The "Mind Matters" feature on the Scientific American blog has a commentary up by psychologist Sian Beilock. The commentary reviews last year's research that showed assigning a simple self-esteem-building essay can have a large impact on testing performance for minority students.
What I found much more interesting was Beilock's work on performance under pressure, when people are liable to "choke". I found a University of Chicago-sponsored description:
Her own experience as a lacrosse player at the University of California, San Diego, fueled Beilock's first questions about performance. To answer them, she retired her lacrosse stick and hit the putting green. Like riding a bike, Beilock says, putting becomes largely automatic once mastered, making it a "nice test bed" to gauge pressure's impact on golfers. When skilled players -- undergraduate subjects with two or more years of varsity golf experience or a PGA handicap lower than eight -- were asked to sink the ball while simultaneously identifying a specific word from a tape recording, putting ability came through unscathed, despite extra demands on concentration. Force these same experts, however, to think about their skill in a way they normally don't, such as focusing on club-swing distance or elbow position, and performance suffers. The extra attention, explains Beilock, is a common side effect of pressure situations that disrupts the flow of a well-honed activity, throwing off even the most talented individuals.
"Automatic" performance has long been fodder for intro psychology classes; it's a phenomenon that everybody can recognize. But there is a difference between the kind of automatic performance examined here -- a golf swing -- and automatic performance during other activities, like driving a car.
Driving is a long, continued activity that can occur with minimal conscious attention, at least in good conditions. But take a driver and distract him with a cell phone (or some kind of word-identifying task), and performance degrades.
So why don't the golfers experience the same performance degradation? The answer is that their "automatic" performance is in the form of highly practiced short action sequences. These short action sequences, by the way, are the kind of thing handled in the posterior part of Broca's area and the adjacent premotor cortex (link). The practiced actions do not degrade upon distraction, because the distraction does not interfere in any way with planning the sequence -- the sequence is already planned. But ask the golfer to "think about" his swing, and the sequence is brought back into question.
This kind of planned and practiced action sequence is fundamental to human imitation. If you can't parse a set of actions into some kind of sequence, you can't imitate it. This is the kind of imitation that other primates really aren't very good at. It's also probably fundamental to stone tool manufacture, since the fine control of knapping action depends on maintaining such short action sequences, and formulating longer strategies for segmenting them into a reduction sequence.
Other skills work in the opposite way. While a math whiz might perform calculations more quickly than a less-qualified classmate, successful execution still demands the experts dedicated focus. In contrast to a sensorimotor task like putting, many cognitive tasks call upon reserves of "working memory." It's the same type of short-term brain activity used to remember a number from the Yellow Pages long enough to make the call, and retention varies from person to person. In a low-stress situation -- Beilocks subjects were told they were doing practice questions -- individuals who showed greater working-memory capacity did better on a challenging math task than lower-working-memory subjects. When pressure kicked in, however, these high-performers suffered the sharpest performance plunge. The discrepancy, Beilock says, suggests that individuals with high working memory may rely on complicated problem-solving techniques that naturally require more working-memory capacity than available under pressure. When anxiety begins to crowd that mental space, skilled individuals may not have enough room left over to solve the equation as quickly or successfully as usual.
Any of my students reading this after this week's exam should know that I sympathize!
This idea is very clever; I wonder if it isn't too clever. The hypothesis is that a larger working memory usually facilitiates a more complicated problem-solving method, which is more easily "crashed" by working memory "crowding". It's not obvious why stress should have this effect, though, which would seem to be highly maladaptive. Unless, "problem-solving" abilities evolved under a different context than "high-stress" situations. Maybe it is a very unusual strain of person who can think well under pressure -- or maybe an insensitivity to pressure is the real key?
Well, anyway, it seems clear that people really don't think as well under pressure, which is its own kind of distractor. And those little questions that give rise to self-doubt are some of the most powerful distractors, because they interfere with the process they reference.