Damage to Brain's Memory Center May Alter Moral Decision-Making
It's a classic moral dilemma: You see a train speeding toward five people tied to the tracks. If you do nothing, they will die. But if you pull a lever, you can divert the train to another track that has only one person tied to it. What do you do? Making a complex moral decision like this engages an area at the front of the brain called the ventromedial prefrontal cortex, or vmPFC. Previous studies have found that people with damage to the vmPFC make more utilitarian decisions — they're more likely to pull the lever. In a new study, researchers find people with damage to the hippocampus — an area of the brain critical for learning and memory — are more likely to do the opposite. They reject choices that harm even one person and show heightened emotional arousal compared to healthy adults. The results reveal how these two closely connected areas of the brain contribute to moral decision-making.
Corresponding author: Eleanor Maguire
Changes in Brain Waves May Underlie Language Specialization in Babies
In the first few months of life, babies process the distinct sounds of all languages in a similar way. By their first birthday, babies are experts at discriminating the sounds of their native language, but this comes at the cost of a diminished ability to process the sounds of other languages. In a new study, researchers trace the developmental trajectory of this phenomenon, which begins to emerge around six months of age, and they find it depends on the interplay between two specific types of brain waves. The findings shed light on the rhythmic neural activity underlying language specialization in the first year of life.
Corresponding author: Silvia Ortiz-Mantilla
Aberrant Immune Activity May Link Alzheimer's and Depression
A wealth of evidence links Alzheimer's disease and depression — by some estimates, up to 90 percent of Alzheimer's patients may have a mood disorder. Recently, researchers found the misfolded proteins that accumulate in the brains of those with Alzheimer's can induce symptoms of depression in mice, and in a new study, the same researchers discover how. The team finds amyloid-beta oligomers activate innate immune cells and decrease the amount of the neurotransmitter serotonin in the mouse brain, which both contribute to depressive-like behavior. The results reveal a mechanism linking Alzheimer's and depression, and may pave the way for new therapies for both disorders.
Corresponding author: Sergio Ferreira
The Journal of Neuroscience is published by the Society for Neuroscience, an organization of nearly 38,000 basic scientists and clinicians who study the brain and nervous system.
Check out these newsworthy studies from the November 30, 2016, issue of JNeurosci. Media interested in obtaining the full text of the studies should contact [email protected] .
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