Mind Hacks

This is an excerpt from quite possibly the geekiest forensic pathology article I have ever read. Three pathologists discuss the physics of how a Mexican coin ended up in the brain of a dead shooting victim.

They speculate he may have been holding it in his hand while shielding his head and the bullet impacted on the coin and both ended up deep in the brain. Oh, but with maths.

The images on the left are an artist’s reconstruction of the position of the man when shot and the path of the bullet, and a photo of the coin in the dead man’s brain.

Items that become accessory or secondary projectiles usually possess a minimal amount of energy, producing superficial or insignificant wounds. The secondary projectile in this case, a coin, gained sufficient kinetic energy to penetrate the scalp, skull, and brain. We believe the coin was being held by the decedent in his left hand next to his head at the time of the shooting. The bullet passed through the hand, producing the described injury and picking up the coin as a secondary projectile before entering the head.

The coin, a 1970 Mexican 50-centavo piece, was 25 mm in diameter with a weight of 6.4 g. In comparison, the diameter of a 1970 U.S. quarter dollar coin is 24.3 mm with a weight of 5.6 g. Both coins contain a mixture of copper and nickel, and the U.S. coin is coated with silver. The mixture of nickel and copper is relatively soft and permits deformation, as seen in this case. The primary projectile, a .380-caliber automatic Colt pistol 9- √ó 17-mm Winchester Silvertip bullet, weighs 5.1 g, with a rated muzzle velocity of 304 m/second (1000 feet/second). The mass of the conjoined projectile more than doubled with addition of the coin, yet retained sufficient velocity to produce the described lethal injury.

We attempted to see if this would be theoretically possible using some simple physical principles. Under ideal conditions, this event represents a form of an inelastic collision. We assumed that there was conservation of momentum between the oncoming bullet and the departing conjoined bullet-coin mass that subsequently penetrated the skull and brain. If momentum is conserved during this collision, then the mass of the bullet multiplied by its velocity would equal the mass of the conjoined bullet and 50-centavo coin multiplied by their departing velocity. The velocity of the bullet just prior to striking the coin is unknown and could not be determined.

For our calculations, we used the known muzzle velocity of this ammunition, understanding the limitations of such an assumption. We also calculated the kinetic energy and momentum of the oncoming bullet and exiting conjoined bullet-coin before and after collision. The results indicate two things: as expected in an inelastic collision, the kinetic energy of the conjoined bullet and coin is much less than that of the oncoming bullet, and the velocity of the conjoined projectile drops by greater than a factor of two. No doubt some of this loss in kinetic energy resulted from the energy expended in deforming the Mexican coin. The calculated loss in velocity of the bullet postcollision slows this projectile (i.e., the conjoined bullet/coin) to <150 meters per second (<450 feet/second). However, this velocity would still be well in excess of the minimal velocity needed to penetrate skin and bone, which has been reported to be about 66 meters per second (200 feet/second).

Forensic pathology has this morbid deadpan geekiness about it which just makes it so interesting to read.

You can just see them in the pathology room, arguing about what happened and sketching calculations on the back of envelopes.

Link to PubMed entry for article.

In the wake of the Nature survey that found that 20% of scientists admit to using brain enhancing drugs, Wired has just published an article detailing what drugs their scientist readers use to keep on keepin’ on.

Although the drugs issue is obviously the headline-grabber, the publication also has a great feature on cognitive enhancement that largely covers tips, tricks and techniques to boost your mental skills that aren’t drug-related.

The article itself is anecdotally interesting, but has a curious tone throughout:

Surprisingly large numbers of people appear to be using brain-enhancing drugs to work harder, longer and better. They’re popping pills normally prescribed for narcolepsy or attention-deficit disorder to improve their performance at work and school.

“We aren’t the teen clubbers popping uppers to get through a hard day running a cash register after binge drinking,” wrote a Ph.D. research scientist who regularly takes a wakefulness drug called Provigil, normally prescribed for narcolepsy. “We are responsible humans.”

Whenever people talk about using drugs, they’re always keen to distance themselves from that sort of drug user. You know, the ones that aren’t responsible.

This belies the fact that most people use most drugs with few problems. Even teen clubbers popping uppers.

While all drugs have risks and illicit street drugs increase the health risks and definitely have an impact on body and brain function, it’s only a minority of drug users who have problems that interfere with their daily lives.

For example, a recent study found that 4% of Australian workers use the (fairly nasty) drug methamphetamine. The figure rises to over 11% for 18-29 year olds. That more than 1 in 10.

While the study found that using methamphetamine significantly increases chances of a range of health problems, it’s still the minority of users that report significant problems. This is the typical pattern for studies on drug use.

In other words, drugs are bad for you but most people manage the risks. A small minority, of course, don’t, and die instantly or suffer long-term consequences.

The benefit and using and abusing prescription drugs for ‘brain doping’ is largely in the fact that you can be sure of the purity of the product and that probably (depending on how you acquire them) you’re not funding a vicious criminal network.

At the end of the day though, the process is the same, whether you’re using legal drugs, illegal drugs, for recreation or for performance.

Just make sure you’re educated about the risks and know the consequences. Just like everything else in life.

Link to Wired.com Readers’ Brain-Enhancing Drug Regimens.
Link to Wired ‘Give Your Intellect a Boost’ techniques.

This month’s Trends in Cognitive Sciences has a fantastic review article on the neuroscience of meditation – focusing on how the contemplative practice alters and sharpens the brain’s attention systems.

The full article is available online as a pdf, and discusses what cognitive science studies have told us about the short and long-term impact of meditation on the mind and brain.

Meditation is now being quite extensively studied by cognitive science owing to the clear effects it has on the brain, and on the increasing evidence for its benefit in mental health.

A recent review of ‘mindfulness’ meditation-based therapy found that although research is in its early stages and not all possibilities have been ruled out, there’s good evidence from the existing RCTs that it’s particularly good in preventing relapse in severe depression.

The Trends article, which largely focused on the neuroscience research, makes the distinction between two types of meditation: ‘focused attention’ meditation – that involves focusing on a particular thing and refocusing if you become distracted by thoughts or sensations; and ‘open monitoring’ meditation which involves nonreactively monitoring the content of experience and acting as almost a detached observer to feelings and mental events.

This is an excerpt where the authors discuss the experimental evidence for the long-term ‘open monitoring’ or OM meditation:

Long-term practice of OM meditation is also thought to result in enduring changes in mental and brain function. Specifically, because OM meditation fosters nonreactive awareness of the stream of experience without deliberate selection of a primary object, intensive practice can be expected to reduce the elaborative thinking that would be stimulated by evaluating or interpreting a selected object. In line with this idea, Slagter et al. recently found that three months of intensive OM meditation reduced elaborative processing of the first of two target stimuli (T1 and T2) presented in a rapid stream of distracters…

Because participants were not engaged in formal meditation during task performance, these results provide support for the idea that one effect of an intensive training in OM meditation might be reduction in the propensity to ‘get stuck’ on a target, as reflected in less elaborate stimulus processing and the development of efficient mechanisms to engage and then disengage from target stimuli in response to task demands. From the description in Box 2,we anticipate a similar improvement in the capacity to disengage from aversive emotional stimuli following OM training, enabling greater emotional flexibility.

Moreover, the article includes many other studies that have reported interesting effects. For example, highly experienced focused attention meditators need minimal effort to sustain attentional focus, while even short courses on meditation can improve attention and decrease stress.

Most of the techniques are taken from Buddhist meditation practices and I’m sure Buddhists are cracking a wry smile as cognitive science is just starting to catch on to what they’ve been noting for thousands of years.

As for the neuroscience, I’m sure the remarkably science-savvy Dalai Lama is fascinated as he’s held a number of conferences with leading researchers to discuss the the intersection between Buddhist practice and cognitive science.

Link to abstract of article.
pdf of full-text.