Archive for the 'Neuroscience' Category

Sep 14 2021

Cognitive Control and Cheating

Published by under Neuroscience

It is a fundamental truth of human behavior that people sometimes cheat. And yet, we tend to have strong moral judgements against cheating, which leads to anti-cheating social pressure. How does this all play out in the human brain?

Psychologists have tried to understand this within the standard neuroscience paradigm – that people have basic motivations mostly designed to meet fundamental needs, but we also have higher executive function that can strategically override these motivations. So the desire to cheat in order to secure some gain is countered by moral self-control, leading to an internal conflict (cognitive dissonance). We can resolve the dissonance in a number of ways. We can rationalize the morality in order to internally justify the desire to cheat, or we can suppress the desire to cheat and get a reward by feeling good about ourselves. Except experimentally most people do not fall at either end of the spectrum, but rather they cheat sometimes.

Recent research, however, has challenged this narrative, that cheating for gain is the default behavior and not cheating requires cognitive control. A new study replicates prior research showing that people differ in terms of their default behavior. Some people are mostly honest and only cheat a little, while others mostly cheat, and there is a continuum between. Perhaps even more interesting is that the research suggests that for those who at baseline tend to cheat, markers of cognitive control (using an EEG to measure brain activity) increase when they don’t cheat and behave honestly. That’s actually not the surprising part, and fits the classic narrative that people tend to cheat unless they exert self-control to be honest. However, those who are more honest at baseline show the same markers of increased cognitive control when they do cheat. They have to override their inherent instinct in the same way that baseline cheaters do. What’s happening here?

Before I discuss how to interpret all this, let me explain the research paradigm. Subjects were tasked with finding differences between two similar images. If they could find three differences, they were given a real reward. However, some of the images only had two differences, so subjects had to either accept defeat or cheat in order to win. First subjects were tested at baseline to determine their inherent tendency to cheat. Then they were encouraged to cheat with the rigged games. EEGs were used to measure theta wave activity in specific parts of the brain, which correlates with the degree of cognitive control. Subjects who cheated more at baseline showed increased theta activity when they didn’t cheat, and those who were more honest at baseline showed increased theta activity when they cheated.

Therefore, it appears more accurate to say that cognitive control allows us not to do the morally “correct” thing, but to act against our instincts, whatever they are. But why would people have such different instincts in the first place?

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Sep 02 2021

Bionic Arms

The term “bionics” was coined by Jack E. Steele in August 1958. It is a portmanteau of biologic and electronic. Martin Caidin used the word in his 1972 novel, Cyborg (which is another portmanteau of cybernetic organism). But the term really became popularized in the 1970s TV show, The Six Million Dollar Man. Of course, at the time bionic limbs seemed futuristic, perhaps something we would see in a few decades. Thirty years always feels like far enough in the future that any imagined technology should be ready by then. But here we are, almost 50 years later, and we are nowhere near the technology Steve Austin was sporting. Bionics, as depicted, was more like 100 or more years premature. This is tech more appropriate to Luke Skywalker’s hand in Star Wars, rather than some secret government project in the 1970s.

We are, however, making progress, which I have been writing about periodically here. Now a team at Cleveland Clinic has produced a robot arm tested in two subjects, and they are breaking out the term “bionic” to describe their technology. They achieve their level of functionality by combining three aspects of a brain-machine interface connecting to a robotic limb – intuitive motor control, touch sensation, and kinesthetic sensation (simulating proprioception with vibration). The kinesthetic sensation allows the user to feel the robotic limb’s movements. The authors write:

Here, we show that the neurorobotic fusion of touch, grip kinesthesia, and intuitive motor control promotes levels of behavioral performance that are stratified toward able-bodied function and away from standard-of-care prosthetic users.

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Jul 30 2021

Visual Persistence in a Dynamic World

Published by under Neuroscience

We mostly take our vision for granted. I am not referring to how much we appreciate having good vision, for those who do, but rather we tend to be unaware of how much of a neurological feat simple vision is. In a way, we evolved not to appreciate this – the experience of good vision evolved to be seamless, and to hide all the massive processing necessary to make it so. Neuroscientists, however, have been making a lot of progress reverse engineering how our brains process vision, uncovering new layers of complexity.

A recent study, for example, looked at the persistence of visual images in the brain given dynamic stimuli. How does the brain maintain a constant representation of an object in the world when the image of that object might be dramatically and rapidly changing? Again, we tend to think of our own vision like a video camera, passively recording what is out there. But actually vision is a complex hierarchical constructive process. Imagine, for example, driving in a car. There are other cars on the road, and there are objects on the side of the road you are passing by. The visual image falling on your retina is changing dynamically, and your brain has to keep up with all this change while maintaining a sense of stability.

How much processing power this takes becomes apparent to many people with traumatic brain injury (TBI). This can cause a disrupti0n in the connections among neurons of the brain, slowing down processing speed. People with TBI often experience disorientation when driving, moving quickly, or even turning around. Their brain cannot keep up with the rapidly changing visual input. This is a common symptom because visual processing is one of the most intense that happens in the brain, so it is the first to be affected (the ability to focus and shift attention being another).

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Jul 27 2021

Treating Brain Cancer with Magnets

Magnets for healing have a bad rap, one they rightfully deserve. Magnetic snake-oil devices with all sorts of bogus medical claims are as old as magnets themselves. It may have something to do with the fact that magnets seem like magic, exerting and invisible force at a distance. So it’s often an easy sell.¬†Also, magnets are real and do produce a real energy field (unlike the non-existent “life energy” fields common in alternative medicine). So it makes any claims for them seem all the more plausible.

Because of this, magnets do have real medical applications. Perhaps most common is MRI scans – magnetic resonance imaging. But also there is a lot of research into TMS, transcranial magnetic stimulation, for a variety of neurological indications. Our bodies are electromagnetic devices, and we can alter cell function with electricity and magnetic fields. The trick is, applying them in such a way that they can be exploited for benefit rather than causing harm or having no real effect.

For the consumer with insufficient scientific or medical background, it can be very challenging to tell the difference between a legitimate magnetic medical device and a scam. One good rule of thumb – if the magnet is fairly weak (refrigerator magnet level) it is probably worthless. Real biologically active magnets tend to be powerful. Another slightly more technical fact is that biologically active magnets tend to have an alternating field, while magnetic quack devices tend to have a static magnetic field (which has little biological effect).

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Jul 06 2021

The Grandmother Neuron

Published by under Neuroscience

People are really good at recognizing faces. One of my lecture bits is to show a picture of a famous person for a fraction of a second (as fast as I can make the picture cycle in Powerpoint). The vast majority of the audience has no problem placing this face in their memory from just a quick glance. How does the brain accomplish this feat? That is something that neuroscientists are still working out. We already have a lot of information about the visual cortex and how it puts images together. We also know that the fusiform gyrus is essential for facial recognition. This brain structure lies at the junction of the occipital lobe, where the visual cortex is, and the medial temporal lobe which is involved with memory.

What is not well understood is exactly how the visual cortex connects to memory – how do we recognize familiar faces? One hypothesis is somewhat dismissively known as “the grandmother neuron”, based on the idea that one neuron would encode the face of your grandmother and connect that pattern with your memories of your grandmother. No such neuron has been discovered, and advances in neuroscience have led to the conclusion that it likely never will be. One neuron is insufficient to encode something as complex as a human face.

But perhaps there is a region or a circuit or network in the brain that serves this function. Neuroscientists may have zeroed in on the brain region that functions like the grandmother neuron. They studied macaque monkeys, exposing them to pictures of faces they have seen in person and other they have not seen before except digitally. When pictures of faces they have seen before were displayed the temporal pole (front tip of the temporal lobes) lit up on fMRI scanning. This cluster of cells also responded “non linearly” when increasing amounts of a familiar faces were shown, implying that the whole pattern is greater than the sum of its parts. Further, when distinctive parts of a face were show they lit up as if the entire face were show. This could indicate that once sufficient detail were shown to trigger the memory of the entire face, full activity of that region was then engaged.

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Jun 22 2021

Brain Implant to Treat Pain

Published by under Neuroscience

Researchers report a study in which they investigate the potential of a closed loop brain-machine interface (BMI) to treat pain in rats. If this line of research is successful it could lead to a new paradigm in the management of chronic pain.

Chronic pain is a tricky condition to treat because we currently have limited options, all of which are problematic in some way. Acute pain, such as after trauma or surgery, is easier to manage because the treatment course is likely to be limited. This kind of pain is called nociceptive pain, when it is the result of tissue damage. The obvious goal here is to manage the damage by treating the underlying condition, but manage the pain in the meantime until healing can reduce the pain. Another category of pain is terminal pain, such as in some cancer patients. While this has its own challenges, aggressive pain management is also appropriate.

Chronic pain, however, may need to be sustained for years, and this presents serious challenges. This may be due to chronic conditions that cannot be cured, such as arthritis, degenerative changes, and primary pain conditions like migraines. This category also include neuropathic pain, where the pain is due to abnormalities in the nervous system itself, rather than the nervous system properly detecting tissue damage. With neuropathic pain, the pain itself is often the disorder.

The challenges of chronic pain stem from the fact that it is often difficult to find a treatment that is effective. But also, even if a treatment is effective, pain medication itself (analgesics) has risks from long term use. Aspirin-like drugs (NSAIDS) can cause ulcers and kidney damage. Acetaminophen can cause liver damage. Narcotics are addictive and cause tolerance. The best approach to chronic neuropathic pain is what we call neuropathic pain prophylaxis – medications safe and intended to take daily to reduce overall pain. But these medications can have significant side effects, and don’t always work sufficiently. There are also nerve stimulators, which avoid pharmaceutical side effects, but have limited efficacy.

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Jun 18 2021

How Predictable Are We?

Magicians, marketers, and politicians all count, to some degree, on the belief that people (at least collectively) behave in fairly predictable patterns. Each has their own subculture and, history, and research as a guide, but the core phenomenon is the same. Magicians are probably the easiest to demonstrate – if you have ever been to a quality magic show you have likely been amazed at what you saw. This is because magicians exploit predictable patterns in how people direct their attention and process information, knowledge built over centuries of trial and error. Politicians, rather, seem to go on personality and social instinct, with the good ones rising to the top. Although they are increasingly supported by a campaigning industry which is very data driven.

Political campaigns, therefore, are increasingly like any marketing campaign, which is intensively data and research driven. Not only do marketers read and benefit from the psychological research, they have their own research, complete with their own scientific journals. All of this is premised on the notion that people are far from the unique snowflakes we like to think, and are more like predictable sheep that can be herded. Research generally supports this latter view.

Now of course anyone can rise above the herd with knowledge, critical thinking, and consumer savvy. We can learn the tricks, read reviews, learn something about cognitive biases, and take more control of our own purchasing decisions. While I highly recommend all of this, the result is partly an arms-race where marketers try to get more and more subtle with their manipulation, trying to fly under our critical thinking radar. With the advent of big data, social media, and artificial intelligence (AI) their ability to do so is getting frighteningly powerful. This is not something we should underestimate.

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Jun 15 2021

Waking from Coma

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There are many amusing movie tropes, mostly used as a shorthand for directors to communicate with the audience. Bags of groceries always have either a loaf of bread or a leafy vegetable sticking out the top, so that you know at a glance they are groceries. Live mics always give a burst of feedback when someone steps up to them. Holograms always glitch, so you know they are holograms. People falling in love always spray water on each other and shop in open-air markets. All raptors sound like red-tailed hawks.

Some tropes, however, are not benign. They are based on and perpetuate a misunderstanding of reality. A pernicious one I have had to deal with professionally is the motion that someone can wake from a prolonged coma and suddenly be neurologically high functioning. They wake up, they are bleary eyed and confused but otherwise intact. As an aside, another trope is that as soon as the person wakes up whoever is present yells for a doctor as if it is an emergency. Here’s a pro tip – it might be an emergency when someone suddenly falls unconscious, but not when they wake up.

Typically there may be a period of physical recovery so they can get their strength back, but neurologically waking up from a coma is presented as flipping on a switch. The problem with this trope is that it almost never occurs (and I am saying “almost” just to be cautious – I am not aware of any cases). This does not mean that meaningful recovery cannot happen, but we have to put this into perspective. The trope also goes beyond entertainment. We see it in news reporting as well, even if only by glossing over important details. Here is a recent BBC report of a woman waking from a 10 month coma. A non-expert reading this would almost certainly come away with a distorted impression of what likely happened (I have no inside information on this specific case, I am only basing that assessment on the BBC report).

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Jun 10 2021

Brain Connections in Aphantasia

There is definitely something to be said for the neurodiversity perspective – when it comes to brain function there is a wide range of what can be considered healthy. Not all differences should be looked at through the lens of pathology or dysfunction. Some brains may be more typical than others, but that does not mean objectively “normal”, better, or healthier. Like any valid concept it can be taken too far. There are conditions that can reasonably considered to be brain disorders causing objective dysfunction. But the scope of healthy variation is likely far broader than many people assume.

Part of this concept is that brain organization and function includes many trade-0ffs. To some extent this is a simple matter of finite brain resources that are allocated to specific abilities, increase one and by necessity another has to diminish. Also different functions can be at cross-purposes. Extraverts may excel in social situations, but introverts are better able to focus their attention inward to accomplish certain tasks.

In light of this, how should we view the phenomenon of aphantasia, a relative inability to summon a mental image? Like most neurological functions, the ability to have an internal mental image varies along a spectrum. At one end of the extreme are those with a hyperability to recall detailed mental images. At the other are those who may completely lack this ability. Most people are lumped somewhere in the middle. The phenomenon of aphantasia was first described in the 1880s, then mostly forgotten for about a century, and now there is renewed interest partly due to our increased ability to image brain function.

A new study does just that, looking at people across that phantasia spectrum to see how their brain’s differ. Using fMRI they scanned the brains of those with aphantasia, hyperphantasia, and average ability. They found that in neurotypical subject there was a robust connection between the visual cortex (which becomes active when imagining an image) and the frontal cortex, involved in attention and decision-making. That makes sense – this connection allows us to direct our attention inwardly to our visual cortex, to activate specific stored images there. Subjects with aphantasia had a relative lack of these connections. While this is a simple model, it makes perfect sense.

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Jun 04 2021

How Common Are BS Jobs?

Published by under Neuroscience

Douglas Adams had a talent for irony. In the Hitchhiker’s Guide series he told the tale of a civilization that tried to improve itself by tricking everyone with a useless job into taking a rocket trip to another world (actually to nowhere). For example, one of the discarded people’s jobs was to clean phones. That’s it – they were a phone cleaner. That civilization later collapsed due to a pandemic started by a phone virus.

Part of Adams’ humor was taking reality and then pushing it to the absurd, but that core of reality gave his humor more heft. We may not have phone cleaners, but it does seem that certain jobs are less useful than others. Of course there is a certain amount of subjectivity and value judgements here, but there are some jobs that even the people in them judge to be without purpose. The concept of “bullshit jobs” was proposed by anthropologist David Graeber. In his book Bullshit Jobs, he claims that 20-50% of people are in BS jobs, that this number is increasing over time, that BS jobs are concentrated in certain professions, and that such jobs are psychologically unhealthy. New research finds that he was correct in one out of four of these claims.

While Graeber was bringing attention to a real issue, the psychological effects of being in a job that you yourself feel is of no value, when it came to the magnitude of this issue he did not have hard data. He was largely making inferences. This did lead to mixed reviews of his work at the time, with some reviewers finding his arguments often labored. The new research is an extensive survey of workers in Europe between 2005-2015, with over 30,000 responses. Since by his own definition, a BS job is one that even the person in it feels is worthless, the survey relied upon self-report of whether one’s job had value. Those who responded “rarely or never” to the question, “I have the feeling of doing useful work,” were deemed to have a BS job. The total percentage of people in this category was 4.8%. That’s still about one in 20 people, but a far cry from the as high as 50% Graeber claimed.

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