The new Diagnostics and Statistical Manual, DSM-V, is out. Not surprisingly, it has sparked some controversy. Psychiatry deniers are proclaiming that this is the collapse of the mental-illness fraud (I believe reports of the death of psychiatry are exaggerated).

What the DSM-V does represent, to some degree, is an attempt to advance psychiatry to the next stage of our understanding of illness. It seems that we are not quite ready for this step in psychiatry, but the effort is sincere and interesting.

For background, the DSM (now in the fifth edition) is essentially a list of official psychiatric diagnoses, based upon clinical criteria. For mental illness and disorders we mostly lack clear biological markers or pathology, and so we have had to make do with clinical descriptions – lists of signs and symptoms. This is very much a descriptive phase of scientific understanding.

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Expectation bias cuts both ways, for positive and negative expectations. Expectation bias, the tendency to perceive and accept data that reinforces your expectation, is one of the many contributors to placebo effects (the illusion of a positive benefit that derive from something other than an active treatment). It is also, however, part of nocebo effects  (the illusion of negative side effects from something other than active treatment).

Expectation bias can be powerful enough in some people to lead not only to the perception of a benefit or side effect but to a frank delusion. When this happens on a large scale, that can lead to a mass delusion. There are many episode that demonstrate this effect, but now there is also a controlled experiment that also confirms it.

A recent study looked at sham exposure to wifi signals in 147 subjects. They were first exposed to either a documentary about the dangers of wifi, or to a documentary about internet security. A total of 54% of the subjects experienced

“…agitation and anxiety, loss of concentration or tingling in their fingers, arms, legs, and feet. Two participants left the study prematurely because their symptoms were so severe that they no longer wanted to be exposed to the assumed radiation.”

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I gave a seminar recently to science teachers and the topic of whether or not there is a lunar effect came up. I was not surprised to find that 80% of them believed that emergency rooms and police stations are more busy during a full moon. I was also not surprised, but only because I have been there before, that they were highly resistant to my claim that the scientific evidence shows that there is no such effect.

Several questions emerge from the notion that the phases of the moon affect human behavior: what is the plausibility of such a claim, is there actually such an effect, and if not why do so many people believe that there is?

Plausibility

One of two justifications are commonly given for how the moon might influence human behavior. The moon basically has two physical effects on our environment – gravity and light. Astrological influences are not worth further discussion in this article, and I rarely hear that as a justification from the general public in any case.

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It should not come as a surprise to anyone that, as a strict materialist, I accept the standard neuroscientific model of consciousness. That means that everything we think, feel, remember, and do is a function of the brain. This includes the emotion of empathy.

We are not empathic because it makes sense to be empathic – meaning that most humans don’t simply reason their way to empathy. Nor do we simply learn empathy (although brain development is an interactive process with the environment, so we can’t rule out environmental influences). For the most part, we have empathy because our brains are wired with empathy as a specific function.

Like every function of the body you can think of, if it is not essential for survival then some subset of the human population likely has a disorder or even absence of this function. We recognize the absence of empathy as the disorder, psychopathy.

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Fans of science fiction are likely familiar with the continuity problem. You get beamed aboard the Enterprise by the transporter and everything seems to work perfectly. On Earth you are disassembled into your most fundamental particles in order to capture all of the information necessary to then recreate you in your exact state aboard the Enterprise.

The new you aboard the Enterprise is you in every detail, including your stream of consciousness – the thoughts you were having at the moment of beaming. But is it really you? Isn’t it more accurate to say that you were destroyed on Earth and are now dead, and a copy of you was created on board the ship? That is the continuity problem.

I have discussed this issues several times on this blog and on the SGU, including on this week’s show. The topic always provokes lively discussion. One common observation that I hear in response is that the continuity problem is not really a problem at all – we lose continuity every night when we sleep, and we are not worried about it when we wake up.

I have always found this analogy to be puzzling. It seems so transparently false, why is it so commonly used? When you sleep there is absolute continuity, it has no analogy to the transporter situation.

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Imagine that one of your limbs did not feel as if it belonged to you or was a natural part of your body. In a weird way the “extra” limb makes you feel incomplete, less than your whole self. The limb functions, you can feel it, and its completely healthy – it’s just not yours. It is a constant irritant. Eventually you become obsessed with the idea of amputating the limb. You fantasize about amputation and imagine yourself without the offensive body part.

This desire to amputate a healthy limb was described and named apotemnophilia  by Money in 1977. It has recently been renamed Body Integrity Identity Disorder (BIID). This is a rare and interesting disorder – at first it was thought to be psychological, but it is more likely to be a neurological disorder.

Recent fMRI evidence suggests that people with BIID have decreased activation of their right superior parietal lobe when the “extra” limb is touched. This likely relates to the brain’s internal map or schema of the body.

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We are seeing the beginning of technology to interface computers and brains. I have been writing about brain-machine-interface (BMI) technology, and brain-machine-brain interface technology. Now we have a report of brain to brain communication, which is currently as close as we can come to telepathy.

Actually, the technology is – brain to machine to another machine and then to another brain – technology. Imagine having a computer chip implanted in your brain that can read your brain activity. This information is then transferred to a computer chip implanted in someone else’s brain, who can then access that information.

If this exchange were happening in real time through wireless transfer with sufficient resolution, that would essentially be telepathy.

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It is tempting to make arguments about how and why particular aspects of human psychology evolved. I will not be getting into an evolutionary psychology discussion in this post, I will just say I find such arguments offer a plausible framework for understanding human psychology, regardless of whether you think they can be scientifically tested.

A recent example is a paper by researchers at McMaster University. The title of their press release  reads: It’s in the cards: Human evolution influences gamblers’ decisions, study shows. 

The study actually says nothing about human evolution. It simply demonstrates an aspect of human behavior – the evolutionary explanation is pure speculation, not tested or demonstrated in the study itself.

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The human brain is perhaps the most complex machine that we have investigated, especially the higher cognitive functions. Psychologists have been working for decades to untangle the complex set of genetic, neurological, environmental, and situational factors that ultimately result in human behavior, with a great deal of success.

There are a few standouts – seminal experiments that not only demonstrate something interesting about human nature, but also create an entire paradigm of psychological studies that other researcher replicate with various modifications. One such such is the marshmallow test, first conducted by a team lead by Walter Mischel then at Stanford University.

The first series of such studies Mischel published in 1972 took a group of preschoolers and offered them their choice of three rewards: a cookie, a pretzel, or a marshmallow. The researcher then told the children that they could eat their treat whenever they want, but if they hold off the researcher would return with an additional treat. The study was a test of self-control and the ability to delay gratification.

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Take a look at the picture just below the fold. Pretend you are a radiologist and your job is to find anything strange or abnormal on the scan. You are specifically looking for signs of cancer, but you need to find anything abnormal.

Done? OK – did you see the gorilla in the right upper corner of the scan? If you didn’t, don’t feel bad. Neither did 83% of radiologists studied, according to Trafton Drew who ran the study (which has not yet been published).

Readers of this and other skeptical blogs are likely familiar with this classic video of students tossing basketballs to each other  (if not, take and look before reading further). About half of the people viewing this video miss the obvious gorilla strolling across the screen. This is a phenomenon known as inattentional blindness – when our attention is focused on a specific task we are likely to miss information that is extraneous to that task, even if it is in our visual field and otherwise obvious.

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