Archive for the 'Neuroscience' Category

Jul 21 2015

Expertise and the Illusion of Knowledge

Published by under Neuroscience

In general people think they know more than they do. This is arguably worse than mere ignorance – having the illusion of knowledge. Psychologist David Dunning (of the Dunning-Kruger effect) recently wrote in an editorial about his own study (which I discuss here):

“What’s curious is that, in many cases, incompetence does not leave people disoriented, perplexed, or cautious. Instead, the incompetent are often blessed with an inappropriate confidence, buoyed by something that feels to them like knowledge.”

Dunning was discussing the “ignorant mind.” Further, self-perceived expertise does not protect against this effect and in fact may make it worse. A new paper published in the latest issue of Psychological Science, When Knowledge Knows No Bounds: Self-Perceived Expertise Predicts Claims of Impossible Knowledge, presents four studies exploring the relationship between perceived expertise and the illusion of knowledge.

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Jun 22 2015

Inside Out – A Neuroscience Metaphor

Published by under Neuroscience

I recently saw the new Pixar movie, Inside Out, which follows the inner workings of a young girl’s mind. (I will be discussing the premise, rather than the plot, of the movie so only mild spoilers.) As a neuroscientist of course I was interested in the metaphors that the writers chose to represent the workings of the human brain. They made many good choices, but there was also some interesting elements missing or misplaced.

Of course, I understand this is a movie. The writers made choices to make the movie enjoyable to children as well as adults, which means they likely made some choices to keep things simple. Other choices may have been driven by the needs of the plot, and still others simply to be cute and entertaining. I get it – this wasn’t a neurology lesson. For example, IMDb notes:

“The writers considered up to 27 different emotions, but settled on five (Joy, Sadness, Disgust, Fear and Anger) to make it less complicated. Some of the major emotions that ended up being cut included Surprise, Pride, and Trust.”

Central Command

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Jun 09 2015

Injectible Brain Electrodes

Charles Lieber with his team at Harvard University have developed a flexible mesh network of electrodes that can be injected through the skull, unfolding onto the surface of the brain. This technology could be a significant advance in our ability to study the brain.

Neuroscientists are trying to map the brain in as much detail as possible, creating what is being called the “connectome” (reminiscent of mapping the human “genome”).

There are about 87 billion neurons in the adult human brain. Each neuron is capable of making up to around 10,000 connections to other neurons, which means the total connections in the brain is somewhere around a quadrillion. The saying goes that neurons that wire together fire together, so the pattern of connections determines the pattern of electrical activity in the brain.

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May 28 2015

How the Brain Chooses Where to Go

Published by under Neuroscience

Neuroscientists are making progress mapping out the cortical pathways that allow us to know where we are and navigate to a desired location. A recent study adds another bit of information to this growing picture.

The Nobel Prize for Physiology or Medicine for 2014 was given to several scientists, Dr. John M. O’Keefe, Dr. May-Britt Moser and Dr. Edvard I. Moser, for their collective research in working out the basic neurological function that underlies our ability to place ourselves in our environment and to navigate around. O’Keefe identified place cells. A specific place cell will fire when we are in a specific location. Different patterns of place cells firing represent different locations.

These place cells are found in the hippocampus, specifically area CA1. O’Keefe also found that the place cells have memory function, and are therefore critical to our ability to remember specific locations.

Moser and Moser extended this work by finding grid cells in the entorhinal cortex. This area connects heavily with CA1, and contains cells that behave like the place cells. However, the grid cells are arranged in a hexagonal grid, and they fire in sequence as rats move through their environments. The grid cells therefore seem to be a literal map of the environment, and track our movement through the environment, while the place cells tell us where we are.

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May 18 2015

Ex Machina and AI

Published by under Neuroscience

I saw Ex Machina this weekend. If you haven’t seen the movie yet, mild spoiler alert – I will try to avoid any major reveals, but I will be discussing major aspects of the movie.

First, it’s an excellent film. I highly recommend it. It was both entertaining and thought provoking. Writer/Director Alex Garland clearly understands the topic of artificial intelligence (AI), and is also a talented filmmaker. I was particularly impressed by how much he accomplished with such a sparse film. The majority of the film takes place in one location and with three characters, but he quickly established those characters and the primary tensions that drive the film.

He also manages to weave in a fairly deep commentary on the nature of consciousness and creativity, the nature of AI, and all with a subtext of oppression, misogyny and male-female relationships. I still feel like I am missing a lot of subtext in this film, which will require at least a second viewing and a lot more thought.

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Apr 02 2015

Lunar Cycle Effects Busted

When I was an intern doing a rotation in the emergency department, on one particularly busy shift a nurse commented (to no one in particular) that it must be a full moon. I habitually look at the moon and generally know what phase it is in (right now it is a waxing gibbous, almost full), and so I knew at the time that in fact there was a crescent moon in the sky. I informed her of this. She gave a disappointed look and then went on with her work without any apparent further thought on the matter.

The episode struck me at the time. It seemed to me that I just witnessed a clear example of confirmation bias – what if it had been near a full moon? That would have confirmed her prior belief in a lunar effect, while this negative correlation was brushed aside and likely did not have any negative effect on her belief. (Although, my interpretation and memory of this event can itself be an example of confirmation bias regarding confirmation bias.)

Belief in the so-called lunar effect, that the phases of the moon exert an influence on human behavior with the most common element being a full-moon inducing extreme behavior, is very common. In my experience it is one of the most common pseudoscientific beliefs I encounter in the general public. One survey indicates that 43% of adults believe in the lunar effect, especially mental health professionals, including nurses.

When someone expresses such a belief to me I often use it as an opening to discuss skeptical principles. While belief in the lunar effect is widespread, it is usually not part of any emotionally held religious or ideological belief. It is therefore an excellent teaching opportunity. One question I like to ask is, “how do you think that works?” The most common answer I receive is probably the least plausible – that the tidal effects of the moon influence the brain because the brain is sitting in water (spinal fluid).

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Mar 26 2015

Fox News, the NFL, and Concussion Denial

Published by under Neuroscience

I have been a fan of professional football since my college days (go Pats) but I also recognize that it is a brutal sport prone to injuries. In recent years awareness of the true neurological risk of concussions, especially repeated concussions, has been increasingly coming to light. This may cause some cognitive dissonance among fans, players, and anyone involved with the NFL, including broadcasters.

Recently Fox News published and article in which Dylan Gwinn writes:

Don’t look now, but concussions have become the new global warming: a debate where “consensus” trumps evidence, and heroes and villains are determined by their stances on an issue where the science is bogus at worst and murky at best.

This is classic FUD – fear, uncertainty, and doubt, the primary tactic of those who find reality not to their liking in some particular aspect.

Gwinn creates the classic false dichotomy between consensus and evidence. What if the consensus is based upon scientific evidence, and in fact the consensus of experts is the best way for non-experts to understand what the evidence actually says.

Further, all science is murky, at least to some degree. The clarity of a scientific conclusion exists along a spectrum from genuinely controversial to rock solid, but scientific evidence is always complex, subject to multiple interpretations, and incomplete. It doesn’t take much creativity to portray any scientific conclusion (even those at the rock solid end of the spectrum) as murky. Creationists are evidence of that.

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Feb 27 2015

What Color Is This Dress? It’s An Optical Illusion

Published by under Neuroscience

This is pretty amazing – almost as much for how quickly this has gone viral as for the effect itself. There is now an intense debate going on in the intertubes over whether this dress is black and blue or white and gold. Take a look and decide for yourself. Buzzfeed has a poll which currently puts it at 72% white and gold, and 28% black and blue. Right now there are about 2 million votes, so that is probably statistically significant.

I see black and blue, no matter what screen or version of that picture I look at. It does not seem to be an issue with the monitor or viewing conditions.

The reason, in my opinion, this has gone so viral so quickly is that people are legitimately freaked out by the realization that how they see the world is ultimately a subjective construction of our brains. Taylor Swift tweeted about the debate:

“I don’t understand this odd dress debate and feel like it’s a trick somehow. I’m confused and scared. PS It’s OBVIOUSLY BLUE AND BLACK.”

That about sums it up. She thinks it must be a trick (it is – a trick of the brain), and is scared and confused. At the same time she is caps-lock-certain that her perception of the dress’s color is the objective truth.

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Feb 23 2015

ADHD Is Real

Published by under Neuroscience

Attention Deficit Hyperactivity Disorder (ADHD) has long been a target of those who dislike the very concept of mental disorders. This is partly because the emotional stakes are high – the diagnosis often results in children being treated with stimulants. Opposition to the concept of ADHD also reflects fundamental misunderstandings about medicine.

A recent opinion piece in The Blaze by Matt Walsh reflects this deep misunderstanding and unease with the concept of mental illness.

Throughout the piece he uses the terms “disease” and “disorder” interchangeably, without defining either. The distinction is important, because it relates to how medicine defines diagnostic entities. Not all diagnoses are created equal. I spend a great deal of time teaching medical students to have a sophisticated and nuanced understanding of the labels they will be attaching to their patients.

As with every branch of science, labels are used as placeholders of our understanding of phenomena, and also as a necessary contrivance to allow technical communication among experts, in the scientific literature, and also to the public. In medicine we need labels for certain practical applications, such as documentation, epidemiology, drug indications, reimbursement, and research. Labels are a scientific tool, and they need to be understood to be used properly.

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Feb 06 2015

Did Williams Lie?

Published by under Neuroscience

Memory is a slippery thing. We know from countless psychological studies that memories can easily be fabricated, they will alter over time, and details will shift to enhance the emotional theme of the story. Further, we tend to personalize stories – over time we remember events that happened to our friends as happening to us.

Recently NBC host Brian Williams was caught telling a version of an event that happened 12 years ago that differs from the version others recall, and the version that he himself told at the time. He and his cameraman were in a helicopter group during the Iraqi war in 2003. The leading three helicopters, which were 30-60 minutes ahead, were forced to land upon taking small arms fire, with one copter being hit by an RPG. Williams’ copter also landed when they arrived at the lead group in order to avoid being fired on. The group had to be rescued by ground troops and tanks.

The problem is that Williams’ retelling of this story has shifted a bit over the years, until in the last couple of years he puts himself in the helicopter that was hit by fire. Stars and Stripes gives the timeline of this shifting story. So what’s going on here.

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