Research roundup. Week of July 10

Culture matters for math. An fMRI study of people doing arithmetic found that the native English speakers were employing different brain regions than the native Chinese speakers to solve the same problems. Evidence, the authors say, for the impact of language on the way the brain processes number.

How social stigma might mark the unborn. More evidence that stress in pregnancy has profound effects on the brain, and hence the behavior, of the baby.

Mind makes world. The parts of the brain active in recollection are the same as those active in hallucinations. No surprise, then, that one fifth of people in a recent study ``remembered'' things they had not seen.

Decisions, decisions. New evidence for the role in decision-making for the Anterior Cingulate Cortex, a region associated with self-monitoring, goal-pursuit and motivation.

Stigma works by disgust. Imaging study suggests that thinking about people in despised groups is associated with the same prefrontal cortex activation that is seen when people are disgusted.

Vox Dei, Vox Boleti? Psilocybin (active ingredient in most psychedelic mushrooms) made experimental volunteers experience feelings of unity with the universe, transcendence of time and space, deep joy -- the effects also found in religious visions. Volunteers and those around them report similar after-effects: changes for the better in the subjects' behavior.

Mr. President, It's a Slam Dunk Overconfidence in war is associated with testosterone, in that men are more prone to this mistake than women. However, the same study reports that T levels within each gender did not correlate with overconfidence.

A Little Feeling Evidence that mice feel empathy: Animals in this study, witnessing another mouse in pain, behaved in the same way as they would have it they had been hurt.