Archive for the 'Neuroscience' Category

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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124 responses so far

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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Feb 01 2018

A Case of Brain Death

Published by under Neuroscience

The New Yorker magazine’s latest issue features an article about the sad story of Jahi McMath. Jahi was a 13 year old girl who four years ago underwent a routine tonsillectomy to treat severe snoring and breathing problems. Unfortunately the surgery was complicated by severe bleeding post-op, leading eventually to a cardiac arrest. After a sustained effort at resuscitation the doctors did manage to get her heart working, but by that time her brain was severely damaged by lack of oxygen. She was declared clinically brain dead.

This is not where the story ends, however. Since then the family has refused to accept the diagnosis of brain death, prompting a prolonged conflict with the hospital. Eventually Jahi was removed by the family to an undisclosed hospital in New Jersey, and ultimately discharged to home care, where she remains.

I have had several questions about the story, and I will try to add some insight, with the caveat that I have no direct knowledge of the medical facts of the case beyond what is reported in the New Yorker article and elsewhere. I have not examined her, spoken directly to anyone involved in her care, or reviewed medical records. But there is a lot of information in the public domain and I can speak to that information, as far as it is accurate.

There are several layers to this story. There is a legal layer, as the family is suing the hospital for malpractice. I will not address that aspect of the case. There is the neurological layer – what is brain death and is this girl dead? There is also a personal and cultural layer here in terms of the family’s reaction. Let me start with some thoughts on this.

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Jan 16 2018

More Mental Illness Denial

Published by under Neuroscience

I was recently pointed to this article by Johann Hari in The Guardian that takes a critical look at depression and the treatment for depression. Unfortunately, it turned out to be nothing more than the usual mental-illness denial talking points, misdirection, and obfuscation.

As you will see if you follow the link above, this is a well-worn topic here. The basics are this – there are those, for various reasons, who are engaged in what I think qualifies as mental-illness denial. They include scientologists, because they push their cult/religion as an alternative to psychiatry. There are also those who follow Szasz who saw psychiatry as a mechanism for political oppression. I also find denial at times among rival professions who want to take psychiatry down a peg or two (often they just confuse their experimental expertise for clinical expertise – always a problem).

They all tend to have in common the core claim that “mental illness” is a fiction. How can thoughts be diseased? This is ultimately a straw man that confuses different types of illness. Some illness is based in biological pathology – cells are damaged, deteriorating, poisoned, genetically flawed, or essentially not functioning within healthy parameters for some reason. You can often see the pathology in a biopsy or measure it with some physiological parameter.

But not all illness is pathological disease. There are also disorders in which some biological function is outside of healthy parameters without clear pathology. The brain in particular is prone to this type of illness, and that is because brain function depends on much more than just the health of its cells (neurons and glia). Even healthy brain cells can be organized in such a way that their neurological function is compromised.

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Jan 04 2018

Backfire Effect Not Significant

Previous research has shown that when confronted with a factual statement that appears to go against an ideologically held belief, a percentage of people tested will move their position away from the factual information – a so-called “backfire effect.” This notion was rapidly incorporated into the skeptical narrative, because it seems to confirm our perception that it is very difficult to change people’s minds.

However, more recent research suggests that the backfire effect may not exist, or at least is exceedingly rare. A recently published series of studies puts a pretty solid nail in the coffin of the backfire effect (although this probably won’t be the last word).

To be clear, people generally still engage in motivated reasoning when emotions are at stake. There is clear evidence that people filter the information they seek, notice, accept, and remember. Ideology also predicts how much people will respond to factual correction.

The backfire effect, however, is very specific. This occurs when people not only reject factual correction, but create counterarguments against the correction that move them further in the direction of the incorrect belief. It’s probably time for us to drop this from our narrative, or at least deemphasize it and put a huge asterisk next to any mention of it.

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Dec 08 2017

In Half a Second

Published by under Neuroscience

If you have not yet read Daniel Kahneman’s book, Thinking, Fast and Slow, I recommend it. I have discussed its basic principles here many times, and I am reminded of it by a new study that evaluates how we quickly size-up groups of people.

Before we get to the study, here is a quick overview. Kahneman and Tversky did the foundational research into cognitive biases and heuristics – ways in which our thinking is biased or constrained. Kahneman calls this system 1 thinking, or intuitive thinking, which is the fast sort. There is also system 2 thinking, which is slow and analytical.

He admits that these are metaphors, there probably aren’t two distinct biological systems in our brains, but they help us think about the different ways in which we think. Actually, given that our brains are hierarchical, the two-system model may be based in biology to some extent. There are the primitive older parts of our brain that are more system 1 – instinctive, emotional, and fast. Then there is the neocortex – which gives us executive function, and slow deliberative decision-making. I don’t think you can make a clean separation, but it is a useful schematic that is probably more true than not.

In any case, the two systems work together to shape our perceptions and decision-making. The idea is that we evolved rapid-response cognitive systems that makes quick and dirty judgments that are accurate enough and biased in whatever direction favors survival. We can then follow up these quick perceptions with more careful analysis when we have time.

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Dec 04 2017

The Causes of Science Denial

Over the last few decades the challenges we face promoting science and critical thinking have become greater, but so have the tools at our disposal. The “science of anti-science” has been progressing nicely, and we now have a much more nuanced view of what we are up against.

Carl Sagan was fond of saying that, “Pseudoscience is embraced, it might be argued, in exact proportion as real science is misunderstood.” That was the conventional wisdom among skeptics at the time (quote from Demon Haunted World, published in 1997) – that the problem of pseudoscience or science-denial was essentially one of information deficit. Correct the deficit, and the science-denial goes away. We now know that the real situation is far more complex.

To reduce the acceptance of pseudoscience or the rejection of real science, we need to do more than just promote scientific literacy. We also need to understand what is driving the pseudoscience, and we need to give critical thinking skills.

A recent publication of a series of studies looking at the roots of science rejection is a nice cap on this research: Not All Skepticism Is Equal: Exploring the Ideological Antecedents of Science Acceptance and Rejection.

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