Clever Hans Effect

Summary
Clever Hans was a horse that seemed to be able to perform arithmetic and solve puzzles. However, after a formal 1907 investigation, it was shown that Hans was actually picking up on and responding to subtle audience cues rather than solving problems.

Step right up! Come one, come all! See the amazing wonder horse!
(Photo: Wikimedia)

Commentary
The Clever Hans Effect is important because it exposes how some of our involuntary reactions influence or cue others. This is why there are occasionally problems with police lineups or interrogation of children. It is also why use of double-blind experiments is encouraged.

More on this later.

See Also

• Interrogation Of Children at Institute for Psychological Therapies for a lengthy discussion on the subject.
• Observer-expectancy effect at Wikipedia for the general form of this issue.

First Instinct Fallacy

Summary
Popular advice about taking multiple-choice tests is to stick with your first response because, you're more likely to switch from a correct response to an incorrect one. However, many decades of research seem to suggest otherwise.

Test of knowledge and ability to cope with proofreading errors!
(Quote & Photo: karen_d on Flickr)

Commentary
A study on strategies for multiple choice tests posed the following question to students and teachers:

When taking multiple-choice tests, it is sometimes the case that one answer seems correct at first, but upon further reflection another answer seems correct. As a general rule is it better to stick with your initial "first instinct" - or to change your answer if another choice seems better? In other words, which answer is probably more likely to be correct?

Many students and teachers thought that the first answer you choose is more likely to be correct. Yet, the reality is quite different. Here is an excerpt of the study's results regarding changed answers:

• 51% - wrong to right,
• 25% - right to wrong, and
• 23% - wrong to wrong

(Percentages do not add up to 100% due to rounding errors.)

The study goes on to show that the reason so many people think that sticking with your first answer is better is because of excessive counterfactual thinking. That is, when you change answer from a correct response to an incorrect one, you are more likely to think "if only I hadn't..." which is easier to recall in the future.

See Also

• Counterfactual Thinking and the First Instinct Fallacy for the full text of the study.

Cargo Cults

Summary
A cargo cult is a type of religious practice that may appear in traditional tribal societies in the wake of interaction with technologically advanced cultures. (Source: Wikipedia)

(Video: YouTube)

Commentary
Cargo cults provide an interesting insight into the development of beliefs and rituals. The concept of cargo cults has been extended to include any superficial copy that is disconnected from the underlying workings.

Meta
What are other examples of cargo cults?

See Also

• Detached Lever Fallacy at Less Wrong (formerly Overcoming Bias) for a somewhat related discussion on artificial intelligence systems.
• Tanna: John Frum Day Sulfa Bay at YouTube for part of the annual ceremonies.
• Great Designers Steal at YouTube for a discussion about a similar behavior among designers.

Pentatonic Scale

Summary
The pentatonic scale is a musical scale (i.e. group of notes) with five pitches. It appears in music worldwide and may be related to how humans process music.

Enjoy!

(Video: YouTube)

Placebo Effect

Definition
A placebo is a fake treatment. The placebo effect is the phenomenon whereby patients feel some benefit even from placebo treatments.

Sweet sugar crystals.
(Photo: Wikimedia)

Commentary
Wired has an excellent article on the increasing effectiveness of placebos. It seems that this increase is correlated with the lifting of the ban on direct-to-consumer marketing of drugs by the FDA in 1997.

Other research is focused on determining how placebos work. In one study, researchers were able to see parts of the placebo effect in action in the spine by telling participants that they were trying out a new painkilling cream against a non-painkilling cream (both creams were inactive). While the exact mechanism needs further investigation, this was the first step towards demonstrating the participation of the spine in the placebo effect.

See Also

• Placebos Are Getting More Effective at Wired for the full article.
• Placebos trigger an opioid hit in the brain at New Scientist for a brief discussion of the real effects that placebos have (i.e. generating chemicals in our bodies).
• The Dilute Homeopathy for an example of a very expensive placebo.

fMRI & False Positives

This post is based on a submission by reader Professor Daniel Bitran. Please submit suggestions for posts to metaist.blog@gmail.com.

Definitions
fMRI is a way of measuring blood-flow in the brain or spinal cord and, by extension, neural activity in those areas.

A false positive is the sort of mistake your smoke detector makes when it goes off, but there's no smoke.

Summary
Despite the widespread use of fMRI, a few false positives may result in inaccurate results.

The fMRI is showing neural activity, but the salmon is definitely dead.
(Image: Courtesy of Prefrontal.org)

Commentary
The image above is striking because the false positives seem to show neural activity in a dead salmon's brain. According to researchers at UCLA Santa Barbra, these errors are due to a problem of multiple comparisons.

Imagine we're playing One of These Things is not Like the Others with several tin cans of Atlantic salmons. At first, it's hard to tell which one is not like the others -- there's a bunch of canned salmon. They have similar color, weight, shape, etc. But as we add different ways of comparing the cans (or more cans to compare), we increase the probability that there will be some way in which one of them differs from the rest -- particularly because of small differences, say manufacturing defects.

[Note: Corrections appreciated.] Now imagine we're collecting data for an fMRI. Each each point (called a voxel) is measured several times with certain extreme values discarded. Now we want to figure out which of the voxels is not like the others -- that's because that's where we expect to see differences in blood flow. However, by comparing voxels we're actually comparing multiple measurements of each voxel to multiple measurements of other voxels. This is like adding more ways of comparing the cans. Moreover, because there is a small bit of noise, the measurements for each voxel can be slightly different each time. This is why we occasionally find some difference between neighboring voxels that isn't really there -- it's a false positive. Luckily there are ways of correcting for this sort of error, but unfortunately, it is not applied as frequently as it should.

Meta
What are other examples of widespread errors of multiple comparisons or false positives?

Acknowledgements
Thanks to Craig Bennett of Prefrontal.org for providing a high resolution version of the Atlantic salmon fMRI.

See Also

• Human Brain Mapping 2009 – Presentations at Prefrontal.org for the conference posters & slides.
• Multiple Comparisons with Repeated Measures by David Howell for a lengthy discussion on the subject.
• The Importance of Numeracy

Dihydrogen Monoxide

Summary
Dihydrogen monoxide is the name given to a "colorless and odorless chemical compound" that is pervasive in the environment. It's also a fancy-pants way of saying water.

Dihydrogen monoxide is everywhere!
(Photo: Wikimedia)

Commentary
In 1997, the DHMO hoax was revived by 14-year-old Nathan Zohner who brought it to the public's attention. Zohner petitioned to get DHMO banned as the basis of his science project, titled "How Gullible Are We?" Many people were very gullible, and this hoax occasionally comes back to haunt politicians.

See Also

• MP tries to ban water at The New Zealand Herald for an example of an official who fell for the hoax.
• Dihydrogen Monoxide at Snopes for the email that was circulated on this subject.

Conference: Biological Foundations of Morality

This post is based on a submission by reader Professor Daniel Bitran. Thank you! Please submit suggestions for posts to metaist.blog@gmail.com.

Announcement
From the conference event page:

How does what we are learning about the brain through neuroscience and evolutionary science influence how we ought to think about ethics?

Recent advances in functional neuroimaging have increased scientists' understanding of how our brains process moral decisions. Some thinkers suggest that moral decision making is fundamentally an intuitive or emotional process, and that what we call "reason" is a post-decision making method of justification for actions, not a "higher order" process for making decisions.

If so, the new science challenges the principle of free will, the argument that reason is the foundation of moral decision making, and the importance of understanding intentions before judging responsibility for action. The potential implications for most Western ethical traditions are enormous.

(Formatting added.)

The conference is Thursday-Friday, March 18-19, 2010 at College of the Holy Cross in Worcester, MA.

See Also

• Agenda for the conference.
• About the Speakers at the conference.
• Thinking About Other People's Thoughts

The Mindless Ginkgo

Summary
Ginkgo biloba is a species of tree that is claimed to help prevent memory loss, reverse the effects of dementia, and prevent the onset of Alzheimer's. A recent study showed no such effects.

(Photo: kcm76 on Flickr)

Commentary
The study was the latest product of the National Center for Complementary and Alternative Medicine (NCCAM) -- an organization that uses taxpayer money to design excellent studies to demonstrate the worthlessness of alternative medicines (such as homeopathy).

This particular study is impressive:

[The study is a] randomized, double-blind, placebo-controlled clinical trial of 3069 community-dwelling participants aged 72 to 96 years, conducted in 6 academic medical centers in the United States between 2000 and 2008, with a median follow-up of 6.1 years.

Their conclusion: "Annual rates of decline in z scores did not differ between G. biloba and placebo groups in any domains..." (emphasis added). Which domains did they test? Among them were memory, attention, visuospatial abilities, and language.

See Also

• Ginkgo biloba – No Effect at Science-Based Medicine where Steven Novella points out that some of the effects of supplements (e.g., blood thinning) may pose unnecessary risks (e.g., patients undergoing surgery).

The Dilute Homeopathy

Definition
Homeopathy refers to treatment of symptoms by extremely diluted versions of poisons that are thought to create those symptoms. I'll defer to The Amazing Randi for a nice explanation of why that doesn't make any sense.

(Video: YouTube)

Commentary
My favorite part: "Non habit-forming." Except for the people who have a habit of buying homeopathic "remedies."

See Also

• Mole as a unit of substance.
• Avogadro's constant for the number of atoms or molecules in a mole.

The Perceptive Lintgen

Summary
In 1982, Arthur Lintgen demonstrated conclusively that he is able to identify many classical phonograph records, by simply looking at them.

(Photo: smileitsshan on Flickr)

Commentary
Lintgen never claimed to have any kind of supernatural powers or that he can read individual notes off of records; he just used his vast knowledge of classical music and phonograph construction to determine, for example, out how many movements there are and their relative duration and loudness. His skills are limited to orchestral music from Beethoven onwards.

Meta
When I have told this story in the past (as recently as 12 days ago), I made two errors:

1. I was told that he used his fingernail to play the record very quietly and identified it aurally, rather than visually. This was not the case.
   
   
2. I was told that he was going to be paid the JREF award, but, out of a moral sense, confessed to his true methods. This, too, was not the case; he never claimed to have any paranormal abilities; just abnormal abilities.

Acknowledgements
Two thanks to reader Matthew Garland: once, for knowing the correct version of the story; and again, for making me to look it up so that I could discover my mistakes.
Thanks and thanks!

See Also

• Vinyl Vision at the Skeptic's Dictionary for a longer discussion of Lintgen's methods.
• The Record Reader at Snopes for links to other articles.

The Deceptive Hydrick

Summary
James Hydrick was a performer in the 1980s who claimed to have psychic powers. It turns out he was just blowing on things very carefully.

Caution: Heating packing peanuts may generate static electricity. Or not.
(Photo: cavale on Flickr)

Commentary
Hydrick had a cult following in early 1980s after appearing on several television shows where he demonstrated his "psychic powers" by moving a pencil on the edge of a table, flipping pages of a telephone book, and making dollar bills spin under a fish tank. (Amazing, right?)

James Randi challenged Hydrick on That's My Line hosted by Bob Barker. According to Randi, Hydrick took about 25 minutes to do the page flipping trick, and 45 minutes under Randi's Styrofoam conditions before giving up.

In 1981, journalist (and former magician) Dan Korem managed to first convince Hydrick that he, too, had psychic abilities, and then eventually elicited a confession that Hydrick was just full of air.

The Amazing Randi

Summary
James Randi is a former magician turned skeptic who is known for his challenges of pseudoscience.

(Photo: Wikimedia)

Commentary
James Randi is the founder of the James Randi Educational Foundation (JREF) -- an organization that claims to be "an educational resource on the paranormal, pseudoscientific, and the supernatural." JREF also has a $1 million dollar challenge for concrete evidence, in the form of a mutually-accepted test procedure, of paranormal or supernatural powers. No one has ever won the prize.

More on this later.

Split-brain

Definition
Split-brain is when the two hemispheres of the brain (left & right) are not connected. This is often due to surgery in which the corpus callosum is severed to avoid the spread of epileptic seizures.

(Video: YouTube)

Commentary
One might think that severing all of the connections between the two hemispheres would lead to significant impairment of functioning, yet the two halves continue to communicate-- just outside of the body (e.g., writing, talking, pointing).

There have been cases, however, in which patients behave as though they have two personalities:

Case 1...would sometimes find himself pulling his pants down with one hand and pulling them up with the other. Once, he grabbed his wife with his left hand and shook her violently, with the right hand trying to come to his wife's aid in bringing the left belligerent hand under control. Once, while I was playing horseshoes with the patient in his backyard, he happened to pick up an ax with his left hand. Because it was entirely likely that the more aggressive right hemisphere might be in control, I discretely left the scene-not wanting to be the victim for the test case of which half-brain does society punish or execute. (Gazzaniga 1970, p.107)

I wouldn't want to be the test case either.

Inattentional Blindness

Definition
Inattentional blindness is an explanation for our inability to see certain changes that are usually considered obvious.

(Video: YouTube)

Commentary
Derren Brown has demonstrated this effect with different races, accents, and even genders! While the original studies had a fail rate of 75%, Brown's informal study had about a 50% fail rate.

Meta
Think of all the things we don't notice. Did you notice that in the first video the color of the presenter's shirt changed?

See Also

• Person Swap at YouTube for Derren Brown's version of this experiment.
• What Clown on a Unicycle? Studying Cellphone Distraction at The New York Times for a discussion about a similar phenomenon.

Wireless Electricity

Note: This post contains embedded video which may not appear in your RSS reader. Click here to view the full post.

Summary
Wires are commonly associated with electricity. It is surprising, therefore, that people thought electricity would never be adopted widely if wires were required. Yet it was adopted, but we've only recently started to shed the wires.

(Video: TED)

Commentary
Earlier efforts focused on charging pads such by PureEnergy and SlashPower. The cleverness of MIT's technique is that it combines induction with resonance to achieve power at larger distances. That is, the resonance allows more of the power to be transmitted via induction to the receiver.

Meta
What are other potential uses of wireless electricity?

Electromagnetic Induction

Definition
From Wikipedia:

Electromagnetic induction is the production of voltage across a conductor situated in a changing magnetic field or a conductor moving through a stationary magnetic field.

In other words, magic.

One toroid to rule them all. Or not.
(Photo: Wikimedia)

Commentary
Induction is the principle behind generating electricity, most electrical motors, and some "smart" traffic lights. It's also how that little bit of foil gets attached to pill bottles and other containers.

More on this later.

See Also

• Concepts in Science: Electromagnetic Induction for an 80's video that's long, but informative.

Resonance

Definition
Resonance refers to a tendency of a system to oscillate more at certain frequencies than at others. Those frequencies are known as resonant frequencies.

(Photo: stevenduong on Flickr)

Commentary
An excellent example of acoustic resonance is shattering a wine glass with sound. Here's a quick explanation as to why the glass shatters:

1. The sound is being generated by a speaker. The speaker works by moving a small cone back and forth generating the appropriate frequency. You can sometimes see the movements.
   
   
2. Many frequencies make the glass vibrate, but only a handful make it vibrate so much that it cannot stay together. Those frequencies are the resonant frequencies-- they make the glass vibrate (i.e. oscillate) much more than the other frequencies.
   
   
3. Since the glass is insufficiently elastic, it shatters.

Meta
What other resonant systems have you encountered?

Feedback Friday: January 2010

Summary
The Metaist continues to show consistent readership. The blog is drifting towards discussions about human behavior, psychology (especially cognitive biases), and economics, plus a dash of technology.

Word clouds. Expect to see more of them in the future.
(Image: Woordle)

Feedback
Much of the source material for this blog comes from discussions with readers. I occasionally recall an interesting study or video I saw the illustrates an aspect of human behavior, an interesting business maxim, or explains how something works.

So my question this month is: What is some human behavior you always wanted explained?