Archive for the 'Neuroscience' Category

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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6 responses so far

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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160 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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5 responses so far

Mar 08 2016

What Causes Overconfidence?

Published by under Neuroscience

overconfidencePeople are overconfident. That is a clear signal in psychological research that is reliably replicated. At this point it can be taken as a given. The brain is a complex machine, however, and any one factor such as confidence interacts in multiple and complex ways with many other mental factors.

Questions that have not been fully addressed include the possible causes and effects of overconfidence. Dunning and Kruger famously isolated one factor – overconfidence (the difference between self-assessment and actual performance) increases as performance decreases. This effect (called the Dunning-Kruger effect) is offered as one explanation for what causes overconfidence – the competence to assess one’s own competence.

A new series of studies looks at another factor that may influence overconfidence, ideas about the nature of intelligence itself. Joyce Ehrlinger and her colleagues performed three studies looking at the effect of two theories of intelligence on overconfidence. The two theories in question are the notion that intelligence is largely fixed (called the entity theory) vs the idea that intelligence is highly malleable (called the incremental theory).

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282 responses so far

Dec 22 2015

The Genetics of Intelligence

Published by under Neuroscience

DNA1A new study published in Nature Neuroscience explores genes that correlate with intelligence in healthy individuals as well as those with epilepsy and cognitive disorders. They looked at the brains of patients undergoing surgery for epilepsy, which means that a sample of their brain tissue was available. This allowed them to find which genes were highly expressed in brain tissue.

They then combined this data with other data sets including genetic analysis and IQ testing on healthy individuals and those with developmental disorders. They analysed thousands of genes to find those that correlate with differences in IQ.

They found that there are two sets of genes, which they are calling M1 and M3, that highly correlate with intelligence. M3 contains 150 genes that are tightly developmentally regulated. Keep in mind these are genes that they know are highly expressed in the brain.

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24 responses so far

Dec 10 2015

Delayed Gratification and the Brain

Published by under Neuroscience

Neuroscientists, both psychologists and neurobiologists, have been studying the phenomenon of delayed gratification. This is the ability to make choices that deny oneself an immediate or short-term benefit in order to garner a greater long term benefit. A recent study looks at the genetics associated with the ability to delay gratification.

Researchers use a study paradigm known as the marshmallow test to study impulsivity and the ability to delay gratification. The first such studies were conducted in the 1960s and 70s by Walter Mischel, then at Stanford University. Children in the study were offered a small treat, such as a marshmallow, immediately, or were told they could have two treats if they were willing to wait 15 minutes, during which time the researcher left the child alone with the marshmallow.

Follow up studies found that children who were able to hold off on eating the marshmallow had numerous better life outcomes – better academic performance, more successful marriages, better careers, and lower BMI.

Not surprisingly, children with ADHD perform worse on the marshmallow test.

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11 responses so far

Dec 08 2015

What Are You Afraid Of?

Published by under Neuroscience

Fear is an adaptive emotion, phylogenetically ancient, and anatomically located mostly in the amygdala, which is part of the limbic system. Understanding fear, however, is about more than neuroanatomy. It is interesting to think what people generally fear, why, and what do they do about it.

Fear is an anxious feeling that can focus on either a current active threat (like being chased by a predator) or on the anticipation of a future negative event. It’s easy to see how that feeling would be adaptive – we worry about bad things happening in the future so that we will take action to prevent or at least mitigate them.

What We Fear?

Psychologists have identified five basic fears, out of which most other fears are based. They are: fear of death, mutilation, loss of autonomy, separation, and “ego death” which is the fear of humiliation or shame.

Despite the obvious adaptive function of fear, many people fear the wrong things, meaning that their fear and anxiety is not proportional to actual threat. This mismatch is maladaptive, so why is it the case?

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25 responses so far

Dec 03 2015

Detecting BS

A new study is getting a lot of attention, partly because of its provocative title: On the reception and detection of pseudo-profound bullshit. It also seems that people generally like to hear stories about how dumb other people are. That is why I often emphasize that such studies are not about “other” people, they are about people.

In this case, however, the researchers do find that there are subsets of subjects who react differently to what they call “pseudo-profound bullshit.” They write:

Here we focus on pseudo-profound bullshit, which consists of seemingly impressive assertions that are presented as true and meaningful but are actually vacuous. We presented participants with bullshit statements consisting of buzzwords randomly organized into statements with syntactic structure but no discernible meaning (e.g., “Wholeness quiets infinite phenomena”).

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77 responses so far

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