Neural evidence for sudden insight

This is another demonstration of stereotype threat, which is also a nice demonstration of the contextual nature of intelligence. The study involved 70 volunteers (average age 25; range 18-49), who were put in groups of 5. Participants were given a baseline IQ test, on which they were given no feedback. The group then participated in a group IQ test, in which 92 multi-choice questions were presented on a monitor (both individual and group tests were taken from Cattell’s culture fair intelligence test). Each question appeared to each person at the same time, for a pre-determined time.

I’ve reported before on evidence that young children do better on motor tasks when they talk to themselves out loud, and learn better when they explain things to themselves or (even better) their mother. A new study extends those findings to children with autism.

One survey of nearly 200 undergraduate college students who were not living with a parent or legal guardian found that 55% reported getting less than seven hours sleep. This is consistent with other surveys. The latest study confirms such a result, but also finds that students tend to think their sleep quality is better than it is (70% of students surveyed described their sleep as "fairly good" or better).

I always like studies about embodied cognition — that is, about how what we do physically affects how we think. Here are a couple of new ones.

It has been difficult to train individuals in such a way that they improve in general skills rather than the specific ones used in training. However, recently some success has been achieved using what is called an “n-back” task, a task that involves presenting a series of visual and/or auditory cues to a subject and asking the subject to respond if that cue has occurred, to start with, one time back. If the subject scores well, the number of times back is increased each round.

Whether IQ tests really measure intelligence has long been debated. A new study provides evidence that motivation is also a factor.

Meta-analysis of 46 studies where monetary incentives were used in IQ testing has revealed a large effect of reward on IQ score. The average effect was equivalent to nearly 10 IQ points, with the size of the effect depending on the size of the reward. Rewards greater than $10 produced increases roughly equivalent to 20 IQ points. The effects of incentives were greater for individuals with lower baseline IQ scores.

Most memory research has concerned itself with learning over time, but many memories, of course, become fixed in our mind after only one experience. The mechanism by which we acquire knowledge from single events is not well understood, but a new study sheds some light on it.

In the first of three experiments, 132 students were found to gesture more often when they had difficulties solving mental rotation problems. In the second experiment, 22 students were encouraged to gesture, while 22 were given no such encouragement, and a further 22 were told to sit on their hands to prevent gesturing. Those encouraged to gesture solved more mental rotation problems.

In a recent study, volunteers were asked to solve a problem known as the Tower of Hanoi, a game in which you have to move stacked disks from one peg to another. Later, they were asked to explain how they did it (very difficult to do without using your hands.) The volunteers then played the game again. But for some of them, the weight of the disks had secretly reversed, so that the smallest disk was now the heaviest and needed two hands.

A link between positive mood and creativity is supported by a study in which 87 students were put into different moods (using music and video clips) and then given a category learning task to do (classifying sets of pictures with visually complex patterns). There were two category tasks: one involved classification on the basis of a rule that could be verbalized; the other was based on a multi-dimensional pattern that could not easily be verbalized.