Archive for the 'Neuroscience' Category

Jul 18 2019

Neuralink To Begin Human Trials

Published by under Neuroscience

I’m still trying to figure out if Elon Musk is a mad genius or a supervillain. Perhaps that’s a false dichotomy. Seriously, I do like his approach – he has billions of dollars laying around, so he decides that we need some specific technology in order to build the future, and he builds a company dedicated to developing that technology. Wherever he sees holes, he tries to fill them.

SpaceX has been, in my opinion, his most dramatic success. He has pioneered the technology of reusable rockets, and anyone who has seen one of his falcon rockets landing vertically has to be impressed. Tesla cars are impressive as well, but from what I understand he still has to make the company profitable. I’m still skeptical about the hyperloop, but at least he’s trying. It all depends on how cheap he can make tunneling, and the real innovation may be in his Boring company.

Not all of his companies involve travel. He also wants to change humans, in order to ultimately keep up with the AI he thinks we will inevitably create. In 2017 he tweeted, “If you’re not concerned about AI safety, you should be. Vastly more risk than North Korea,” along with a picture declaring, “In the end, the machines will win.” The existential threat of AI is a separate question.

Now for most people, if you are worried about AI you talk about it with your friends and colleagues. Perhaps you have a blog where you can share your concerns with the world. But if you are Elon Musk you can start a 100 million dollar company designed to thwart the perceived threat. So that’s what he did.

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Jul 02 2019

Making Mini-Brains from Stem Cells

Published by under Neuroscience

A new report details the progress scientists have made in developing brain organoids from stem cells. They use human embryonic stem cells to culture neurons – brain cells. Lead author, Hideya Sakaguchi, describes the process:

“The team cultured the organoids for 70-100 days, dissociated them into single cells and then disseminated them into another culture dish. The disseminated cells created neuronal networks in a self-organized manner.”

Just by culturing individual neurons together, they spontaneously formed networks and some three-dimensional tissue structure, forming into layers similar to the layers seen in human cortex. Further, the networks of neurons demonstrated some coordinated firing. There was both spontaneous individual cell activity, as well as synchronized activity within networks of cells.

The result is not a brain, which is why it is called an organoid (often referred to as a mini-brain, but this is less technically accurate). What this demonstrates is the inherent properties of human brain neurons to spontaneously form tissue structure and to from neural networks that are functional. The cells are essentially trying to self-organize into a brain. They cannot fully do this, however, because there is a huge piece missing – sensory input and the feedback from output.

A human brain, even an infant brain, contains more information by orders of magnitude than is contained in all the genes that are involved in neurological function. The genes are not a blue print for a brain. Rather, the genes are a set of instructions, of behaviors, that if followed allow for the development of a fully formed brain. But that development requires more information – information from the rest of the body. This process continues after birth as babies develop their vision, hearing ability to move, eventually to walk, socialization, and language. If deprived of stimulation in these areas, the relevant part of the brain will not develop.

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Jun 27 2019

The Bystander Effect

Published by under Neuroscience

Social psychology is the study of how people behave in social situations, so it deals with the complex interactions between personality, culture, and social pressures on how we behave and in turn are affected by each other. I took a social psychology course in college and it really opened my eyes. This was one of the first courses I took that challenged my assumptions in a profound way, because there is a disconnect between our assumptions about how people think and behave and how they actual do when objectively observed. In this way social psychology (and psychology in general) is an important pillar of scientific skepticism.

As an example, there is a recent study that uses CCTV to monitor violent incidents in three cities, Amsterdam, Lancaster, and Cape Town. So these are real-life events, not staged for the study. The researchers counted how many times people intervened in such incidents, such as someone being pummeled on the ground by an attacker. First, think how you would respond in such a situation. Now also think about how the average person would respond. What percentage of the time do you think a bystander intervened? Was it the same or different in the various cities, which differ in terms of their crime and safety? If individuals fail to respond, why?

Your answers to these questions probably say more about you and the culture you live in than reality. This is the meta-finding of social psychology. We often are incorrect in our assumptions about what other people think, how other people behave, and what motivates other people. We also judge ourselves by a different set of rules than we judge others (the fundamental attribution error). Research also finds that understanding this is extremely empowering, and this is also something I found fascinating about social psychology. This was the first time I can remember that a little bit of knowledge empowered me to take greater control of my actions, rather than ride passively down the currents of subconscious psychological forces.

I am deliberately putting the link to the study and the results below the fold. When you’re ready, take a look.

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Jun 24 2019

Study on Visual Framing in the Presidential Debates

This week we will have the first primary debates of the presidential cycle, with two Democratic debates of the top 20 candidates (10 each night). A timely study was just published looking at the coverage of the different candidates in the 2016 primary debates of both parties. The results show a dramatic disparity in how different candidates were covered.

Unfortunately, the headline of the press release is misleading: Study Shows Visual Framing by Media in Debates Affects Public Perception. The study did not measure public perception, and therefore there is no basis to conclude anything about how the framing affected public perception. The study only quantified the coverage. But what they found was interesting.

They went frame by frame through the first two primary debates of both parties and calculated how much coverage each candidate had and what type – solo, split screen, side-by-side, multi-candidate shot, and audience reaction. This is what they found:

We likewise considered how much time the camera spent on a given candidate before cutting away by computing  -scores for each candidate’s mean camera fixation time (see Figure 3). This allowed us to see whether networks were visually priming the audience to differentially perceive the candidates as viable leaders. These data show that across the four debates, only Trump, specifically during CNN’s Republican Party debate, had substantially longer camera fixations (  ) than the other candidates (   to 1.84). During this debate, Bush (  ) was the only candidate besides Trump to have a positive z-score, providing modest support for our visual priming hypotheses concerning fixation time (H2). While for the Fox News debate, Cruz (  ) and Huckabee (  ) had substantially higher  -scores than the rest of the field, including Trump, their scores were well within the bounds of expectations. Likewise, on the Democratic side, neither CNN (   to 1.17) nor CBS (   to 0.89) gave a significant visual priming advantage to any candidate, although there were trends toward front-runners Clinton and Sanders having slightly longer than average fixation times during both debates.

Essentially, there was a lot of noise in the data, but only one significant spike above the noise – during the CNN debate Trump had significantly more camera time than the rest, with Bush also having greater camera time but not nearly as much as Trump. At the time they were the two front-runners in polling. Clinton and Sanders also had a trend towards more camera time in their debates, but not statistically significant.

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Jun 18 2019

Is Authenticity a Thing?

Authenticity is a tricky concept when it comes to people, and is increasingly being challenged both in psychology and even with regard to physical objects (with regard to objects, the value rather than reality of authenticity is questioned).  Writing for Scientific American, psychologist Scott Barry Kaufman deconstructs the psychological concept of authenticity nicely. But let’s start with a standard psychology definition of what this means:

Authenticity generally reflects the extent to which an individual’s core or true self is operative on a day-to-day basis. Psychologists characterize authenticity as multiple interrelated processes that have important implications for psychological functioning and well-being. Specifically, authenticity is expressed in the dynamic operation of four components: awareness (i.e., self-understanding), unbiased processing (i.e., objective self-evaluation), behavior (i.e., actions congruent with core needs, values, preferences), and relational orientation (i.e., sincerity within close relationships). Research findings indicate that each of these components relates to various aspects of healthy psychological and interpersonal adjustment.

My issue with this definition is that each of those components don’t necessarily add up to something greater than the sum of the parts. I understand the concept of unbiased processing, for example,  but this still tells me nothing about how it leads to authenticity, and by extension what authenticity is. How is it different than just being psychologically healthy, as measured by more specific traits?

Kaufman reviews the research on authenticity and show that really it’s just a rationalization for holding a favorably biased view of ourselves. People tend to think they are being authentic when they are acting on their virtues, being their best self, and also acting in ways that are congruent with societal expectations. The concept of authenticity is, in essence, used to manage one’s reputation. I am being authentic when doing things that other people will view positively, and not being my true self when I do things that will harm my reputation.

But as Kaufman points out – everything we do is a manifestation of some aspect of our true self. If you are acting in a way that is not congruent with your core values, you are still doing it for a reason that is part of your overall personality – that is part of your “true self.” If you are engaging in biased processing, or being insincere, these are part of who you are also – otherwise you wouldn’t be doing them.

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May 06 2019

Detecting Lies in the Brain

Published by under Neuroscience

It’s fairly common knowledge at this point that the polygraph test for detecting who is lying is not reliable enough to be used practically. Here is a good summary by the American Psychological Association (APA). The bottom line is that the entire idea of a lie-detector is problematic for various reasons. First, the underlying premises have not really emerged from psychological research, and has not been validated by research. The idea is that people will display physiological signs of stress when they are making an effort to be deceptive, or when confronted with incriminating information. However, the relationship between physiological signs and mental stress is too complex to develop any test. There is no universal feature of lying that can be detected.

The polygraph uses two basic techniques. The first is the control question test (CQT) – you ask questions of the person being examined, control questions that do not relate to the crime in question, and relevant questions related to the crime. The idea is that they will react more to the relevant than the control questions. The other method, the guilty knowledge test (GKT) is similar – mentioning random items along with one directly related to the crime may reveal guilty knowledge that only the perpetrator should know.

The idea sounds compelling, and it does work in that using these techniques results in a slight statistical advantage in determining who is lying and who isn’t. However, a small statistical advantage is all but worthless in practical application. There are too many false positives and false negatives to be useful. For any individual suspect, at the end of the test you still don’t know if they are lying or not.

Part of the problem is that people are complex and variable. Not everyone responds the same way to stress, or to the situations provoked in the testing. But the problem is worsened by the existence of effective mental countermeasures. There are two basic countermeasures that have been shown to be effective – lowering further the statistical effect of the polygraph. The first is to assign mental significance to control items or questions, thereby reacting similarly to the control and the relevant items. The second is to create mental distance to all the items, including the relevant ones. Focus on something else – the sound of the words, their precise dictionary meaning, or imagine a famous character saying them. If the statements are in writing, you can focus on the color of the ink, the font, or other superficial aspects.

These countermeasure work. They successfully blur any difference between control and relevant items.

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Apr 22 2019

Partially Reviving Dead Pig Brains

I turns out they were only “mostly dead.” Well, it depends on your definition of death.

This is an interesting study that has been widely reported, with a surprisingly small amount of hype. The New York Times writes:

‘Partly Alive’: Scientists Revive Cells in Brains From Dead Pigs
In a study that upends assumptions about brain death, researchers brought some cells back to life — or something like it.

All the reporting I have seen so far has appropriate caveats, but they are really trying hard to maximize the sensational aspects of this study. I actually wrote about this study one year ago when the data was first presented. Now it has been published, so there is another round of reporting (which interestingly ignores the prior reporting).

The quick version is that Yale neuroscientists collected decapitated pig brains four hours after death and then tried to keep the brain cells alive in order to see what would happen. It’s actually a great real-life Frankenstein type experiment, a fact not missed by some outlets. Here is what they did: Continue Reading »

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Apr 08 2019

More Research into Bullshit

Published by under Neuroscience

Often times when I state that I do not accept a claim at face value, I am challenged with the question – “Well, do you think they are lying?” The question results from a false dichotomy – that someone is either telling the truth or consciously lying. It misses a phenomenon that is perhaps vastly more large than conscious lying – bullshit.

Lying is when you say something that you know to be false. Bullshitting is when you say something that you don’t know is true or not. There is a spectrum here also, where people may be exaggerating or stretching what they know to be true, mixing in speculation and opinion with facts, distorting what is known with a conscious or unconscious agenda (motivated reasoning), or they are simply gullible themselves. How carefully do you vet a specific piece of information before you accept it and repeat it as true, and how transparent are you about your sources and your confidence in the information?

Most people, I would argue, are not careful enough. Being skeptical is essentially about being really careful and transparent about the information you accept.

Psychological researchers are trying to understand the phenomenon of bullshit, and actually use that term in the literature. A recent study extends this a bit, and is in line with previous research. Pennycook and Rand looked at 1,606 participants through online surveys. They evaluated how receptive they are to statements which are referred to as “pseudoprofound bullshit” and also their ability to discriminate real news from fake new.

Pseudoprofound bullshit are statements that are designed to superficially sound deep, but are actually utterly meaningless (think of pretty much anything Deepak Chopra says). For example, “Hidden meaning transforms unparalleled abstract beauty.”

There is even a website that generates random “Chopraesque” statements. For example, it just generated for me, “Innocence gives rise to subjective chaos.” This literally just uses an algorithm to string together random words but structured in such a way as to produce such statements.

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Apr 05 2019

The Color of Vowels

Published by under Neuroscience

What is the color, if you had to choose, of the “oo” sound in “boot”? What about the “ay” sound in “say”?

Researchers asked 1,000 participants this question, 200 of which have synesthesia – a condition in which different sensory and cognitive modalities blend into each other. Interestingly, 70% of non-synesthetes still had a structured answer to these questions. They had a mental map of what vowel sounds had which colors.

Synesthesia is a fascinating phenomenon, that is also a good reminder that our brains are just squishy machines, and they have quirky flaws like all machines. Brain function is mostly a result of networks of neurons firing together. There are various biological mechanisms that control the firing of neurons, so that they participate in networks but these electrical signals do not spread randomly through the brain (that’s basically what a seizure is).

These networks are horrifically complex, and interact with each other is complex ways to create neurological function. There are all sorts of variations of this brain wiring that can produce all the variation we see in people, including some that we would consider disorders or pathological.

Synesthesia is more of a condition than a disorder because it does not necessarily cause any demonstrable harm, and may even be an advantage in certain ways. Synesthetes have their brain networks crosses in unusual ways, so that they smell sound, see odors, or hear colors. They may also assign sensations to abstract concepts. Numbers may have a color, texture, or contour, for example. This is not imagination – they really perceive these things.

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Mar 12 2019

Robots Learning to Walk

Researchers at the USC Viterbi School of Engineering have developed a robotic limb with artificially intelligent control that learns how to walk by trying to walk. This may seem like a small thing, but it represents a fascinating trend in AI and robotics – shifting more and more to a bottom up rather than top down approach to programming.

This recent advance is very incremental, but worth pointing out. The researchers tried to designs a limb based on biological principles. Rather than programming the limb with the processes necessary to walk, including dealing with difficult terrain and recovering from a trip, they developed an algorithm that will learn how to walk and adapt by trying to do it. This type of learning algorithm from scratch is nothing new, but the researchers claim this is the first time it was applied to this particular task.

The results were impressive – the robot was able to learn how to walk within minutes. Because the learning is mostly trial and error, different iterations of this algorithm will hit upon different solutions, so different robots might have distinctive gaits.

The first thing I thought of when I read this news item is – what about Boston Dynamic’s Big Dog? This is a four-legged robot about the size of a large dog developed as a pack mule for the military, and capable of handling rough terrain. Watch the video – it’s impressive. I tried to find out how much of the Big Dog walking algorithm is learned vs programmed, but what I found is that “it’s proprietary.” But the consensus of opinion seems to be that it is partly both, a lot of developed walking algorithms but maybe incorporating some learning AI. If true the USC robotic limb would be the first fully self-learning walking robot algorithm, as they claim.

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