Archive for the 'Neuroscience' Category

Mar 30 2018

Social Jet Lag

Published by under Neuroscience

Sleep is critical for optimum health and performance, but is often underappreciated by the general public. For example, I see many patients with chronic symptoms that are either caused by or greatly exacerbated by poor sleep, but didn’t make the connection to their chronic insomnia.

Not only is adequate quality sleep necessary, people have different daily (“circadian”) rhythms – some people are most alert in the morning, others mid-day, and still others in the evening. Further, this does not seem to be due entirely to habits, and therefore we cannot just tell night owls to go to bed earlier. They are not in control of their biological rhythm.

The sleep rhythm is affected by light levels and seasonal differences, so there is some room for tweaking the environment to improve sleep overall and adjust the daily cycle. Bright lights and close-up electronic devices are terrible for sleep in the late evening. If someone is having trouble getting to sleep, having 2 hours or so without electronic devices prior to bed time is a good idea.  But there are limits here as well – night owls will still be night owls.

A recent study looks at the effect of circadian rhythm on school performance. The hypothesis was that a mismatch between a student’s internal schedule and their forced school schedule would affect performance.

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Mar 27 2018

Wearable Magnetoencephalography

There are scientific advances, and then there are advances that help us make more scientific advances. The latter are often trickier to communicate to the public, because their connection to any tangible benefit is indirect. But improvements in research technology itself can have incredible potential to transform our future.

One category of scientific instruments that I am particularly interested in, as a neuroscientist, are ways to scan the brain, both anatomically and functionally. A functional scan is one that looks at how the brain is functioning in real time, it looks at the pattern of activity of brain cells. If we can correlate this brain activity with specific tasks, then that will teach us something about how the brain works.

Using this type of technology scientists are trying to reverse-engineer the brain, to map all of its connections (the connectome) and learn what the brain’s networks actually do. The ultimate goal is to be able to simulate those networks in a computer, or to build a computer that works like the brain. That would be the ultimate brain research tool – then you could run countless simulations and tests and see how the various networks in the brain behave.

As an aside, it’s likely that even a simulated brain, if it were functioning, would be self-aware. That raises a lot of ethical question in terms of further research.

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Mar 12 2018

The Brain and Predictive Coding

Published by under Neuroscience

One way to learn about how a system functions is to examine how it fails. Historically much of our knowledge of the most complex system we know, the nervous system, derived from examining patients with neurological deficits and then examining their brain (prior to imaging, this meant at autopsy).

This process is particularly fascinating with the human brain because we don’t yet know all of the things that the brain does. Some brain functions are obvious, like vision or motor control, because they are conscious. But most of what the brain does is subconscious, and we have had to specifically learn that the brain even needs to do certain things, mostly by examining what happens when the brain fails to do those things.

For example, we take for granted that we move as much as we desire to more, no more or less. But this balance between desire to move and the resulting movement is not automatic. There is an entire system within the brain, the extrapyramidal system, that is a series of feedback loops that carefully modulate moment to moment the gain of voluntary movement (the relationship between input – desire to move, and output – movement). Parkinson’s disease results from a disruption in this circuit which causes the gain to be turned down, so people move less and can even freeze. Chorea (as in Huntington’s chorea) involves the gain being turned up, so people with this disease are constantly writhing.

There are many other amazing examples of things most people are not aware that their brains do, or even that they have to do them. There are circuits in the brain necessary for feeling that you occupy your body, that you own and control your various body parts, and that you are separate from the universe. Disrupt these circuits, and your reality changes.

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Mar 02 2018

Déjà vu and Familiarity

Published by under Neuroscience

Most people have had the common experience of feeling as if we have been someplace before, or that events that are occurring in real time have happened before. Sometimes we feel as if we know what is going to happen next – and then it happens. Unsurprisingly some have interpreted these phenomena as evidence for some type of extrasensory perception. Something weird certainly seems to be going on.

Neuroscientists have been extremely successful in at least partially explaining many such weird experiences. What is uncanny is that our experience of reality is a constructed illusion, and occasionally we experience the glitches in this construction. The most obvious examples of this are optical illusions. We marvel at how our visual construction can be deceived, or can flip between different states.

But everything, not just vision, is a similarly artificial neurological construction subject to illusory effects. That includes memory.

That déjà vu is a memory glitch is old news. But neuroscientists have been teasing apart the phenomenon in more detail, revealing some aspects of how our memories work. A recent study adds another bit of information to our understanding, which we can use as a jumping off point to review what we know.

Anne Cleary, a cognitive psychologist at Colorado State University, has been researching déjà vu and related phenomena. She believes that déjà vu is a manifestation of a memory phenomenon known as familiarity.

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Feb 26 2018

The Efficacy of Antidepressants

A new major study finds that antidepressants are effective for the acute treatment of major depression. The study is considered a definitive systematic review and meta-analysis including 522 trials comprising 116,477 participants. This includes unpublished data from pharmaceutical companies, to address the concern that some negative data was being hidden.

In the study all 21 antidepressants studied were more effective than placebo, ranging from 1.37 times as effective to 2.13 times as effective.

This is not surprising to anyone familiar with the evidence – it is, in fact, just a review of that evidence. However, many in the public might be confused because these results seem to contradict previously reported studies that purport to show that for many patient antidepressants are no more effective than placebo.

This confusion, however, is largely due to poor reporting. The key factor that is often missed is the severity of the depression. Often I hear people claim that, “Antidepressants have been shown not to work for depression.” But that is not a meaningful statement because you cannot scientifically refer to the evidence regarding “depression” without qualifying “mild to moderate” vs “severe” depression. That detail often gets dropped in mainstream reporting, and therefore the public consciousness.

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Feb 19 2018

Brain Plasticity in Infants

Published by under Neuroscience

A new study looks at the brains of young adults who suffered a stroke in the language center of their brains as infants. They found that the subjects developed normal language, which just relocated to the mirror-image other side of the brain. This is not surprising, and reflects our evolving understanding of how the brain develops and functions.

For most people language localizes to the left frontal and temporal lobes of the brain. Broca’s area in the frontal lobe is involved in speaking, in the subtle motor output necessary to precisely articulate words. Wernicke’s area is in the temporal lobe and is involved in translating words into ideas and ideas into words. The two areas are connected by the arcuate fasciculous. These are the central language areas. There is also surrounding cortex which is necessary for communication between the language structures and other parts of the brain.

For most people the language area is on the left side of the brain. Meanwhile, the mirror right side of the brain is involved with understanding and producing speech intonation – knowing when someone is asking a question or being sarcastic. The right side is also involved with music and singing.

We also know that brains are plastic, meaning they can change the structure of their connections as necessary. People often use a computer analogy when talking about the brain, but the analogy to digital computers is flawed. Computers are hardware that run software, but brains are neither hardware or software – they are wetware, which is both at the same time. The connection of neurons in the brain is where information is stored and processed, and those connections change as a result of the processing, which alters the memory.

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Feb 15 2018

The Neuroscience of Virtual Reality

A couple months ago I received my first virtual reality (VR) headset, and have been experimenting with various games and apps since. (Here is my initial review.) As a neuroscientist, it is a fascinating demonstration of how our brains construct our experience of reality.

What I and everyone who has used my gear has experienced is surprise at how visceral VR can be. It’s just a big video, right, so why do our lizard brains react so strongly? The most dramatic example is an app called “The Plank Experience”. In it you take an elevator up to a high floor in a skyscraper. The door opens to reveal a plank going out over the street far below. Everyone so far is frozen at the moment the doors open and they see the chasm below them. Some can walk out onto the virtual plank, but most people hesitate and at least one person bailed and would not do it.

What is interesting is that when I stepped out onto the plank, I completely 100% knew that I was standing on the carpet in my office, totally safe and at no peril at all. However, the part of my brain that knew I was safe was in conflict with a deeper and more primitive part of my brain that was screaming, “Danger, danger.”  It took an effort of will to overcome the fear, but I could not make the fear go away.

Let me describe one other part of the VR experience and then I’ll discuss what is going on neurologically. Motion sickness has been a major challenge for VR. All of the games and apps I have used so far have an option (usually the default) where if you have to move your character in the VR world you do it by teleporting. You use the control to place an X on the floor where you want to go, and then you are instantly in that location. This type of movement does not produce any motion sickness.

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Feb 12 2018

Significant but Irrelevant – Study on Correcting False Information

A study from a few months ago is making the rounds due to recent write ups in the media, including Scientific American. The SA titles reads: “Cognitive Ability and Vulnerability to Fake News: Researchers identify a major risk factor for pernicious effects of misinformation.”

The study itself is: ‘Fake news’: Incorrect, but hard to correct. The role of cognitive ability on the impact of false information on social impressions. In the paper the authors conclude:

“The current study shows that the influence of incorrect information cannot simply be undone by pointing out that this information was incorrect, and that the nature of its lingering influence is dependent on an individual’s level of cognitive ability.”

So it is understandable that reporters took that away as the bottom line. In fact, in an interview for another news report on the finding one of the authors is quoted:

“Our study suggests that, for individuals with lower levels of cognitive ability, the influence of fake news cannot simply be undone by pointing out that this news was fake,” De keersmaecker said. “This finding leads to the question, can the impact of fake news can be undone at all, and what would be the best strategy?”

The problem is, I don’t think this is what the study is saying at all. I think this is a great example of confusing statistically significant with clinically significant. It is another manifestation of over-reliance on p-values, and insufficient weight given to effect size.

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Feb 06 2018

Mindfulness No Better Than Watching TV

A recent systematic review and meta-analysis of the effects of mindfulness meditation on prosocial behavior found, essentially, that there is no evidence that it works. I find these results entirely unsurprising, and they yet again highlight the need for rigorous research before concluding that a phenomenon is real.

As I discussed recently on SBM, mindfulness meditation is the practice of sitting quietly, focusing inward and on the present, and avoiding mind wandering or daydreaming. The recent review I discussed on SBM found that the research into mindfulness, however, does not use a uniform or operationalized definition. That is critical to good science – you need to carefully define something before you can do research on it.

It is especially important to specifically define a concept in order to do research into the question of whether or not the phenomenon is real. If your question is, “Does X exist,” you better have a very specific definition of what X is. Otherwise it is easy to misinterpret the evidence, or to wiggle out of evidence that X does not exist.

The best example of this in medicine is acupuncture. Acupuncture is defined as sticking thin needles into acupuncture points – except when research shows that it does not matter where or even if you stick the needles, then acupuncture can be something else, which is vaguely defined.

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Feb 05 2018

Neuro-Quantum Entanglement Pseudoscience

On the Canadian Entrepreneur show, Dragon’s Den, the dragons were given a demonstration of a clip (that’s right, a small metal clip like you would use to hold papers together or put in your hair) that the creator claimed would improve your balance, strength, and health through the power of “quantum entanglement.” The clips, called Neuro Connect, were “developed” by a chiropractor and his partner. The Dragons fell for it, amazed by the demonstrations, and invested $100,000 for a 30% share.

The show aired, giving a huge boost to the company’s sales. However, the way the show works, even when the Dragons make a deal on camera, the deal is contingent on them doing due diligence for confirmation. When they did they found that there were serious scientific objections to the claims being made by company selling the clips, NeuroReset Inc. The deal was off.

But this did not stop the show from airing. The public did not get the benefit of their due diligence – they protected themselves, but completely threw their audience under the snake oil bus.  Canadian news outlet CBC contacted the producer to get their response:

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