Using our brains to predict intelligence, troubling new Ebola evidence and the link between brains and the microbiome. This week in Abstract Science.

Predicting Intelligence

(Wired Science, 10/12/15, Chelsea Leu)

Being able to map neural connections in the brain is helping researchers figure out why some brains are wired better than others. A study appearing online this week in Nature Neuroscience predicted how well people would do on a cognitive test by analyzing functional MRI scans of 126 people in the Human Connectome Project, which is mapping how areas of the human brain communicate with each other. The individuals performed motor, memory, and intelligence tests, including a pattern completion test that measured abstract reasoning. The researchers found that the more certain regions of the brain were talking to one another, the better the individuals were at processing information quickly and making inferences. Researchers don’t know how these connections are formed and abstract reasoning—what researchers referred to as fluid intelligence—is just one component of intelligence.

Ebola and Semen

(Science, 10/14/15, Kai Kupferschmidt)

Troubling new evidence offers a much clearer picture of a potential after-shock of Ebola. Two studies appearing here and here in the New England Journal of Medicine elucidate what researchers have known for awhile—that fragments of the virus sticks around in semen for months. The first study examined 100 male Ebola survivors from Sierra Leone and found that almost half of the 93 men tested harbored Ebola viral RNA in semen. The likelihood of finding viral RNA declined as time from disease onset increased and detecting viral RNA does not mean that these survivors harbor a virus that’s capable of establishing an infection in a sexual partner, public health scientists cautioned. But in the second study, researchers from Liberia and the United States offered compelling evidence that a 44-year-old woman who was diagnosed in March with Ebola and died a week later may have contracted the virus after having unprotected vaginal intercourse with an Ebola survivor. Studies are ongoing.

Gut Microbes and the Brains

(Nature, 10/14/15, Peter Andrey Smith)

A growing body of data, mostly from animals raised in sterile, germ-free conditions, shows that microbes in the gut influence behavior and can alter brain physiology and neurochemistry. In humans, the data are more limited. Researchers have drawn links between gastrointestinal pathology and psychiatric neurological conditions such as anxiety, depression, autism, schizophrenia and neurodegenerative disorders — but they are just links. So scientists and funders are looking for clarity. Over the past two years, the US has funded seven pilot studies to examine what it calls the ‘microbiome–gut–brain axis’ and, more recently, a separate study examining the gut’s role in cognitive function and stress responses. The European Union is supported a project called MyNewGut, that targets brain development and disorders. Researchers are starting to uncover a vast, varied system in which gut microbes influence the brain through hormones, immune molecules and the specialized metabolites that they produce.

—Compiled by Senior Scientific Writer Regina McEnery