Archive for the 'Neuroscience' Category

Aug 18 2016

Diagnosing Mental Illness in Presidential Candidates

Published by under Neuroscience

trump-duh-e1453305835771CBS News Sunday Morning contributor Nancy Giles says that, in her opinion, Donald Trump is “clinically insane.” I have to wonder how “clinically insane” is different from regular “insane.”

I think the implication here is that this is a real psychiatric diagnosis of insanity, and not just a colloquial use of the word, like “that’s crazy.” Giles is implying that Trump has a mental illness, not just that she vehemently disagrees with his attitudes and temperament.

Meanwhile, there are conspiracy theories on the right about Clinton’s health and her “bizarre behavior,” with wild speculations about seizures and Parkinson’s disease.

A recent editorial on Medscape Psychiatry by Nassir Ghaemi asks a very interesting question, Is Psychoanalyzing Our Politicians Fair Game?

Armchair vs Professional

There is a range of behaviors going on here, and to some extent they need to be considered separately. Ghaemi was writing exclusively about psychiatrists (and to some extent psychologists) and their duties to patients, the profession, and as citizens.

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18 responses so far

Aug 12 2016

Augmented Reality and Mental Workload

fNIIRSVirtual reality (VR) and augmented reality (AR) applications are already here, but they still have not hit the steep part of the curve. We appear to be right at the beginning. We are about to experience the rapid adoption and experimentation with this new technology, and it will be interesting to see what applications become popular, and how people end up using these technologies. This is like predicting prior to the iPhone what smart phone apps will be popular.

For background, VR involves wearing goggles that fill your entire field of vision, so that you appear to occupy an entirely virtual world. When you physically move your head, your virtual perspective changes accordingly, so you can actually look around your virtual world.  Wearable devices like gloves are used to manipulate the virtual world.

Augmented reality is similar, but instead of immersive goggles you wear transparent glasses (like Google Glass) or use a handheld device with a camera (like Pokemon Go) which overlays virtual information onto the real world.

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10 responses so far

Aug 09 2016

Making the Non-Existent Disappear

Hieronymus_Bosch_051If I told you I could make something nonexistent disappear, you probably would not be very impressed with that as a magic trick. However, magic is all about misdirection. If I could make you think you saw an object that was never there, and then make it disappear, that could be quite impressive.

Psychology and Magic

Increasingly psychologists, neuroscientists, and magicians are converging upon a model of how our brains construct our perceptions of reality. Magicians actually had a head start as they have been working out practical ways to fool human perception for centuries. Psychologists started taking note in the late 19th century, but really have only been seriously examining the techniques of magicians in the last decade or so. Psychologists now routinely use magic tricks as part of experimental setups.

The basic picture that has emerged is that our sensory perceptions have both bottom-up and top-down components. The bottom-up components are essentially using the raw sensory input and constructing an image from that, then passing that construction on to higher brain levels that interpret the image and give it emotional meaning. Top-down construction works the opposite way, with the higher brain areas communicating their expectations to the primary sensory areas and influencing their construction.

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Jul 25 2016

A Tougher Turing Test

exmachinsert5In 1950 Alan Turing, as a thought experiment, considered a test for telling the difference between a human and an artificial intelligence (AI). If a person had an extensive conversation with the AI and could not tell them apart from a real person, then that would be a good indication that the AI had human-like intelligence.

This process became known as the Turing Test, and every year various groups administer their version of the Turing Test to AI contestants. The test has limits, however, and is generally considered to be too easy. It is also dependent on the skills of the human questioner.

Parsing Language

A recent AI contest used a different approach, the Winograd Schema Challenge (WSC).This is one of many alternatives to the Turing Test that are being explored. Here is the format of the challenge:

  1. Two entities or sets of entities, not necessarily people or sentient beings, are mentioned in the sentences by noun phrases.
  2. A pronoun or possessive adjective is used to reference one of the parties (of the right sort so it can refer to either party).
  3. The question involves determining the referent of the pronoun.
  4. There is a special word that is mentioned in the sentence and possibly the question. When replaced with an alternate word, the answer changes although the question still makes sense (e.g., in the above examples, “big” can be changed to “small”; “feared” can be changed to “advocated”.)

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270 responses so far

Jul 05 2016

A Psychiatrist Falls for Exorcism

demon_1John Mack was a Harvard psychiatrist who famously fell for his patient’s own delusions. He came to believe that some of his patients were actually abducted by aliens. He was never able to provide any compelling evidence of this, just their testimony. Despite being a professional in mental health, he lacked the skeptical skill set necessary to see his errors.

We now have another very similar case – a Yale trained psychiatrist, Richard Gallagher, who has fallen for his patients delusions that they are possessed by demons. His editorial in the Washington Post is stunning for its utter lack of skeptical awareness.

I am sometimes questioned by well-meaning but confused scientists who do not understand the role that scientific skepticism plays in society. Isn’t science itself enough? Aren’t all scientists skeptical, or at least they should be?

What they miss is that skepticism is a real and deep intellectual skill set that works with science. It includes specialized knowledge that is not necessarily acquired during scientific training. There are frequent examples of this, and Gallagher’s article is now a prime example as well. He hits almost every true-believer trope there is. Ironically he has created a classic case study in the need for scientific skepticism.

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469 responses so far

Jun 21 2016

The Improbability Principle

strawberrymoonPeople generally suck at statistics. Our innate sense of how likely something is does not accord very well with reality, especially for large numbers.

But don’t worry, this just means you have to think a little harder about how likely things are. David Hand writes about this in his 2014 book: The Improbability Principle: Why Coincidences, Miracles, and Rare Events Happen Every Day. This is making the rounds again in the media because of the recent “rare” astronomical events.

Yesterday the Summer Solstice coincided with the Strawberry Moon – the first full moon in June. The last time this happened was in 1967. Recently we have seen “rare” transits of Mercury and Venus across the sun.

These events are not that rare, and I really don’t see what the fuss is all about (I guess the media is desperate for anything they can hype.) Don’t get me wrong, I love astronomical events, it is their rarity that I think is overhyped.

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20 responses so far

Jun 13 2016

Stem Cell Treatment for Multiple Sclerosis

ms cortex-above-ventriclesThere has been a lot of reporting about a new stem cell treatment for multiple sclerosis (MS). The results are genuinely interesting, even exciting, but preliminary and need to be put into perspective.

MS is an autoimmune disease of the central nervous system, affecting the brain and spinal cord. Actually, it is a category of several diseases that are largely defined clinically, such as relapsing remitting MS and chronic progressive MS. These distinctions are meaningful because they do predict response to certain existing treatments. Relapsing forms of MS tend to respond to chronic immune modulating drugs, while progressive forms tend not to respond.

The immune system in MS patients is faulty, targeting the myelin around axons in the brain and spinal cord. Myelin is the insulation that allows axons to conduct. When the myelin breaks down due to inflammation this slows conduction, and if severe enough can even stop it completely. Symptoms depend on where these inflammatory lesions occur in the nervous system. If a motor pathway is affected, then weakness will result.

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May 31 2016

Postdictive Illusion of Choice

Published by under Neuroscience

fmri brainDo we truly have free will? This is a vexing question, and as with the question of consciousness, there are complementary philosophical and neuroscientific approaches. Philosophy gives thoughtful possible answers given what we know, but neuroscience advances what we know.

As I have discussed many times before, the totality of neuroscientific evidence strongly supports the conclusion that consciousness is a phenomenon of brain function. Dualist philosophies, those that posit that consciousness is anything other than or in addition to brain function, are simply trumped by the scientific evidence.

Free will, however, is a thornier question and more entangled with the philosophy. There are those who maintain that free will is entirely an illusion, because our brains are machines so they must follow physical laws which determine their behavior, hence our behavior, therefore no true free will. While I do not think this can reasonably be refuted, some think the real question is whether or not we make choices. If we do, whether or not those choices are free from physics, then perhaps that can be considered a form of free will.

Putting aside the philosophical question here, the neuroscientific question is this – to what extent do we make conscious choices vs subconscious choices?

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161 responses so far

Apr 15 2016

Neural Bypass Helps Quadriplegic Man Use His Arm

Published by under Neuroscience

neuralprostheticI have been following and writing about the development of neural prosthetics and brain-machine interfaces as the technology has been advancing over the last decade. These are techniques that read electrical signals from the brain, process those signals through a computer algorithm, and use them to control some external device.

Another milestone has been reached in this technology. Researchers at Ohio State University implanted electrodes on the motor cortex of a man with a mid cervical quadriplegia. He cannot use his hands or legs. The output from these electrodes was then connected to a sleeve over his right forearm that could electrically stimulate his muscles in specific patterns to produce useful movements, like grasping and releasing.

After several hours of practice:

The system provided isolated finger movements and the participant achieved continuous cortical control of six different wrist and hand motions. Furthermore, he was able to use the system to complete functional tasks relevant to daily living.

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20 responses so far

Mar 14 2016

Patients Prefer Video to Face-to-Face Consultation

atmThere are now many aspects of my life in which I prefer to interact with a computer rather than a person. When I stop to fill up my tank or remove some cash from my bank account, I can do so quickly and efficiently by interfacing directly with an automated machine. It is interesting to think about exactly why this is, but first let me discuss the findings of a new study looking at this very question.

Dr. Matthew Winter and his fellow researchers presented the results of a randomized trial at the European Association of Urology 31st Annual Congress in which they compared giving informed consent via video vs in person prior to a urological procedure.

The study randomized 88 patients to either have a face-to-face consultation with the surgeon, or to viewing a prepared video including animation to describe the procedure. They then quizzed them on their knowledge of the procedure, and did a follow up cross-over in which the groups switched and then were re-tested.

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