The evolution of the human brain is a fascinating subject. The brain is arguably the most complex structure in the known (to us) universe, and is the feature that makes humanity unique and has allowed us to dominate (for good or ill) the fate of this planet. But of course we are but a twig on a vast evolutionary tree, replete with complex brains. From a human-centric perspective, the closer groups are to humans evolutionarily, the more complex their brains (generally speaking). Apes are the most “encephalized” among primates, as are the primates among mammals, and the mammals among vertebrates. This makes evolutionary sense – that the biggest and most complex brains would evolve from the group with the biggest and most complex brains.

But this evolutionary perspective can be tricky. We can’t confuse looking back through evolutionary time with looking across the landscape of extant species. Any species alive today has just as much evolutionary history behind them as humans. Their brains did not stop evolving once their branch split off from the one that lead to humans. There are therefore some groups which have complex brains because they are evolutionarily close to humans, and their brains have a lot of homology with humans. But there are also other groups that have complex brains because they evolved them completely independently, after their group split from ours. Cetaceans such as whales and dolphins come to mind. They have big brains, but their brains are organized somewhat differently from primates.

Another group that is often considered to be highly intelligent, independent from primates, is birds. Birds are still vertebrates, and in fact they are amniotes, the group that contains reptiles, birds, and mammals. It is still an open question as to exactly how much of the human brain architecture was present at the last common ancestor of all amniotes (and is therefore homologous) and how much evolved later independently. To explore this question we need to look at not only the anatomy of brains and the networks within them, but brain cell types and their genetic origins. For example, even structures that currently look very different can retain evidence of common ancestry if they are built with the same genes. Or – structures that look similar may be built with different genes, and are therefore evolutionarily independent, or analogous.

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My younger self, seeing that title – AI Powered Bionic Arm – would definitely feel as if the future had arrived, and in many ways it has. This is not the bionic arm of the 1970s TV show, however. That level of tech is probably closer to the 2070s than the 1970s. But we are still making impressive advances in brain-machine interface technology and robotics, to the point that we can replace missing limbs with serviceable robotic replacements.

In this video Sarah De Lagarde discusses her experience as the first person with an AI powered bionic arm. This represents a nice advance in this technology, and we are just scratching the surface. Let’s review where we are with this technology and how artificial intelligence can play an important role.

There are different ways to control robotics – you can have preprogrammed movements (with or without sensory feedback), AI can control the movements in real time, you can have a human operator, through some kind of interface including motion capture, or you can use a brain-machine interface of some sort. For robotic prosthetic limbs obviously the user needs to be able to control them in real time, and we want that experience to feel as natural as possible.

The options for robotic prosthetics include direct connection to the brain, which can be from a variety of electrodes. They can be deep brain electrodes, brain surface, scalp surface, or even stents inside the veins of the brain (stentrodes). All have their advantages and disadvantages. Brain surface and deep brain have the best resolution, but they are the most invasive. Scalp surface is the least invasive, but has the lowest resolution. Stentrodes may, for now, be the best compromise, until we develop more biocompatible and durable brain electrodes.

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Designing research studies to determine what is going on inside the minds of animals is extremely challenging. The literature is littered with past studies that failed to properly control for all variables and thereby overinterpreted the results. The challenge is that we cannot read the minds of animals, and they cannot communicate directly to us using language. We have to infer what is going on in their minds from their behavior, and inference can be tricky.

One specific question is whether or not our closest ancestors have a “theory of mind”. This is the ability to think about what other creatures are thinking and feeling. Typical humans do this naturally – we know that other people have minds like our own and we can think strategically about the implications of what other people think, how to predict their behavior based upon this, and how to manipulate the thoughts of other people in order to achieve our ends.

Animal research over the last century or so has been characterized by assumptions that some cognitive ability is unique to humans, only to find that this ability exists in some animals, at least in a precursor form. This makes sense, as we have evolved from other animals, most of our abilities likely did not come out of nowhere but evolved from more basic precursors.

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Humans (assuming you all experience roughly what I experience, which is a reasonable assumption) have a sense of self. This sense has several components – we feel as if we occupy our physical bodies, that our bodies are distinct entities separate from the rest of the universe, that we own our body parts, and that we have the agency to control our bodies. We can do stuff and affect the world around us. We also have a sense that we exist in time, that there is a continuity to our existence, that we existed yesterday and will likely exist tomorrow.

This may all seem too basic to bother pointing out, but it isn’t. These aspects of a sense of self also do not flow automatically from the fact of our own existence. There are circuits in the brain receiving input from sensory and cognitive information that generate these senses. We know this primarily from studying people in whom one or more of these circuits are disrupted, either temporarily or permanently. This is why people can have an “out of body” experience – disrupt those circuits which make us feel embodied. People can feel as if they do not own or control a body part (such as so-called alien hand syndrome). Or they can feel as if they own and control a body part that doesn’t exist. It’s possible for there to be a disconnect between physical reality and our subjective experience, because the subjective experience of self, of reality, and of time are constructed by our brains based upon sensory and other inputs.

Perhaps, however, there is another way to study the phenomenon of a sense of self. Rather than studying people who are missing one or more aspects of a sense of self, we can try to build up that sense, one component at a time, in robots. This is the subject of a paper by three researchers, a cognitive roboticist, a cognitive psychologist who works with robot-human interactions, and a psychiatrist. They explore how we can study the components of a sense of self in robots, and how we can use robots to do psychological research about human cognition and the self of self.

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How certain are you of anything that you believe? Do you even think about your confidence level, and do you have a process for determining what your confidence level should be or do you just follow your gut feelings?

Thinking about confidence is a form of metacognition – thinking about thinking. It is something, in my opinion, that we should all do more of, and it is a cornerstone of scientific skepticism (and all good science and philosophy). As I like to say, our brains are powerful tools, and they are our most important and all-purpose tool for understanding the universe. So it’s extremely useful to understand how that tool works, including all its strengths, weaknesses, and flaws.

A recent study focuses in on one tiny slice of metacognition, but an important one – how we form confidence in our assessment of a situation or a question. More specifically, it highlights The illusion of information adequacy. This is yet another form of cognitive bias. The experiment divided subjects into three groups – one group was given one half of the information about a specific situation (the information that favored one side), while a second group was given the other half. The control group was given all the information. They were then asked to evaluate the situation and how confident they were in their conclusions. They were also asked if they thought other people would come to the same conclusion.

You can probably see this coming – the subjects in the test groups receiving only half the information felt that they had all the necessary information to make a judgement and were highly confident in their assessment. They also felt that other people would come to the same conclusion as they did. And of course, the two test groups came to the conclusion favored by the information they were given.

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Scientists have just published in Nature that they have completed the entire connectome of a fruit fly: Network statistics of the whole-brain connectome of Drosophila. The map includes 140,000 neurons and more than 50 million connections. This is an incredible achievement that marks a milestone in neuroscience and is likely to advance our research.

A “connectome” is a complete map of all the neurons and all the connections in a brain. The ultimate goal is to map the entire human brain, which has 86 billion neurons and about 100 trillion connections – that’s more than six orders of magnitude greater than the drosophila. The human genome project was started in 2009 through the NIH, and today there are several efforts contributing to this goal.

Right now we have what is called a mesoscale connectome of the human brain. This is more detailed than a macroscopic map of human brain anatomy, but not as detailed as a microscopic map at the neuronal and synapse level. It’s in between, so mesoscale. Essentially we have built a mesoscale map of the human brain from functional MRI and similar data, showing brain regions and types of neurons at the millimeter scale and their connections. We also have mesoscale connectomes of other mammalian brains. These are highly useful, but the more detail we have obviously the better for research.

We can mark progress on developing connectomes in a number of ways – how is the technology improving, how much detail do we have on the human brain, and how complex is the most complex brain we have fully mapped. That last one just got its first entry – the fruit fly or drosophila brain.

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On the SGU we recently talked about aphantasia, the condition in which some people have a decreased or entirely absent ability to imagine things. The term was coined recently, in 2015, by neurologist Adam Zeman, who described the condition of “congenital aphantasia,” that he described as being with mental imagery. After we discussed in on the show we received numerous e-mails from people with the condition, many of which were unaware that they were different from most other people. Here is one recent example:

“Your segment on aphantasia really struck a chord with me. At 49, I discovered that I have total multisensory aphantasia and Severely Deficient Autobiographical Memory (SDAM). It’s been a fascinating and eye-opening experience delving into the unique way my brain processes information.

Since making this discovery, I’ve been on a wild ride of self-exploration, and it’s been incredible. I’ve had conversations with artists, musicians, educators, and many others about how my experience differs from theirs, and it has been so enlightening.

I’ve learned to appreciate living in the moment because that’s where I thrive. It’s been a life-changing journey, and I’m incredibly grateful for the impact you’ve had on me.”

Perhaps more interesting than the condition itself, and what I want to talk about today, is that the e-mailer was entirely unaware that most of the rest of humanity have a very different experience of their own existence. This makes sense when you think about it – how would they know? How can you know the subjective experience happening inside one’s brain? We tend to assume that other people’s brains function similar to our own, and therefore their experience must be similar. This is partly a reasonable assumption, and partly projection. We do this psychologically as well. When we speculate about other people’s motivations, we generally are just projecting our own motivations onto them.

Projecting our neurological experience, however, is a little different. What the aphantasia experience demonstrates is a couple of things, beginning with the fact that whatever is normal for you is normal. We don’t know, for example, if we have a deficit because we cannot detect what is missing. We can only really know by sharing other people’s experiences.

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Humans identify and call each other by specific names. So far this advanced cognitive behavior has only been identified in a few other species, dolphins, elephants, and some parrots. Interestingly, it has never been documented in our closest relatives, non-human primates – that is, until now. A recent study finds that marmoset monkeys have unique calls, “phee-calls”, that they use to identify specific individual members of their group. The study also found that within a group of marmosets, all members use the same name to refer to the same individual, so they are learning the names from each other. Also interesting, different families of marmosets use different kinds of sounds in their names, as if each family has their own dialect.

In these behaviors we can see the roots of language and culture. It is not surprising that we see these roots in our close relatives. It is perhaps more surprising that we don’t see it more in the very closest relatives, like chimps and gorillas. What this implies is that these sorts of high-level behaviors, learning names for specific individuals in your group, is not merely a consequence of neurological develop. You need something else. There needs to be an evolutionary pressure.

That pressure is likely living in an environment and situation where families members are likely to be out of visual contact of each other. Part of this is the ability to communicate at long enough distance that will put individuals out of visual contact. For example, elephants can communicate over miles. Dolphins often swim in murky water with low visibility. Parrots and marmosets live in dense jungle. Of course, you need to have that evolutionary pressure and the neurological sophistication for the behavior – the potential and the need have to align.

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I am not the first to say this but it bears repeating – it is wrong to use the accusation of a mental illness as a political strategy. It is unfair, stigmatizing, and dismissive. Thomas Szasz (let me say straight up – I am not a Szaszian) was a psychiatrist who made it his professional mission to make this point. He was concerned especially about oppressive governments diagnosing political dissidents with mental illness and using that as a justification to essentially imprison them.

Szasz had a point (especially back in the 1960s when he started making it) but unfortunately took his point way too far, as often happens. He decided that mental illness, in fact, does not exist, and is 100% political oppression. He took a legitimate criticism of the institution of mental health and abuse by oppressive political figures and systems and turned it into science denial. But that does not negate the legitimate points at the core of his argument – we should be careful not to conflate unpopular political opinions with mental illness, and certainly not use it as a deliberate political strategy.

While the world of mental illness is much better today (at least in developed nations), the strategy of labeling your political opponents as mentally ill continues. I truly sincerely wish it would stop. For example, in a recent interview on ABC, senator Tom Cotton was asked about some fresh outrageous thing Trump said, criticism of which Cotton waved away as “Trump Derangement Syndrome”.

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Gotta love the title of this paper: “A critical hit: Dungeons and Dragons as a buff for autistic people“. Dungeons & Dragons (D&D) is a tabletop roleplaying game where a small group of people each play characters adventuring in an imaginary world run by the dungeon master (DM). (That explanation was probably not necessary for the majority of readers here, but just to be thorough.) The game has just celebrated its 50th anniversary, which was even commemorated by official US stamps.

The game certainly has a very different reputation today than it did in the 70s and 80s. Back then it was seen as the exclusive domain of extreme geeks and nerds, mostly males who needed a distraction from the fact that they had no chance of finding a girlfriend. This was never true, but that was the reputation. In the 80s things got even worse, with D&D being tied to the “satanic panic” of that decade. The game was blamed, mostly by fundamentalist religious groups, for demon worship, witchcraft, and resulting in suicides and murder. I still remember when the school board in our town had a debate about whether or not the game should be banned from school grounds. The adults having the conversation had literally no idea what they were talking about, and filled the gaps in their knowledge with their own vivid imaginations.

In reality D&D and similar roleplaying games are perfectly wholesome and have a lot of positive attributes. First, they are extremely social. They are especially good for people who may find social interactions challenging or at least very demanding. While roleplaying you are in a social safe-space, where you can let aspects of your personality out to play. The game is also mostly pure imagination. Other than a few aids, like dice for random outcome generation, maps and figures, the adventure takes place in the minds of the players, helped along by the GM. The game can therefore help people develop social connections and social skills, and to learn more about themselves and close friends.

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