Tuesday, November 26, 2013

Just Neurons?

Neuroessentialism is the belief that you, your mind, your identity, are essentially just your brain. It gets touted as an example of how science has triumphed, once again, over superstitions of the past - your soul hasn't died, it was just an illusion! Created by the brain. With memory, sensation, speech, and just about every other human attribute found to be located in one gyrus or another, it seems like there isn't anything left that could be outside of the brain. Francis Crick referred to this as the “astonishing hypothesis[1],” and while Stephen Pinker pointed out that for most neuroscientists this idea hardly warranted much astonishment[2], what might be more astonishing is how quickly the idea is bleeding out of the laboratory into popular media.  The basic philosophical foundations of this notion have been around for a long time (as mentioned on the [highly entertaining] podcast “very bad wizards,” we've known for a long time that when you remove the head, the mind ceases to function. Grant Gillet mentions that even Aristotle held that the mind emerges as function of the body, rather than a separate spiritual entity that somehow inhabits the body).  However, the recent attention that neuroscience has been getting (especially with the advent of fMRI, which enabled a huge number of studies on healthy, awake humans) appears to have made this an easier pill for the public at large to swallow. Dr. Peter Reiner has even gone as far to document the rise of neuroessentialism and has begun to map out the potential positive and negative effects of this cultural shift[3].

A distant relative of the brain-in-a-vat: the brain-in-a-hat.  "I am a brain, Watson. The rest of me is a mere appendix. Therefore, it is the brain I must consider." A very neuroessentialist sentiment of Sherlock Homes, in The Adventure of the Mazarin Stone by Sir Arthur Conan Doyle.  Image from here.

With the rise of any sort of public awareness, we should expect there to be reactionaries who warn us about going too far with our new idea and neuroessentialism is no different. Rather than defending old arguments in the face of overwhelming experimental evidence, these thinkers instead point cautiously forward and advise us to make our claims about the mind carefully, rather than jump on the neuro-bandwagon.  I'd like to display two of these recent, anti-essentialist thinkers here.  Both argue what might be considered further expansions of Clark and Chalmers' extended mind hypothesis[4]--which itself argued that pen & paper, computers, (and today, cell phones) could all be considered as vital components of cognitive processes, and thus as part of the mind.   

Walter Glannon, in his 2009 Neuroethics article "Our Brains are Not Us" tackles the problem of what he calls "neuroreductionism"- which with all the talk about scientific reductionism going on, certainly sounds worse than innocent "neuroessentialism."  The position that Glannon takes against this neuroreductionism is referred to as "the distributed mind." The basic premise is to say that the mind is a result of the interaction between brain, body and environment, rather than just the result of neural activity.  At first glance, this claim (like the extended mind hypothesis itself) might seem like a licentious redefinition of the term 'mind.'  However, Glannon motivates this shift in focus, to see the mind as embodied (being situated in a body) and embedded (being situated in a vast physical, social, and at times adversarial environment), by suggesting that such an expanded view of the mind allows for a broader view of what might affect the health of that mind.  If we become too focused on the brain, we lose sight of the fact that the rest of the body, as well as the environment, can also be a place where mental health-affirming interventions take place.  Examples of this might be environmental changes in dealing with addiction, or the ability of psychotherapy to cause physical changes in the brain.

Glannon's argument for this shift towards a distributed mind is broken into two sections.  The first, to situate the mind as embodied, can be thought of as following Antonio Damasio's Somatic Marker Hypothesis[6].  The principle here is that many mental states, most notably many emotions, emerge through an interaction between the brain and body.  Likewise, there are a host of transactions between the brain and the rest of the body that affect mood and cognition, such as those mediated by the endocrine system (think of a life without adrenaline), the immune system (remember how groggy you feel when sick), and the proprioceptive sense (try to imagine life with tentacles rather than bony arms).

Thus, the famed "brain in a vat" thought experiment wouldn't be able to have emotions in any sense familiar to you or me, unless it was connected to a carefully simulated body.  While one might argue that such a simulation would simply be part of the simulated 'world' that this brain resides in, one should consider whether the human mind is more defined by human emotions (a capacity of the joint body and brain), or the ability to process visual information (a capacity of the brain).  In viewing the mind as the accumulation of many capacities, the skull becomes a much less authoritative bound on the physical implementation of the mind.

XKCD's take on neuroessentialism.  Comic by Randal Munroe, from here.

Once Glannon's mind has seeped out of the skull and permeated the rest of the body, it becomes much easier to envision it wafting through the pores and out into the world at large.  Glannon's point here is that the meaning of an experience is tied to the physical and social situation in which it occurred, not just to the brain states that represent it.  The claims related to this point are a bit contentious, however.  Glannon claims that information gleaned from brain imaging could never recreate a remembered scene, or identify how that memory influenced the person, or describe other subjective, qualitative aspects of that experience.  While this is, for the most part, true regarding the current generation of brain scanners (remember the 'dream imaging' technique that hit the news in 2011, 2 years after Glannon's paper?), in principle the information necessary for at least a qualitative description of these aspects of experience should be present in the physical brain (how else could we talk about such memories, long after the event has passed?).  Some advanced brain-interrogation device might thus be able to infer from the structure of the brain the speech it might produce when asked questions of the subjective nature discussed by Glannon, or even find subtle associations between potential stimuli (a strong connection between brain regions responsible for mounting a fear response, and parts of the olfactory cortex that deal heavily with garlic, for instance) that wouldn't necessarily be consciously available to the speaker. Glannon is apparently pointing to a different aspect of subjectivity, however, as he very clearly asserts that "Neuroimaging cannot read minds because the mind is not located in the brain."

Grant Gillett, in his 2009 article "The Subjective Brain, Identity, and Neuroethics," takes a very different approach to expanding the mind out from the brain.  Gillett starts from Aristotle to provide a definition for what makes one "human"- which Aristotle defined as a rational, social being.  This definition importantly includes both a physical aspect-the being itself, as well as a narrative aspect- the rational, social life of this being.  Thus, any sort of discussion about a person's mind cannot be divorced from the story of how that mind interacts with the world, and thus must include the physical, social, cultural, geographical relationships that the mind participates in (a list which Gillett includes under Husserl's term "the human life-world").  In Gillett's own words, “...for a neo-Aristotelian, the human psyche (soul) is neither a ghostly or spiritual inner core of a human being nor is it comprehensible in the language of physical objects, biology, and causal relationships yet it is (pun intended) the soul of ethics and therefore of fundamental importance for neuroethics.”  

The implications of this view are surprisingly far-reaching. Instead of thinking of how the brain orchestrates our experience, Gillett's language places the brain in the somewhat more passive role of being molded or inscribed by our experience of the world, by our story as a character in that world. This affirms the notion of an individual brain, whose response to physical interventions (such as stimulation, surgery, etc) depends on how this story has shaped the brain. Gillet then illustrates the power of this way of thinking by using it to reframe several neuroethical dilemmas, ranging from the rights of human embryos, patients with disorders of consciousness, the utility of the notion of 'free will,' the otherwise nonsensical notion of "fighting against one's damaged brain," and the effect of neurodegenerative diseases on human identity.  

Both Glannon and Gillett provide alternative conceptions to the "brain first" view of the human mind and identity that is held by the neuroessentialist position, without resorting to the arguments that neuroessentialism explicitly refutes (such as dualism). While these views might seem somewhat alien and even intrusive to those of us steeped in neuroessentialist thought (those of us studying neurons in culture, for instance, might be a little indignant at the implication for the human meaning of our work), I think that they may also help to cushion the shock of a culture that is just beginning to come to grips with the implications of neuroscience by reminding us that no matter what neuroscientists may tell you about your brain, you still have a great deal more than that making up your mind.  



Want to cite this post?

Zeller-Townson, RT. (2013). Just Neurons? The Neuroethics Blog. Retrieved on from http://www.theneuroethicsblog.com/2013/09/just-neurons.html



References

[1]Crick, Francis. Astonishing hypothesis: The scientific search for the soul. Scribner, 1995.
[2]Pinker, Steven. "The mystery of consciousness." Time Magazine 29 (2007): 55-70.
[3]Reiner, Peter B. "The rise of neuroessentialism." Oxford handbook of neuroethics. Oxford University Press, Oxford (2010): 161-175.
[4] Clark, Andy, and David Chalmers. "The extended mind." analysis 58.1 (1998): 7-19.
[5] Glannon, Walter. "Our brains are not us." Bioethics 23.6 (2009): 321-329.
[6] Damasio, Antonio. Descartes' error: Emotion, reason, and the human brain. Penguin. com, 2005.
[7] Gillett, Grant R. "The subjective brain, identity, and neuroethics." The American Journal of Bioethics 9.9 (2009): 5-13.

3 comments:

Peter B. Reiner said...

The Peter Wall Institute for Advanced Studies and the National Core for Neuroethics recently hosted a conference on this theme, followed by a public event, appropriately called "Am I my brain?" which is now online: http://t.co/bn4h2XHXuM

James Burkett said...

It seems, as you suggest, that Glannon's challenge to the "brain in a vat" merely pushes the necessary level of simulation of a world beyond mere electrical stimulation and into the realm of hormonal, biochemical, and nutritional stimulation. The fact that the inputs to the brain are somewhat more complex than electrical impulses doesn't seem like a challenge of principle so much as logistics.

Riley Zeller-Townson said...

Dr Reiner- thanks for the link! I'm sure many folks here will find the lecture very interesting, and I look forward to watching it myself.
James- at risk of combining Glannon's work with Gillet's, I think the change in Principle isn't that the brain/body interface is more nuanced than what the standard brain-in-a-vat experiment describes, so much as that human identity doesn't emerge from the brain itself, but from the brain's interactions with the world. At any one given time, you can't look at the brain in isolation and determine the identity of the human that possesses that brain- you would also need the rest of that human's body, and social life and all those other zillions of factors. Replacing your adrenal glands with a simulation would be just as intrusive as replacing your anterior cingulate cortex with a simulation. In both cases, the machinery which creates (exudes?) your identity as a human has been broken apart and partially artificially reconstructed- rather than maintained while the being plugged into different virtual worlds. Glannon goes as far to suggest that a matrix-style simulation would also be on that list- just like your adrenal glands and hippocampus, your social world also participates in generating your identity.