This post continues the discussion I began in “Alva Noe’s Philosophical Concepts 2.” This discussion has to do with Alva’s chapter titled, “Looking Into the Head.” I do recommend that you read this series of posts in order, beginning with 1.

The following discussion is based on information that can be found fully described in Alva Noe’s book, Out of Our Heads: Why You Are Not Your Brain and Other Lessons from the Biology of Consciousness. I urge you to read it.

To help elucidate the points Alva Noe is trying to make about his theory – that consciousness is not found in the brain alone and to preface what he is going to tell us about brain scans, he recounts two horrific health conditions that can happen to the brain:

Persistent Vegetative State (PVS): “…a disorder of consciousness in which patients with severe brain damage are in a state of partial arousal rather than true awareness. After four weeks in a vegetative state (VS), the patient is classified as in a persistent vegetative state.”[i]

Alva discusses one example of PVS where a woman who had suffered a stroke fell into a coma. She was diagnosed with PVS because she was unable to blink or track movement with her eyes. But it turned out that the stroke had damaged her cranial nerve which was preventing her from opening her eyes! Once they opened her eyes for her, she could follow their instructions. Oops! Later, she recovered and informed the doctors that she was able to hear all of their discussions about her condition and the back-and-forth about letting her die. Chilling! Alva mentions that this woman was lucky “…twice over. First, her mental presence was in fact detected. Second, she quickly recovered.”[ii]

Others, he mentions, have not been so lucky. He hen tells us about Belgian stroke patient ,Julia Tavalaro, who spent six years in a New York chronic care facility before one of her relatives noticed something that she reported to her doctors as conscious activity. Julia was suffering from something called:

Locked-in Syndrome: “Locked-in syndrome is a rare neurological disorder in which there is complete paralysis of all voluntary muscles except for the ones that control the movements of the eyes. Individuals with locked-in syndrome are conscious and awake, but have no ability to produce movements (outside of eye movement) or to speak (aphonia). Cognitive function is usually unaffected. Communication is possible through eye movements or blinking. Locked-in syndrome is caused by damage to the pons, a part of the brainstem that contains nerve fibers that relay information to other areas of the brain.”[iii]

Poor Julia spent six years being able to listen and understand everything that was going on around her, but unable to let anyone know she was conscious. Truly horrific! Fortunately, she also recovered. One can only imagine how many cases like this go undetected, leaving the patient in a very personal, isolated hell as the doctors and family allow them to slowly die.

Alva Noe goes through these examples to demonstrate that we cannot always determine the mental state of someone based solely on behavioral examples. People with PVS will often react to sounds, sit up, move their eyes, shout, or cry. This makes it difficult for many to quickly write off their family member as being a total vegetable. Folks with locked-in syndrome, however, can make it easier to judge that they are “not there,” because this disorder usually causes the patient’s face to become completely lifeless, expressionless, like a mask. We find it harder to make this judgement regarding someone with an expressive face.

Doctors require really good tools to help them figure out either of these disorders, as well as many other mental conditions and fortunately, several are at their disposal. You’ve probably heard of a few of these tools: positron emission tomography (PET); functional magnetic resonance imaging (fMRI); as well as electroencephalography (EEG).

All three of these tools, fortunately, tend to show that people with locked-in syndrome have normal brain activity, which is really lucky for those patients. Alva tells us that it is a different story when it comes to looking at the brain of someone with persistent vegetative state. In this case, the scans show an absence of normal brain imaging findings. But, asks Alva, is this enough for us to decide whether the patient is conscious or not? Would the absence of normal patterns of brain activity as shown by PET or fMRI be enough for you to satisfied that your loved one is a true vegetable? Hmm.

Alva goes through a lot more detail describing how patients with PVS can exhibit behaviors that make it difficult to know whether or not they are truly vegetables, even with the brain scans. In fact, says Alva, “…at present we are not even close to being able to use brain imaging to get a look inside the head to find out whether there is consciousness or not.”[iv]

I have to admit that, as someone who reads a lot of science magazine articles about brain scan experiments, this is not the impression one always gets from the experts. How many brain scan articles have I read that deal with showing – supposedly – different states of consciousness? More than four, for sure. This is important. We really need to know whether a patient is conscious or a vegetable and further, whether brain imaging can ever really help us decide. “It is disturbing…” says Alva, “…to learn that so far there are no theoretically satisfying or practically reliable criteria for deciding when a person with brain injury is conscious or not. At present, doctors and relatives have to deal with these questions without guidance from science or medicine.”[v] Remember Terri Schiavo?

It’s understandable how both doctors and scientists can get excited about the latest brain scanning technologies. After all, until these tools came along, they had to wait until a patient died to get a look inside their head. Unlike animal research, they couldn’t go digging around in the human brain due to ethical considerations and restraints. It’s also understandable, I think, how seeing the results of brain imaging can help drive and enforce the common belief in “the brain-based view of consciousness.” I mean, it’s right there before your eyes, right?

Alva tells us that there is no doubt these technologies “…will add to our ability to move forward in our quest to understand the conscious mind.”[vi] But, he cautions us as well, that this “…is all the more reason to pause and step back from the hype.”[vii] Why? Because “functional imaging raises important and still unresolved methodological problems.”[viii]

Certainly you have seen images online or on TV similar to the ones below:

 

 

 

 

 

 

 

Graphic above: fMRI scan.

 

 

 

 

 

 

 

Graphic above: PET scan.

Look vaguely familiar? Both PET and fMRI scans yield multi-colored images. The various colors correspond to different levels of neural activity, the pattern of the colors indicates areas of the brain where activity is believed to occur; and the brighter colors indicate higher levels of activity.

Alva points out something that wasn’t obvious to me (so much isn’t), but being a neuroscientists, it was obvious to him: that these scans are “…not actually pictures of the brain in action.”[ix] Wait, what? Actually, I thought these pictures were showing me exactly that – the brain at work! Wrong again. In explanation, Alva gives us a useful analogy:

“The scanner and the scientist perform a task that is less like gathering a photographic or X-ray image than it is like the process whereby a police sketch artist produces a drawing of a suspect based on interviews with a number of different witnesses.”[x]

Hmm. I never thought of brain scans like this and having thought about it, I have to say it has changed my perspective on this. What are the implications? Alva tells us that although these types of artist renderings can bear useful and valuable information about a criminal, “…they are not direct records of the criminal’s face.” Instead, they are a graphical rendering of various and perhaps even contradictory or conflicting reports of what different witnesses claim to have seen. This type of drawing is, at best, a conjecture rather than a recording or photograph of the criminal. This is similar, Alva tells us, to the way PET and fMRI work, as they do not display in any “…straightforward way traces of the psychological or mental phenomena. Rather, they represent a conjecture or hypothesis about what we think is going on in the brains of subjects.”[xi]

Alva asks us to consider the fact that we have a problem from the very beginning regarding how we are to decide which neural activity is relevant to the mental phenomena we suspect is going on in the brains of subjects. Scientists have to start with the assumption that every mental process corresponds to a neural process (he uses the example of a subject making a judgement as to whether two words rhyme or not).

So, let’s say we hook you up to a PET scanner to see what is happening in your brain when you decide whether or not two words actually rhyme. We will see a lot of neural activity in your head, but how do we decide which neural activity corresponds to the judgement that two words rhyme? The only way we can make this decision is if we know what your brain looks like when you are not making this judgement. In other words, we need some kind of baseline against which we can judge whether or not any deviation from the baseline corresponds to the neuronal activity. Alva tells us that “…Comparison provides the best method available for uncovering the areas of the brain that are critically involved in the performance of a cognitive function.”[xii] And while he believes that this method is “cogent” and “holds promise”, it is worth remembering that its reliability “…depends on a number of background assumptions, not all of which are unproblematic…”.[xiii] Ruh, roh!

What kind of problems is he talking about? Here he gets a wee bit technical, so let me try to summarize by saying that there is an assumption in this method that there is no feedback happening between what the brain is doing when we perceive the words and what the brain is doing when we make the rhyming judgement. This is a problem because apparently brain activity is a two-way street and thus feedback in our brains is common in a variety of situations. He uses perception as a specific example. There are, of course, neural pathways extending from our senses to our brains, but he tells us, “…there are even more neural pathways heading back out again.”[xiv] He says this should not be surprising if you think about how much easier it is to hear a sound that you are expecting than one you are not expecting. I had to think about this for a minute before I understood what he was saying, but it makes sense now.

He tells us that there is another assumption going on here, too: The assumption that we can break down the cognitive act itself into distinct, modular acts of perceiving the words (on the one hand) and judgments about whether they rhyme (on the other).”[xv] This, he says, is a “substantial” claim and cannot be taken for granted. (Carl Sagan once said that extraordinary claims require extraordinary evidence, I’m thinking the same concept applies here to a “substantial” claim.)

Alva is not trying to show us that comparisons are misguided or outright wrong, he’s just trying to point out that brain scanners don’t really show us what is going on when we listen and judge. And he doesn’t stop here since he believes that feedback issues pertaining to the brain and cognitive models are just “the tip of the iceberg.”

Continuing, he points out that both PET and fMRI scanners have very low spatial and temporal resolution. Localizing events in the brain using these technologies zeroes in on regions in the brain that are between 2mm and 5mm. That’s tiny, but the brain contains approximately 100 billion neurons, so even these small regions of the brain consist of hundreds of thousands of neurons. Thus, if there really is any specialization or differentiation going on with these cells, they will not show up in these scans.

Likewise, we can’t even be exactly sure when these neural events are happening. How’s that? Well, cellular events in the brain happen at a scale of thousandths of a second, but it can require much more time to detect and process signals for making images. Scientists know of this problem and get around it by having developed techniques for normalizing the data. This is done typically by simple averaging, which, due to the nature of averaging, involves the “loss of considerable information.”  Here, Alva tells us that just as American taxpayers have no set height or weight, averaged neural activities have no set location in any particular brain. This is the reason why brain scans are projected onto an “…idealized, stock brain,” just like the graphics above. The pictures we see in magazines or on TV are NOT snapshots of anyone’s particular brain in action, they are just images placed on stock photos.

And again, Alva doesn’t stop. He says that even if you put all of this to the side, it is still “…clear that there is no sense in which PET or fMRI pictures deliver direct information about consciousness or cognition.”[xvi] In fact, he says: “They do not even deliver direct representations of neural activity.”[xvii]

The reason for this is that PET and fMRI build their images based on the detection of (radio or lightwave) physical magnitudes that are believed “…to be reliably correlated with metabolic activity.”[xviii] He reviews how a PET scan works: A subject’s bloodstream is injected with a positron-emitting isotope and then PET detects the emission of gamma rays caused by the collision of positrons and electrons. Thus, the PET image carries indirect information about metabolic activity based on the direct measurement of a physical magnitude, “…which in turn, is supposed to correlate to significant mental activity.”[xix]

Alva tells us that at best, brain scans represent the mind “at three steps of removal.” First, they represent physical magnitudes correlated to blood flow; second, the blood flow is thus correlated to neural activity; and third, “…the neural activity is supposed to correlate to “significant mental activity.”

According to Alva, what we can conclude from this, if all the assumptions laid out above are accurate, is that the brain scan image may contain valuable and important information about neural activity pertaining to a cognitive process, but, we should not allow us to then be “…misled by the visual, pictorial character of these images,” because “brain scans are not pictures of cognitive processes in the brain in action.”

Let’s face it, current scientific research into consciousness takes for granted that the problem for science is to understand how it is that consciousness arises in the brain. It is simply unquestioned that the brain is where consciousness resides. Thus, the research continues, spinning its wheels, going nowhere fast, providing little true understanding of what we are.

In this first part of Alva’s book, he has forced us to ask ourselves whether our ability to explain consciousness and how our minds work is based on unquestioned assumptions. I think the answer clearly is, “Yes.” I hope I was able to do his work justice and that I may have helped you see this point of view, too.

The rest of Alva’s book is where he attempts to demonstrate that the brain is “not the locus of consciousness inside us, because consciousness has no locus inside us.” For Alva, our brain is critical to understanding how we work, but if we want to understand how the brain contributes to consciousness, we have to look at the brain’s job in relation to its larger non-brain body and the environment in which we find ourselves. He claims, and I am sorely tempted to agree, that it is a “body-and-world-involving conception of ourselves” that philosophy and the best new science should bring us to endorse.

My next post, Alva Noe’s Philosophical Concepts 4, will follow the lead found in another chapter of Alva Noe’s book, titled, “Conscious Life.” Here, Alva deals with the problem of “other minds.”

[i] Wikipedia.

[ii] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 15). Farrar, Straus and Giroux. Kindle Edition.

[iii] National Organization for Rare Disorders, Rare Disease Database.

[iv] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 18). Farrar, Straus and Giroux. Kindle Edition.

[v] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 19). Farrar, Straus and Giroux. Kindle Edition.

[vi] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 20). Farrar, Straus and Giroux. Kindle Edition.

[vii] Ibid.

[viii] Ibid.

[ix] Ibid.

[x] Ibid.

[xi] Ibid.

[xii] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 21). Farrar, Straus and Giroux. Kindle Edition.

[xiii] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 22). Farrar, Straus and Giroux. Kindle Edition.

[xiv] Ibid.

[xv] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 22). Farrar, Straus and Giroux. Kindle Edition.

[xvi] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 23). Farrar, Straus and Giroux. Kindle Edition.

[xvii] Ibid.

[xviii] Ibid.

[xix] Noe, Alva. Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness (p. 24). Farrar, Straus and Giroux. Kindle Edition.