Your growing, shrinking brain
Researchers have created a set of reference growth charts for human brain development, showing how brains expand quickly early in life and then shrink slowly with age.
The charts, reported in Nature, were generated from a vast collection of brain scans made using magnetic resonance imaging. Because brain structure varies significantly from person to person, the researchers had to aggregate a large number of scans to create an authoritative set of growth charts. The data on ventricular volume (the amount of cerebrospinal fluid in the brain) is a particular surprise: scientists knew it increases with age, because it is typically associated with brain atrophy, but not how rapidly it tends to grow in late adulthood. A News story explains more.
Schizophrenia’s discovery gap
This graph represents two efforts to identify genetic variants associated with schizophrenia – and the ‘discovery gap’ where future variants might be found.
There has long been debate about whether the genetic component of complex disorders, such as schizophrenia, is attributable mainly to rare or common DNA variants. Two studies in Nature provide evidence for key roles of both types of variant. The first study used genome-wide association studies to identify 342 common genetic variants that are each associated with a slightly increased risk of developing the disorder (blue). The second study used genetic sequencing to identify ten genes that harbor rare, protein-truncating variants with large effects on disease risk (red). The two studies suggest that rare and common risk variants might often affect the same biological mechanisms.
As a News & Views article explains, an approach that combines genome-wide association studies and sequencing could help fill the discovery gap between these two classes of risk variant, providing further insights into the biological pathways that can lead to schizophrenia.
Laugh, then cite
Brace yourself for a wave of puns in academic papers. This chart shows the results of a study suggesting that papers with funny titles receive more citations.
Researchers asked volunteers to score the titles of 2,439 papers in 9 ecology and evolution journals according to how amusing they were, from 0 (completely serious) to 6 (extremely funny). The team then looked for a link between the papers’ humor scores and the number of citations they had received, including self-citations by their own authors.
Papers with funny titles were cited slightly less often than their more serious counterparts (left) and were also self-cited less (middle). After controlling for self-citations as a measure of a paper’s importance, the researchers found that articles with funny titles are in fact cited more than those with serious titles (right). But as a News story reports, some researchers have questioned the conclusions of the study, which has so far been posted as a preprint and has not yet been peer reviewed.