Philosophers are fascinated by the idea of zombies. This thought experiment of theirs supposes hypothetical beings that behave indistinguishably from humans but lack consciousness, so “zombies”. For some reason, if they existed, they think it would prove that there is something besides brain activity that produce subjective experience. I don’t get it, since I know that people can walk around, have conversations and deny recollection of conscious experience when told what the did after the fact.

Understanding the brain by what’s missing

One of my main tools as a neurologist is to examine patients with a deficit and figure out what part of the brain has been injured. It’s our tradition to understand how different parts of the brain participate in behavior by looking at patients where some function is missing or impaired and correlate function to the damaged area of the brain. For example, a small stroke in Broca’s area, located in the frontal lobe of the cerebral cortex (specifically the posterior part of the inferior frontal gyrus in Brodmann areas 44 and 45) causes what we call an expressive aphasia, a loss in fluency when trying to speak. If the injury is limited to this area, say by a small stroke, the patient understands speech perfectly well and can read text with no problems. So we conclude by seeing this correlation over and over again that the critical brain area for speech production resides in Broca’s area.

Of course that’s not to say that the ability to produce speech is only represented there like some computer subroutine. The content of speech is fed through Broca’s area from a wide range of other areas that know about the world. The decision to speak is being triggered from the prefrontal cortex, particularly the dorsolateral prefrontal cortex (DLPFC) which is associated with higher-order executive functions, such as decision-making, planning, and goal-setting. A lesion in the prefrontal cortex causes apathy and lack of initiative as was seen in patients who had the psychosurgery of prefrontal lobotomy in the 1940s. The surgery was replaced by a pharmacological dampening of the broader dopamine control system with antipsychotics.

The localization of consciousness

We now know that maintenance of consciousness is located in one particular brain network consisting of the cerebral cortex and the more deeply located structure called the thalamus. Now we need to be careful in separating this network which controls level of consciousness from the mechanisms that provide for the content of consciousness, the particular sensory channel being activated for conscious awareness. The level of consciousness is how conscious the person is, ranging from being asleep, being in a coma or being wide awake and attending to some aspect of the sensory environment.

While there are brain lesions with profound effects on the level of consciousness, we also have an array of drugs that we use to alter level of consciousness for medical procedures. These drugs are quite capable of creating the zombie the philosophers are always hypothesizing, that its to say, a person who looks awake and is behaving as if they’re conscious but lacking awareness of their actions.

There’s actually a choice of drugs to create zombies, all of which activate the GABA inhibitory neurotransmitter system in one way or another. Among them are alcohol, gamma-hydroxybutyrate (GHB), benzodiazepines (like valium, midazolam and many others used for anxiety or insomnia) and general anesthetics both inhaled (like halothane) and injectable (like propofol).

Selective effects of propofol on consciousness

In the neuroscience literature on level of consciousness, you’ll see the intravenous anesthetic propofol studied most commonly. That’s a matter of convenience and suitability. It’s easy to use infusions in animal and human studies, the dose is easily controlled by rate of infusion, and the effects are very rapid, both coming on and wearing off.

The effects of propofol on the cerebral cortex are most easily seen by EEG, a recording of voltage differences at the scalp which reflect the electrical activity of the neurons under the electrodes as conducted though the skull and scalp. In an awake person, the electrical waves are chaotic and fast, reflecting all of the fluctuating activity across the cortex as sensory information comes in, is reflected to association areas and motor activity initiated. Even though our awareness is limited to one channel at a time through attentional systems, there’s activity across all of the systems and they are talking to each other.

Start a propofol infusion and the activity starts to slow. The EEG analysis shows a drop in EEG frequency across the spectrum. With enough propofol, we can induce a profound coma to where the signal becomes very nearly flat. We do this clinically at times to treat brain trauma and uncontrollable seizures.

Zombies are an in-between state where awareness is lost

An awake person is interesting to interact with while someone in profound coma isn’t so engaging. But it’s the in between zone where we create a zombie. If you’ve ever had general anesthesia, whether with propofol or inhalation anesthesia, you’ve had the unique experience of having your mind suddenly switched off and then back on again in what seems subjectively like no time passing. Even though hours may have elapsed on the clock in the operating room, one second they’re wheeling you in, the next second you awake in the recovery room. Its a disturbing interruption of self that doesn’t happen when you’re drowsy or asleep.

So yes, many of us can subjectively confirm that these drugs turn consciousness off. You have no experience of anything during that time. The EEG is slowed, but the cortex is continuing its business without awareness. In fact, most electical recordings from neurons in the lab are done on anesthetized animals. I did that during my PhD studies. It turns out that light anesthesia has very little effect on information flow though the visual system or autonomic control system. Hubel and Weisels pioneering recording from the visual system where the found edge detection neurons, cortical columns and surround inhibition were all done in anesthetized animals. True, spontaneous behavior disappears so it can’t be studied, but most brain circuits function pretty normally, well enough that their basic characteristics can be studied.

Behavior during sedation without subjective awareness = Zombie!

But you’ll object that the anesthetized person, even though their cortex continues processing sensory symptoms is not a zombie since there’s no behavior. Well, at just the right level of infusion, a level often called “Twilight Sleep” by the medical profession, but more appropriately just “sedation”, you can ask the patient to perform simple tasks like squeezing your hand or giving short answers to questions. That much of the cortical processing for input and output is working. If sedation gets too light, you get the problem that spontaneous behavior returns but the patient is still not conscious. They’ll try to get off the procedure table or at least move around to get comfortable. Not good during a colonoscopy. It’s just that the frontal lobe system to trigger behavior is active enough to try to get out of bed, but the thalamo-cortical network for awareness and attention is selectively turned off by the propofol infusion.

Unfortunately, this state of being unconscious but behaving is not uncommon in the real world when alcohol, benzos or GHB is circulating in the blood and activating the brain’s GABA system. It’s not uncommon for people to drink to excess, take pills or even be slipped a dose of powerful sedative like GHB. They’ll continue to act like they are awake but, just like the state of anesthesia or sedation, have a gap in the continuity of their awareness suggesting that they were behaving, but not aware. Clearly some supervisory, attentional mechanisms are active when the drinker gets a ride home from the bar and awakens with a gap. You tell the drinker how much fun they had last night and they recall none of it.

Memory is consciousness is self identity

You may realize that we’ve ended up conflating continuous awareness with memory of awareness. Since the subjective report relies on recall, they can’t two can’t be untangled. And of course, knowing who you are, that you’re the same person this morning that went to sleep last night is dependent on memory.

Actually, turning of memory storage is another way to create a zombie pharmacologically. But as I’ll argue in the next posts, much of our day passes in the zombie state. Most of the time our brains attend to controlling behavior, processing sensory input and responding to the environment but without awareness of self. Most of the time, we don’t need be anything other than a zombie. It feels strange when self awareness is gone because of external causes like sedation, not when we disengage the mechanism ourselves.

My cycling and fitness activities are being enabled by a set of technologies that were not widely available a few years ago- online coaching through internet enabled analysis of power files and streaming fitness sessions monitored by a wearable measuring movement and heart rate.

20 years ago we started using heart rate monitors widely. Before that there was just subjective effort. With a few chips we could see inside ourselves and augment the experience by seeing another, physiological dimension. Now my bike has a power meter, so I can see my actual output and compare it to the physiological effect and the subjective effort. My experience of riding and ability to train is augmented. The winner of Tour de France last year was only 23. The cycling pros of the previous generations ascribe the rise of younger champions to their use of these technologies to skip the years of learning and slow builds that the previous generation had to go through.

The key is that you need to use the technology to achieve real personal goals, not just enrich tech platforms.

One concern is that a machine would not need to be more intelligent than humans in all things to pose a serious risk. “It’s something that’s unfolding now,” he said. “If you look at social media and the algorithms that choose what people read and watch, they have a huge amount of control over our cognitive input.”

Do you want to blindly give away your data to others and allow their algorithms manipulate us? Or seek real experiences augmented by technology? Do we live in the real, augmented world or in their “metaverse”

I’m hoping that Apple’s augmented or virtual reality device will be more along the lines of a way to enhance the experience of real or imagined worlds and not a way to enslave us in their artificial environment.

The Augmented Environment

One of my conclusions from studying how the brain interprets the world and how people actually make decisions is that the single most important decision we make is the choice of our environment. And by that I mean both physical and semantic environment. Who are the people we surround ourselves with? What are the books and websites we read? The key is that our beliefs strongly condition how the world occurs to us. We can’t decide in the moment how to react to the statement of a politician or writer.

In statistics, we call these beliefs “priors” that determine the probabilities we assign to events. We update those priors with new information all of the time, so the information we’re exposed to on an ongoing basis determine perception.

At the brain level, we can see this in the most basic forms of perception, like how we see ambiguous figures, for example here: Long-term priors influence visual perception through recruitment of long-range feedback

A computational model incorporating hierarchical-predictive-coding and attractor-network elements reproduced both behavioral and neural findings. In this model, a bias at the top level propagates down the hierarchy, and a prediction error signal propagates up.

It’s reasonable to extend this kind of biased perception extending to how we perceive what people say to us or their motives. If you believe you live in a violent environment or that some classes of people are inherently violent, your priors will influence your interpretation of the words and actions of everyone around you. No choice in the matter, because belief comes from experience and experience largely comes from environment.

The trouble is that in our augmented reality, we don’t experience much of the world at all. We read reports of the world and interpretations of events. That’s an overlay that we experience as part and parcel of the real world, even though it’s just an overlay providing an interpretation, augmenting the pure sensory event.

So choose your friends and your information sources carefully.

Note taking seems to be having one of its many turns as an internet topic. The world of analog journalling is flourishing, propelled by (mostly) Japanese stationary brands like Midori with its Traveler’s Notebook and the Hobonichi Techo, but some stalwart European and British brands like Rhodia and even Filofax. On the digital side there’s a new crop of back linking network note taking apps that join the still relevant categories of GTD task managers, plain text approaches, Wikis and Hypertext (like my favorite, Eastgate’s Tinderbox), and integrated note systems from Evernote to Ulysses to Markdown editors to the latest like Craft. And then there’s the handwriting on iPad apps like Notability and Good Notes. I almost forgot the emerging ePaper device category, which has tempted me a few times ((But I know that fountain pen and paper just works for me better than stylus on iPad and probably one of these cool, single purpose devices)).

I ask myself, “With all this note taking, where’s the shared content being shared?”

Lots of notes, lots of systems, lots of discussion. Not so much content coming back out of these notes outside of work product like academic publications, corporate reports and the commercial content universe of the internet which has replaced magazines and newspapers, but tends toward the slick and superficial.

I miss the individual voices of the early internet and it seems that all of this note taking should provide some path for sharing what we’re all learning outside of commercial sites.

An Appeal To Contribute

I often see mention of how Google/YouTube has turned the web into a closed system by controlling search and advertising. For a long time, its been noticeable how many searches return no real results on the first or event the second page. I get advertising, shopping and howto Youtube videos.

If I see real content it’s often a link to Reddit, a company support forum or, sometimes a post on Medium. In fact, I’ve subscribed to Medium because so often search results take me there. Since most of the web writing going on is on commercial sites selling courses or subscription content, even when I get sent to a content page, it’s often a teaser for some course or software. I rarely get linked to one of the sites I follow through RSS feeds via NetNewsWire. In fact, I’ll often add a word or two to the search to make sure that I get an answer from Thom Hogan on photography plus others who may have commented on his opinion.

Curiously, huge amounts of the internet are generally completely cut out of these searches- Twitter, Instagram, Facebook. And email subscription newsletters. And Substack. We’re in a world of walled gardens and click farms.

Sadly, this isn’t entirely the fault of the Machine Learning algorithms that now rule the world and decide how to rank the results on a Google search page. There’s definitely less for the search engines to point to and less interchange between web sites that leads to links an interest.

Where’s the useful content then?

Now I’ll admit my own guilt here. I lost the drive to create useful content here when that early blogging community dissipated. I do learn things I ought to be sharing. There’s a steady stream of traffic here, so I could contribute more. I read, take notes, come to conclusions. My notebooks are full, my blog is empty.

An example? Is it worth the cost to buy a 16GB M1 Mac or should I get the quickly available 8GB memory model? Once I found a few examples of limitations, it seemed clear that for my use, processing big RAW files in Photoshop with Nik filters, a 16GB upgrade was going to be worth it. And it is. I don’t have a suite of test results, but I did see how fast the Apple Silicon Photoshop beta processed gaussian filters to create the now infamous Orton Effect ((If you haven’t heard, the Orton effect is that glowy landscape look, taking over from the overdone HDR workflow (which is not at all natural looking!) as getting likes on Flickr. Previously, I participated in the oversaturated landscape movement, to my everlasting shame.))

Another one? Should I switch to editing this website with the WordPress Gutenberg editor or keep my existing MarsEdit staging workflow? It looks like it makes sense to do only early drafts in MarsEdit to take advantage of creating links and pulling in media from Photos, but then publishing is best out of the new WordPress interface. And it looks like there’s no reason to move off of WordPress to any other system.

Workflows. How to use tools. Hacks, tricks and lessons learned in the course of exploration and implementing. All interesting reads and worth sharing.

If I needed any evidence of the value of sharing useful lessons, I need look no further than the content that is seen here. By far, the most viewed page is How Bill Gates Takes Notes, which is a short piece about the tale of his using the Cornell note taking system during meetings. I wrote that page because I found it interesting and there was no where left on the web where it was ell documented. I also have some photography pages and note taking workflow pages that get a hit or two day. Mostly from Google based on questions asked about how to do something or what something is, bypassing all the shopping and YouTube content.

John Nernst at Everything Studies provides a long and thoughtful analysis of a discussion of a dangerous idea: A Deep Dive into the Harris-Klein Controversy. I think it’s worth a comment here as well.

As a neuroscientist and reader of all of these public personalities (Charles Murray, Sam Harris and Ezra Klein), I’ve followed the discussion race and IQ over the years. We know that intelligence, like many other traits like height or cardiovascular risk are in part inherited and influenced strongly by environment. Professionally, I’m interested in the heritability of complex traits like psychiatric disorders and neurodegenerative diseases. The measured differences in IQ between groups falls squarely in this category of heritable traits where an effect can be measured, but the individual genes responsible have remained elusive.

I’m going to side with Erza Klein who in essence argues that there are scientific subjects where it is a social good to politely avoid discussion. One can learn about human population genetics, even with regard to cognitive neuroscience without entering into an arena where the science is used for the purpose of perpetuating racial stereotypes and promoting racist agendas of prejudice. That the data has a social context that cannot be ignored.

Sam Harris, on the other side of the argument, has taken on the mantle of defender of free scientific discourse. He takes the position that no legitimate scientific subject should be off limits for discussion based on social objections. His view seems to be that is that there is no negative value to free and open discussion of data. He was upset, as was I, at Murray’s treatment at Middlebury College and invited Murray onto his podcast. Sam was said by some to be promoting a racist agenda by promoting discussion of the heritability of IQ in the context of race.

In fact, Ezra Klein joined the conversation after his website Vox published a critique of the podcast portraying Harris as falling for Murray’s pseudoscience. But that’s nothing new really; Murray surfaces and his discussion of differences in IQ between populations is denounced.

As one who knows the science and have looked at the data, it bothers me like it bothers Harris that the data itself is attacked. Even if Murray’s reasons for looking at group differences is to further his social agenda, the data on group differences is not really suprising. Group differences for lots of complex inherited traits are to be expected, so why would intelligence be any different than height? And the genes responsible for complex traits are being explored, whether its height, body mass index or risk for neurodegenerative disease. Blue eyes or red hair, we have access to genomic and phenotypic data that is being analyzed. The question is whether looking at racial differences in IQ is itself racist.

I’ve surprised myself by siding with Klein in this case. His explanation of the background is here and his discussion after his conversation directly with Harris is here. Klein convincingly makes the argument that social context cannot be ignored in favor of some rationalist ideal of scientific discourse. Because we’re human, we bring our cultural suppositions to every discussion, every framing of every problem. Culture is fundamental to perception, so while data is indifferent to our thought, the interpretation of data can never be free of perceptual bias. Race, like every category we create with language, is a cultural construct. It happens to be loaded with evil, destructive context and thus is best avoided if possible, unless we’re discussing the legacy of slavery in the United States, which I think is Klein’s ultimate point.

Since these discussions are so loaded with historical and social baggage, they inevitably become social conversations, not scientific ones. Constructive social conversations are useful. Pointless defense of data is not useful; we should be talking about what can be done to overcome those social evils. No matter how much Sam would like us to be rational and data driven, people don’t operate that way. I see this flaw, incidentally, in his struggle with how to formulate his ethics. He argues with the simple truth that humans are born with basic ethics wired in just like basic language ability is wired in. We then get a cultural overlay on the receptive wiring that dictate much of how we perceive the world.

Way back when, almost 20 years ago, I named this blog “On Deciding . . . Better” based on my belief that deciding better was possible, but not easy. In the 20 years that have passed I’ve learned just how hard it is to improve and how much real work it takes. Work by us as individuals and work by us in groups and as societies.

It's hard to believe how little we trust what we read in this age of the internet.

The US election of 2016 demonstrated just how profoundly our relationship to authority has changed. We're exposed to conflicting opinions from the online media. We hear facts followed by denial and statement of the opposite as true. Everyone lies, apparently. There's no way to make sense of this online world in the way one makes sense of a tree or a dog or a computer.

Perhaps relying on confirmation bias, we are forced to interpret events without resort to reasoned argument or weight of evidence. We have to fall back on what we already believe. You have to pick a side. Faced with a deafening roar of comments on Twitter, cable news, news websites, we shape what we hear to be create a stable, consistent worldview.

Welcome to a world of narrative where the truth is simply the story we believe. And pragmatically, it seems not to matter much. Believe what you will, since we mostly yield no power in the world.

So what am I to make of this nice new MacBook Pro that I'm using right now? Is it really evidence of Apple's incompetence or their desire to marginalize or milk the Mac during its dying days? Again, believe what you will, but I've got some work to do.