are not entirely free in their behaviour. Nevertheless, the idea of punishing people for actions that they are determined to commit may still make us a bit uncomfortable, for it does still seem unfair to the individuals who end up being punished. Interestingly, this reaction of ours appears to come from the nature of our innate sense of fairness and justice. That is, we naturally tend to think that people should be punished as just deserts for their crimes, and not for the utilitarian purpose of preventing further crimes (p. 209-11). If people cannot truly be considered responsible for their actions, then it seems to us as though the idea of just desserts makes no sense, and therefore, it seems wrong to punish them—even if this would lead to less crime in the future.
As it turns out, there is a very good reason why our sense of justice takes this form. In the course of our evolutionary history, reaping the benefits of cooperation required that we deter free-riders from taking advantage of our cooperative overtures (since, as we have seen above, free-riders ruin cooperative endeavours). An excellent way to deter free-riders, of course, is to retaliate against them when they take advantage of you. However, retaliating against free-riders can be dangerous, because you run the risk of being injured in the process (by the very person whom you are trying to punish). However, if you are deterred by this utilitarian consideration then you will not retaliate against the free-rider, and whatever cooperative endeavour you were engaged in will collapse—and this is a far worse alternative than the risk of retaliating against the free-rider in the first place. So it appears as though evolution equipped us with a mechanism that favoured a desire to retaliate against a free-rider that was unconditional in nature, and unsullied by utilitarian considerations. To be precise, evolution equipped us with a belief that free-riders should be punished as just desserts for their actions, and not out of any consideration of the utilitarian effects of this punishment. Paradoxically, then, in order for our sense of justice to have the utilitarian effect of making cooperative endeavours possible, it had to be unconditional in nature, and not be influenced by utilitarian considerations.
Whatever the reason behind our retributive sense of justice, one thing seems certain, and that is that neuroscience will continue to yield findings that seem to be at odds with our feeling that we have a free will and are in control of our thoughts and actions. If Gazzaniga and those like him are unable to convince us that these findings do not in fact threaten free will, we may need to give up our retributive sense of justice in favour of a fully utilitarian sense of justice instead. Unless, of course, future findings and technologies allow us to deal with these issues in a more intuitively attractive way.
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