Archive for the 'Neuroscience' Category

Oct 20 2020

Daryl Bem, Psi Research, and Fixing Science

In 2011 Daryl Bem published a series of ten studies which he claimed demonstrated psi phenomena – that people could “feel the future”. He took standard psychological study methods and simply reversed the order of events, so that the effect was measured prior to the stimulus. Bem claimed to find significant results – therefore psi is real. Skeptics and psychologists were not impressed, for various reasons. At the time, I wrote this:

Perhaps the best thing to come out of Bem’s research is an editorial to be printed with the studies – Why Psychologists Must Change the Way They Analyze Their Data: The Case of Psi by Eric Jan Wagenmakers, Ruud Wetzels, Denny Borsboom, & Han van der Maas from the University of Amsterdam. I urge you to read this paper in its entirety, and I am definitely adding this to my filing cabinet of seminal papers. They hit the nail absolutely on the head with their analysis.

Their primary point is this – when research finds positive results for an apparently impossible phenomenon, this is probably not telling us something new about the universe, but rather is probably telling us something very important about the limitations of our research methods

I interviewed Wagenmakers for the SGU, and he added some juicy tidbits. For example, Bem had previously authored a chapter in a textbook on research methodology in which he essentially advocated for p-hacking. This refers to a set of bad research methods that gives the researchers enough wiggle room to fudge the results, enough to make negative data seem statistically significant. This could be as seemingly innocent as deciding when to stop collecting data after you have already peeked at some of the results.

Richard Wiseman, who was one of the first psychologists to try to replicate Bem’s research and came up with negative results, recently published a paper discussing this very issue. In his blog post about the article he credits Bem’s research with being a significant motivator for improving research rigor in psychology:

Several researchers noted that the criticisms aimed at Bem’s work also applied to many studies from mainstream psychology. Many of the problems surrounded researchers changing their statistics and hypotheses after they had looked at their data, and so commentators urged researchers to submit a detailed description of their plans prior to running their studies. In 2013, psychologist Chris Chambers played a key role in getting the academic journal Cortex to adopt the procedure (known as a Registered Report), and many other journals quickly followed suit.

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Oct 12 2020

Pre-Bunking

Psychologists in the UK have created a game that pre-debunks (or “pre-bunks”) COVID-19 conspiracy theories. The game is based on research that shows it can be more effective to give people information about how to identify conspiracy theories or misinformation before they are exposed to it. This is a fantastic idea, and I love the fact that this is being done in coordination with research to show if it is effective.

The current game is called Go Viral. It puts the player in the role of someone spreading conspiracy theories about the pandemic, and their goal is to make the misinformation go as viral as possible. This way the players learn the deceptive tactics of those who spread such misinformation by doing it themselves. This tactic reminds me of magicians who are skeptics. They have learned the techniques of deception, and have experienced how easy it can be to deceive people. Stage magic is essentially the practical art of misdirection, that exploits many of the weaknesses in our ability to perceive and construct an experience of what is happening. This puts magicians into a perfect position to detect deceptive practices on the part of others.

James Randi, for example, made a career out of exactly this. He has caught faith healers, for example, using standard mentalist tricks to deceive their audience. One example is the one-ahead trick. You have everyone fill out a “prayer card” with their basic information and what they want to pray for. All these cards are placed in envelopes and are then placed in a bowl, and the preacher draws them one by one “predicting” what each one will say prior to opening the envelope and “revealing” that they were correct. The audience is flabbergasted as the preacher, by seemingly divine means, knows all about them. However, the preacher is simply stating what they just read on the previous card. If you are a magician, this technique is easy to detect – and now you can detect it much easier because I just told you about it.

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Sep 08 2020

QAnon and Other Conspiracies

I previously wrote that the flat Earth movement is the mother of all conspiracies – it essentially is the ultimate conspiracy in that, if you believe that the world is actually flat then you also have to believe that there has been a massive conspiracy involving millions of people all of the world over centuries. If “they” can lie to us about the shape of the world, then they can lie to us about anything. Once you have been convinced that the spherical nature of the Earth is a grand conspiracy, then you can believe anything. Facts, expertise, authority all cease to exist. And that, I think, is the point. That is the appeal of flat Eartherism – it gives you permission to believe anything you want, to reject any claim, any fact, out of hand. You have the freedom to construct reality the way you wish, and can dispense with the tedious part of having to deal with actual reality.

Recently another conspiracy has been getting more attention, and may have eclipsed the flat Earth theory as the most extreme conspiracy. This one is more of a politically-based rather than science-based conspiracy, but that is not as critical as you might think. Phenomenologically they are the same, and the subject matter is actually secondary. But in any case, the Q conspiracy holds that Hillary Clinton and other prominent Democrats are part of a world-wide cabal of Satan-worshiping cannibalistic pedophiles who are trying to secretly take over the world. Further, Trump is actually secretly a genius who is working behind the scenes, with Mueller and in some incarnations with JFK Jr. who is secretly still alive, to uncover this cabal and bring them to justice (an event they call the “Storm”), and when he does he will usher in a golden age.

As with the flat Earth, the first reaction someone might have to hearing these conspiracies is that they are incredibly dumb. They are epically stupid, in a childish way. That may be true, but if you stop there then you miss what is actually going on. Also, it is very tempting to conclude that because the conspiracy theories themselves are mindbogglingly ridiculous, that people who believe them must be themselves “epically stupid”. But I don’t think that’s true, and that conclusion misses the actual phenomenon at work.

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Aug 31 2020

Elon Musk Unveils Neuralink Pig

Three days ago Elon Musk revealed an update to his Neuralink project – a pig named Gertrude that had the latest version of the Neuralink implanted. (I first wrote about the Neuralink here.) The demonstration does not seem to involve anything that itself is new with brain-machine interfaces, but it does represent Musk bringing the state of the art together into a device that is designed to be commercial, rather than just a laboratory proof-of-concept.

Unfortunately, I have had to cobble together information from multiple sources. There does not appear to be a scientific paper with all the technical details spelled out, and the mainstream reporting is often vague on those details. But I think I have a clear picture now. The device is a coin-sized, 23 mm diameter and 8 mm thick. It was implanted “in” the skull, and also described as being “flush” with the skull. From this I take it that the device is not on top of or inside the skull, but literally replacing a small piece of skull. It has 3,000 super thin and flexible electrodes that connect to 1000 neurons. The device itself has 1024 channels (a channel reads the electrical difference between two electrodes).

The company also reports that it has an internal battery that can last “all day” and then recharge overnight. It also communicates to an external device (such as an app on your smartphone) via bluetooth with a range of 5-10 meters. As an electronic device, this is pretty standard, but it is good to have these features in a small implantable device.

The big question is – what can the Neuralink actually do? The demonstration, in this regard, was not that impressive (compared to the hype for Neuralink) – just the absolute bare minimum for such a device. It was implanted in a pig and was interfaced with neurons that connect to the snout. This demo device was read only; it could not send signals to the pig’s brain, only read from the brain. The demonstration consisted of Gertrude sniffing around her cage, and when she did so we could see signals from the neurons in her brain that were interfacing with the Neuralink.

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Aug 17 2020

Adding Sound to AI

It has been fascinating, perhaps especially so as a neuroscientist, to watch the progress being made in artificial intelligence (AI), robotics, and brain-machine interface. Our understanding of biological intelligence is progressing in tandem with our attempts to replicate some of the functioning of that intelligence, as well as interface with it. Neuroscience and AI/robotics inform each other.

Here is another example of that – adding sound to the perception of an AI/robotic system to help it distinguish different objects. Before now AI object recognition has mostly been purely visual. (I always qualify these statements because I am not aware of every lab in the world that might be working on such things.) Visual object recognition is a good place to start, and this is what we probably think of when we imagine identifying an object ourselves – we look at it and compare it to our mental database of known objects. That is how our visual processing works.

But that is also not the whole story. We tend to underestimate, or simply not be aware of, the extent to which our brain are simultaneously processing multiple different sensory modalities to make sense of the world. When we listen to someone talk, for example, our brains also process the movement of their lips in order to make sense of the sounds as language (this is called the McGurk effect). When we identify someone else’s probable gender, we are strongly influenced by their voice.

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Aug 07 2020

Liver Fairies

Published by under Neuroscience

Liver scientists have a hypothesis – that the biological functioning of the liver, from the organism level down to the cellular level – is actually responsible for all the functions that appear to correlate with the liver. This is not a controversial hypothesis.

If, for example, those with severe liver disease, such as cirrhosis, lose the ability to make certain clotting factors, to regulate their blood glucose, to produce bile and digest fats, to metabolize drugs, and detoxify the blood, and to eliminate certain metabolic products from the blood, such as bilirubin, then those are all things that the liver actually does. In other words, the reason for the correlation is that liver function is the ultimate biological causation of all these things. Other parts of the body may be involved, but the liver is in the loop somewhere.

This hypothesis holds up very well. Liver disease reliably correlates with these downstream effects, and curing the liver or replacing it in severe cases reverses these effects. We can also culture liver cells in the lab and measure many aspects of their biological function, such as producing enzymes and metabolizing drugs. In many cases we have identified genes for liver enzymes, and can see that they are active in liver cells and not active in non-liver cells (mostly, there are always layers of complexity). We can even identify in some cases genetic mutations that produce altered function of those enzymes and produce specific diseases.

In fact the scientific hypothesis that the biological activity of the liver causes everything we see as liver function is so well established that it is taken as a given, and not questioned by any serious scientist. Over decades, countless labs and researchers doing countless studies have all relied upon this assumption, and it has worked out well.

This all may seem so obvious that it is silly to bother to point it out. But what if there were those who claimed that, in actual fact, some of what we think of as liver function is actually a manifestation of liver fairies. These are mystical entities that live in the liver. They are invisible and undetectable, but they carry out some of the functions we think of as liver function. The only reason that these functions correlate with the liver is because that is where the liver fairies live. They become unhappy when their home is not healthy, and stop doing some of their functions.

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Jul 20 2020

Mistaking Intention for Behavior

Published by under Neuroscience

Here’s another brain glitch that I know I do on a regular basis – confusing the intention to do a task with having actually completed the task. This is a type of false memory created by the intention itself. Albarracin et al have published a series of five experiments where they explore this phenomenon, which they claim is new to the published literature.

In there experiments people reported having completed a task that they only thought about doing but never actually did. If the task is routine this is more likely to happen. For example, if you take medication every day, you might remember taking the medication when you didn’t partly because you already have so many memories of actually taking the medication. Just having the thought – I need to take my medication – may be enough to trigger a false memory of taking it when you later think back about whether or not you took the medication. The experiments show that forming the intention to do the task increases the likelihood of forming such false memories.

The situation is also a factor. The closer the intention is to the actual task, the more likely it is you will form such a false memory of task completion. In other words, if you are sitting at your desk and you make a mental note that you have to do some task at your desk (such as sending an e-mail or signing a form), you may later remember having completed the task. This is more likely to occur than if the task involved traveling to a new location. They report:

Participants chose job candidates and either acted on the decision to hire them, generated an intention to hire them later or made a judgment that was irrelevant to the behavior.

Following a delay, participants were asked to report whether they had acted on the decision or simply intended to do so for each person they had seen.

“The methodology was carefully crafted to produce the necessary high level of errors we were studying, to keep irrelevant characteristics constant across conditions, and to systematically manipulate enactment versus intention,” said Albarracin, also a professor of business administration at Illinois. “If intentions play a causal role in producing misreports of behavior, misreports should be more common in the intention than the control condition.”

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Jul 14 2020

Imagining vs Seeing

Published by under Neuroscience

Try to conjure up a mental image of a bicycle (without referencing a picture). Better yet, try to draw a bicycle. Most people (75% or more) cannot draw an accurate bicycle from memory. There are a lot of layers here. First, people tend to grossly overestimate their specific or technical knowledge, especially of everyday objects and processes. I often like to challenge myself with the caveman thought experiment. If I suddenly found myself 20,000 years in the past living with pretechnological humans, how much technology could I bootstrap from my own knowledge? The answer is – surprisingly little (unless you are an expert in such things).

There is also the fact that we tend to overestimate the detailed accuracy of our memories. How many times have you seen a bike, and yet you cannot conjure up an accurate image of one in your brain. Perception itself is also limited – we tend to see what we pay attention to, and perception is highly filtered through our memory and expectation. I experienced this first hand when I started birding. Birds I had lived with my entire life suddenly became visible to me.

There is also the layer of – what is the neurological difference between imagining and seeing? Neuroscientists have already demonstrated that when we imagine or remember an image we use the same visual cortex as when we actually see an image. This makes sense because the visual cortex is organized in order to represent visual images, whether we are seeing, remembering, or imagining those images. In fact, there is probably little to no difference between remembering and imagining, but that is a topic for another day. What I want to explore further is a recent study that looked at the difference between seeing and imagining.

The researchers addressed this question in two ways. First they used a neural network designed to create and process images, and further designed to mimic the functional organization of the human brain. Specifically the neural network had basic or primary visual processing, and then more higher level visual processing. The researchers found that when creating an image the system activated the primary visual processing more diffusely but in less detail then when “seeing” an image. The researchers used this as a prediction and then studies human brains with fMRI to see if the computer model predicted human brain activity.

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Jul 09 2020

The Brain’s Filter

Published by under Neuroscience

If you have not seen this video of students passing basketballs around, watch it now before reading further.

The now famous video, from Simons 1999, is a demonstration of inattentional blindness. There is no trick here, just a demonstration of normal brain functioning. When we are focusing our attention on one type of stimuli we can filter out “distracting” stimuli that doesn’t fit the parameters. In the basketball example you were instructed to pay attention to the students in white, so your brain flagged the students in black as distracting information. The gorilla, which is also black, was therefore filtered out as well (for about 40% of subjects).

Interestingly, often people take pride in having noticed the gorilla, but this is not necessarily a manifestation of having better attention. In fact noticing the gorilla, if anything, might mean you are more distractable and have worse attention (it also can be mostly random chance). The brain is supposed to filter out extraneous stimulation, otherwise we would not be able to function. Those suffering from traumatic brain injury, for example, often complain that they cannot filter out distracting sensory stimuli, so they find noisy or busy environments (like crowds) very uncomfortable. They may not be able to focus on work unless they are in a distraction-free environment. It’s impairing.

In other words – in the experimental setup of the students passing around the basketballs, not noticing the gorilla was an active step of filtration by the brain, not a failure to notice the gorilla. Such inattentional blindness is now experimentally well-established. Actually (interesting story) the first experiments demonstrating inattentional blindness were in 1959, but they were accidental. Paranormal researcher Tony Cornell published a couple of experiments regarding people noticing a subject wearing a ghost costume, and found that surprisingly few people did. He interpreted the results incorrectly, as evidence that a person in a sheet lacked the psi phenomena of a “real” ghost, but now we can look back and clearly see inattentional blindness at work.

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Jun 04 2020

fMRI Researcher Questions fMRI Research

Published by under Neuroscience

This is an important and sobering study, that I fear will not get a lot of press attention – especially in the context of current events. It is a bit wonky, but this is exactly the level of knowledge one needs in order to be able to have any chance of consuming and putting into context scientific research.

I have discussed fMRI previously – it stands for functional magnetic resonance imaging. It uses MRI technology to image blood flow to different parts of the brain, and from that infer brain activity. It is used more in research than clinically, but it does have some clinical application – if, for example, we want to see how active a lesion in the brain is. In research it is used to help map the brain, to image how different parts of the brain network and function together. It is also used to see which part of the brain lights up when subjects engage in specific tasks. It is this last application of fMRI that was studied.

Professor Ahmad Hariri from Duke University just published a reanalysis of the last 15 years of his own research, calling into question its validity. Any time someone points out that an entire field of research might have some fatal problems, it is reason for concern. But I do have to point out the obvious silver lining here – this is the power of science, self-correction. This is a dramatic example, with a researcher questioning his own research, and not afraid to publish a study which might wipe out the last 15 years of his own research.

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