Archive for the 'Neuroscience' Category

Sep 08 2017

How People Thrive

Published by under Neuroscience

happy-facesThere is a science to happiness and to what we might call thriving (sometimes called flourishing) – not just surviving, but being happy and fulfilled. Obviously any such phenomenon is going to be very complex and variable, but some clear patterns are emerging in the psychological literature. A recent study by Brown et al reviews that literature in an attempt to summarize what we know about thriving.

Brown identifies a number of factors that contribute to thriving, but the core seems to come down to two things: being confident and being good at something. Other researchers looking at the same question have had a slightly different emphasis, but I think are essentially saying the same thing. Thriving correlates with living with purpose, for example. Other studies emphasize community and having a belief system (which may just be a proxy for having a purpose). Having a purpose in life has even been associated with better physical health in older adults.

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36 responses so far

Jul 31 2017

The Goldwater Rule Revisited

Published by under Neuroscience

goldwaterIn 1964 Fact Magazine published an article titled: “1,189 Psychiatrists say Goldwater is Psychologically Unfit to be President!”  They were later sued successfully for defamation. This incident led the The Goldwater rule – Section 7 in the American Psychiatric Association’s (APA) Principles of Medical Ethics, which states it is unethical for psychiatrists to give a professional opinion about public figures they have not examined in person, and from whom they have not obtained consent to discuss their mental health in public statements.

This rule has held sway for the last 50 years. However, recently the American Psychoanalytic Association (APsaA) e-mailed its members to inform them that they are not constrained by the Goldwater rule. So which stance is correct?

There are two competing ethical principles at stake. The first is the ethical responsibility of professionals not to cause harm to someone else by making public statements they have no business making. This is especially true when it comes to psychiatric diagnoses, because they carry a heavy and (in my opinion) unjustified stigma. The mere fact of being a public figure does not mean that medical professionals are free to bypass confidentiality and consent to make public speculations about your mental health.

Further, psychiatric diagnoses are especially complex and subjective. In order to make a accurate diagnosis you need a lot of background information about a person, and you need some professional interaction. This should ideally be a personal examination, however watching a video of another professional conducting an examination could suffice. But even then, the purpose of psychiatric diagnoses is to guide therapy. They are still fuzzy and subjective entities. It seems profoundly unethical to turn them against an individual, and use a formal diagnosis to medicalize their personality and behavior for non-therapeutic purposes.

When dealing with politicians, it is further very difficult for professionals to filter out their own ideology or personal feelings. It becomes too easy to use the tools of medicine for political fighting.

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184 responses so far

Jul 10 2017

Why Are We Conscious?

Published by under Neuroscience

brain3While we are still trying to sort out exactly what processes and networks in the brain create consciousness, we are also still uncertain why we are conscious in the first place. A new study tries to test one hypothesis, but before we get to that let’s review the problem.

The question is – what is the evolutionary advantage, if any, of our subjective experience of our own existence? Why do we experience the color red, for example – a property philosophers of mind call qualia?

One answer is that consciousness is of no specific benefit. David Chalmers imagined philosophical zombies (p-zombies) who could do everything humans do but did not experience their own existence. A brain could process information, make decisions, and engage in behavior without actual conscious awareness, therefore why does the conscious awareness exist?

This idea actually goes back to soon after Darwin proposed his theory of evolution. In 1874 T.H. Huxley wrote an essay called, “On the Hypothesis that Animals are Automata.”  In it he argued that all animals, including humans, are automata, meaning their behavior is determined by reflex action only. Humans, however, were “conscious automata” – consciousness, in his view, was an epiphenomenon, something that emerged from brain function but wasn’t critical to it. Further he argued that the arrow of cause and effect led only from the physical to the mental, not the other way around. So consciousness did nothing. We are all just passengers experiencing an existence that carries on automatically.

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89 responses so far

Jul 07 2017

Conspiracy Thinking and the Need for Certainty

conspiracy1The world is horrifically complicated and humans have developed a number of strategies to deal with that complexity. These strategies are necessary but imperfect. There is also always a trade-off, sacrificing detail and nuance for understandability.

One such strategy I have written about often is the need for simplicity. A saying, attributed to Albert Einstein with good references, goes: “Everything should be as simple as it can be, but not simpler.” He was talking about the art of making complex scientific knowledge accessible without making it wrong. Unfortunately, the desire for simplicity often leads to oversimplification, with important details and concepts lost or distorted.

There is another related strategy psychologist call the need for cognitive closure. One reference defines this need as:

“As a dispositional construct, the need for cognitive closure is presently treated as a latent variable manifested through several different aspects, namely, desire for predictability, preference for order and structure, discomfort with ambiguity, decisiveness, and close-mindedness.”

It is easy to see the trade-offs here. On the one hand it is good to be intellectually flexible, open-minded, and comfortable with ambiguity and uncertainty. Yet, this disposition can predispose one to indecisiveness, the “paralysis of analysis.” At some point we have to commit, even if tentatively. Structure and order in thought can also be positive things.

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23 responses so far

Jul 06 2017

The Brain’s Wiring

Published by under Neuroscience

connectome5Cardiff University has released its latest scans of the wiring of the human brain. This now adds to a similar project in the US funded by the NIH.

The result is a stunning image of all the axons in the human brain – the wires that conduct signals and form networks and connections to other parts of the body. In addition to these wires there are also the neurons, which are the cell bodies of which the axons are part, and the glia, which are other cells in the brain that serve support functions but also play a role in modulating neuronal function.

These wiring images are part of various connectome projects – attempts at fully mapping all the connections within the human brain and their functions. These latest images from Cardiff are the result of the Siemens 3 Tesla Connectome MRI system. Essentially we are seeing the result of advances in both hardware and software technology.

The MRI scanners themselves are on the more powerful side. The “3 Tesla” refers to the power of the magnet. A typical hospital MRI scanner operates at 1.5 Tesla or 3 Tesla. There is a 10.5 Tesla MRI unit at the University of Minnesota which is used for the NIH connectome project. So 3 Tesla is a powerful MRI scanner, but no more so than the more powerful typical clinical MRI scanners.

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Jun 27 2017

Sleep

Published by under Neuroscience

poor-sleepSleep is essential and yet many people get insufficient sleep or have poor sleep quality. A recent review gives the following stats:

Population studies show that sleep deprivation and disorders affect many more people worldwide than had been previously thought. A recent study found 20% of 25–45 year-olds slept “90 minutes less than they needed to be in good shape”. Insomnia is the most common specific sleep disorder, with ‘some insomnia problems over the past year’ reported by approximately 30% of adults and chronic insomnia by approximately 10%. Prevalence of obstructive sleep apnoea, characterized by respiratory difficulties during sleep, is also very high with estimates of 9–21% in women and 24–31% in men.

The CDC considers poor sleep a public health problem. As a practicing physician these statistics also match my experience. Poor sleep is comorbid with many neurological conditions I treat, such as migraine. What I find interesting is how many patients I see who are having frequent migraines, they have fatigue, have difficulty with weight control, and are having difficulty with concentration and short-term memory. Further, when asked they report having terrible sleep, and yet they did not volunteer this information or make any connection to their other symptoms.

What this tells me is that people under-appreciate the importance of sleep and the negative consequences of chronic poor sleep. In fact, many patients are initially dismissive of the idea that poor sleep could be a major explanation for their symptoms. They are used to having poor sleep and that is now their normal.

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46 responses so far

Jun 06 2017

The Mechanism of Substitution Heuristic

Published by under Neuroscience

Kahneman-TverskyHuman thinking is complicated. I further find it ironic that we find it so difficult to think about our own thinking. The reason for this is that we are not aware of all of the processes that go into the workings of our own minds. When you think about it, that makes sense. If we had to monitor the mechanisms by which we process information, and then monitor that monitoring, we would use a lot of mental energy in a potentially endless loop of self inspection. This could easily become paralyzing.

So mostly we engage is automatic subconscious problem solving, which uses simplified algorithms to produce decisions which are fast and good enough, absent awareness of what those algorithms are. When we have the luxury for more introspection we can indulge in some analytical thinking as a check on our intuitions.

Added to this, we have made our own world incredibly complex. In a way we have overwhelmed our own intuitions (what psychologists call system 1 thinking). We are fumbling through complex technological and scientific questions involving a world-spanning civilization with a brain evolved for a much smaller and simpler world. This means we need to rely much more heavily on system 2 thinking – careful analytical thinking. This involves metacognition, or thinking about how we think.

Psychologists Kahneman and Tversky have arguably had the most dramatic effect on the study of decision making starting in 1979. They put forward the whole notion of cognitive biases and heuristics, or mental shortcuts we substitute for careful analytical thought.  Continue Reading »

60 responses so far

Jun 01 2017

Confirmation Bias vs Desirability Bias

Published by under Neuroscience

donald-trump-vs-hillary-clinton-top-issuesThe human brain is plagued with cognitive biases – flaws in how we process information that cause our conclusions to deviate from the most accurate description of reality possible with available evidence. This should be obvious to anyone who interacts with other human beings, especially on hot topics such as politics or religion. You will see such biases at work if you peruse the comments to this blog, which is rather a tame corner of the social media world.

Of course most people assume that they are correct and everyone who disagrees with them is crazy, but that is just another bias.

The ruler of all cognitive biases, in my opinion, is confirmation bias. This is a tendency to notice, accept, and remember information which appears to support an existing belief and to ignore, distort, explain away, or forget information which seems to disconfirm an existing belief. This process works undetected in the background to create the powerful illusion that the facts support our beliefs.

If you are not aware of confirmation bias and do not take active steps to avoid it, it will have a dramatic effect on your perception of reality.  Continue Reading »

48 responses so far

May 18 2017

Follow Up on Bem’s Psi Research

telepathyAn interesting article in Slate by Daniel Engber reviews the story of Daryl Bem and his psi “Feeling the Future” research. If you are interested in this sort of thing the entire article is worth a read, but I want to highlight and expand upon the important bits.

For review, in 2011 Bem published a series of 10 experiments in the Journal of Personality and Social Psychology (JPSP). I wrote about the research at the time, and wasn’t impressed. I wrote:

“In the final analysis, this new data from Bem is not convincing at all. It shows very small effects sizes, within the range of noise, and has not been replicated. Further, the statistical analysis used was biased in favor of finding significance, even for questionable data.”

Bem had taken standard social psychology experimental protocols, mostly dealing with priming, and did an interesting thing – he reversed the order of the experiment so that the priming came after the subjects were tested. For example, he would give subjects a memory test and then let some of them study the material. He claimed that the studying had an effect backward in time to allow subjects to perform slightly better.

For experienced skeptics, this was not much of a surprise. When dealing with claims that have a vanishingly small prior probability, you need extraordinary evidence to be taken seriously, and this wasn’t it. We were already very familiar with these kinds of results – if you squint just right there is a teeny tiny effect size. But we already knew that experiments are easy to fudge, even unwittingly, and it would therefore take a lot more to rewrite all the physics textbooks. (What is more likely, that the fundamental nature of reality is not what we thought, or Bem was a little sloppy in his research?) The key (as acknowledged by Bem himself) would be in replication.  Continue Reading »

183 responses so far

Apr 21 2017

Some Brain Science Hype

scalp-EEGTwo recent neuroscience news items in The Independent represent exactly the problem with bad science journalism today and the tendency to overhype incremental studies.

Brain-Machine Interface

Here’s the first:

Device that can literally read your mind invented by scientists. An ‘easily operated’ machine linked to a smartphone could be ready within five years.

Um, no.  I have be writing about this technology for years, because it is genuinely interesting and I think is a technology to watch. Several labs have made significant progress in brain-machine interfaces. The idea is that you read the electrical activity of the brain with either scalp electrodes or brain surface electrodes. Scientists have developed software that interprets the EEG patterns and learns to correlate them with the thoughts or intentions of the subject. The subject, in turn, learns to control their mental activity to affect the EEG output.

Here is where the technology stands: With brain surface electrodes, you get a much greater resolution of EEG activity. The software has progressed to the point that monkeys can control a robotic arm with sufficient subtlety to feed themselves.

With humans we have mostly used scalp electrodes, which have a more blurry signal. Even with these people have learned to control robots or control a cursor on a computer.

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87 responses so far

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