In brief from the AAAS

Christian Jarrett reports from the 177th Annual Meeting of the American Association for the Advancement of Science, Washington

Criminality has its roots in abnormal brain development, according to British psychologist Adrian Raine (University of Pennsylvania). He reported that three-year-old children who demonstrated poor fear conditioning - a marker for amygdala function - were at increased risk of criminal behaviour 20 years later. This tallies with adult research showing that people diagnosed as psychopathic have reduced amygdala volume. 'The seeds of sin are sown quite early in life,' Raine said. 'The time is going to come when we are going to be able to predict reasonably well which individuals at a modest age, say eight to 10 years old, are predicated to become criminal offenders.'

A multidisciplinary seminar explored the causes of stuttering - a timely topic in light of the success of the film The King's Speech. Half of all cases have a family history of stammering, and geneticist Dennis Drayna (NIH) highlighted his work showing that stuttering-related genes are involved in cell metabolism. Lu De Nil (University of Toronto) described brain differences in those who stutter, including over-reactivity in neural regions associated with motor control. And Anne Smith at Purdue University has studied four- and five-year-olds who stutter, finding that they sometimes also find it difficult to clap a beat.

The use of virtual reality (VR) to help understand our sense of body ownership has been combined with EEG in one of the first studies of its kind. A team led by Olaf Blanke at the École Polytechnique Fédérale de Lausanne (EPFL) showed previously that it's possible to trick people into feeling ownership of a stationary digital avatar. This is done by touching the person's real body in synchrony with a touch to the avatar, viewed through a VR headset. Blanke's new research provoked a sense of ownership over moving avatars, and EEG revealed a network of brain areas involved, including the temporal parietal cortex, the medial prefrontal cortex and the visual cortex.

A study of hundreds of patients diagnosed with Alzheimer's disease found that those who spoke a second language for most of their lives tended to develop the disease later in life, compared with their monolingual peers. 'We don't believe bilingualism prevents Alzheimer's disease,' psychologist Ellen Bialystok (York University, Canada) told the AAAS Science Update radio show. 'What we're saying is, people who have been bilingual have more reserve, they have more resources to continue functioning at a high level in spite of the disease progressing in their brains.'

Macaque monkeys, which originate from the Old World (Africa, Asia and Europe), have the human-like insight of knowing what they don't know. Professor John David Smith (State University of New York at Buffalo) and Michael Beran (Georgia State University) tasked the monkeys with deciding whether arrays of pixels were dense or sparse. When the choice was too tricky the monkeys took a third option - selecting a question mark - thus skipping to the next question and reducing the time they'd have to wait for another chance to earn a reward. In contrast, New World capuchin monkeys (from central and south America) never used the 'don't know' option. The finding provides clues about the evolution of meta - cognition