? Not that the eyes aren’t impressive, because they are. The eyes are so complex that they’re often cited (not a pun) by creationists and others opposed to evolution as clear proof that natural selection isn’t real; the eye is so intricate it couldn’t just “happen” and therefore must be the work of a powerful creator. But if you truly look at the workings of the eye, then this creator must have designed the eye on a Friday afternoon, or while hung over on the morning shift, because a lot of it doesn’t make much sense.
§ Modern camera and computing technology means it’s much easier (and considerably less uncomfortable) to track eye movements. Some marketing companies have even used eye scanners mounted on trolleys to observe what customers are looking at in stores. Before this, head-mounted laser trackers were used. Science is so advanced these days that lasers are now old-fashioned. This is a cool thing to realize.
? For the record, some people claim that they’ve had eye surgery and their eye was “taken out” and left dangling on their cheek at the end of the optic nerve, like in a Tex Avery cartoon. This is impossible; there is some give in the optic nerve, but certainly not enough to support the eye like a grotesque conker on a string. Eye surgery usually involves pulling the eyelids back, holding the eye in place with clamps, and numbing injections, so it feels weird from the patient’s perspective. But the firmness of the eye socket and fragility of the optic nerve means popping the eye out would effectively destroy it, which isn’t a great move for an ophthalmic surgeon.
# Exactly how we “focus” aural attention is unclear. We don’t swivel our ears towards interesting sounds. One possibility comes from a study by Edward Chang and Nima Mesgarani of the University of California, San Francisco, who looked at the auditory cortex of three epilepsy patients who had electrodes implanted in the relevant regions (to record and help localize seizure activity, not for fun or anything).13 When asked to focus on a specific audio stream out of two or more heard at once, only the one being paid attention to produced any activity in the auditory cortex. The brain somehow suppresses any competing information, allowing full attention to be paid to the voice being listened to. This suggests your brain really can “tune someone out,” like when they won’t stop droning on about their tedious hedgehog-spotting hobby.
6
Personality: a testing concept
The complex and confusing properties of personality
Personality. Everybody has one (except maybe those who enter politics). But what is a personality? Roughly, it’s a combination of an individual’s tendencies, beliefs, ways of thinking and behaving. It’s clearly some “higher” function, a combination of all the sophisticated and advanced mental processes humans seem uniquely capable of thanks to our gargantuan brains. But, surprisingly, many think personality doesn’t come from the brain at all.
Historically, people believed in dualism; the idea that the mind and body are separate. The brain, whatever you think of it, is still part of the body; it’s a physical organ. Dualists would argue that the more intangible, philosophical elements of a person (beliefs, attitudes, loves and hates) are held within the mind, or “spirit,” or whatever term is given to the immaterial elements of a person.
Then, on September 13, 1848, as a result of an unplanned explosion, railroad worker Phineas Gage had his brain impaled by an iron rod more than 3 feet long. It entered his skull just under his left eye, passed right through his left frontal lobe, and exited via the top of his skull. It landed some 80 feet away. The force propelling the rod was so great that a human head offered as much resistance as a net curtain. To clarify, this was not a paper cut.
You’d be forgiven for assuming this would have been fatal. Even today, “huge iron rod right through the head” sounds like a 100-percent-lethal injury. And this happened in the mid-1800s, when stubbing your toe usually meant a grim death from gangrene. But, no, Gage survived, and lived another twelve years.
Part of the explanation for this is that the iron pole was very smooth and pointed, and traveling at such a speed that the wound was surprisingly precise and “clean.” It destroyed almost all the frontal lobe in the left hemisphere of his brain but the brain has impressive levels of redundancy built into it, so the other hemisphere picked up the slack and provided normal functioning. Gage has become iconic in the fields of psychology and neuroscience, as his injury supposedly resulted in a sudden and drastic change in his personality. From a mild-mannered and hardworking sort, he became irresponsible, ill-tempered, foul-mouthed, and even psychotic. “Dualism” had a fight on its hands as this discovery firmly established the idea that the workings of the brain are responsible for a person’s personality.
However, reports of Gage’s changes vary wildly, and towards the end of his life, he was employed long-term as a stagecoach driver, a job with a lot of responsibility and public interaction, so even if he did experience disruptive personality changes he must have got better again. But the extreme claims persist, largely because contemporary psychologists (at the time, a career dominated by self-aggrandizing wealthy white men, whereas now it’s . . . actually, never mind) leapt on Gage’s case as an opportunity to promote their own theories about how the brain worked; and if that meant attributing things that never happened to a lowly railway worker, what of it? This was the nineteenth century, he wasn’t exactly going to find out via Facebook. Most of the extreme claims about his personality changes were seemingly made after his death, so it was practically impossible to refute them.
But even if people were dedicated enough to investigate the actual personality or intellectual changes Gage had experienced, how would they do this? IQ tests were half a century away, and that’s just one possible property that might have been affected. So Gage’s case led to two persistent realizations about personality: it’s a product of the brain, and it’s a real pain to measure in a valid, objective manner.
E. Jerry Phares and William Chaplin, in their 2009 book Introduction to Personality,1 came up with a definition of personality that most psychologists would be willing to accept: “Personality is that pattern of characteristic thoughts, feelings, and behaviors that distinguishes one person from another and that persists over time and situations.”
In the next few sections, we’re going to look at a few fascinating aspects—the approaches used to measure personality, what it is that makes people angry, how they end up compelled to do certain things, and that universal arbiter of a good personality, sense of humor.
Nothing personal
(The questionable use of personality tests)