When jurors sentencing convicted criminals are instructed to weigh not only facts but also tricky emotional factors, they rely on parts of the brain associated with sympathy and making moral judgments, according to a new paper by a team of neuroscientists. Using brain-imaging techniques, the researchers, including Caltech’s Colin Camerer, found that the most lenient jurors show heightened levels of activity in the insula, a brain region associated with discomfort and pain and with imagining the pain that others feel.

The findings provide insight into the role that emotion plays in jurors’ decision-making processes, indicating a close relationship between sympathy and mitigation.

In the study, the researchers, led by Makiko Yamada of National Institute of Radiological Sciences in Japan, considered cases where juries were given the option to lessen the sentences for convicted murderers. In such cases with “mitigating circumstances,” jurors are instructed to consider factors, sometimes including emotional elements, that might cause them to have sympathy for the criminal and, therefore, shorten the sentence. An example would be a case in which a man killed his wife to spare her from a more painful death, say, from a terminal illness.

“Finding out if jurors are weighing sympathy reasonably is difficult to do, objectively,” says Colin Camerer, the Robert Kirby Professor of Behavioral Finance and Economics at Caltech. “Instead of asking the jurors, we asked their brains.” [continue reading…]

 
A new study is tapping into a phenomenon most of us have heard about and some of us might claim to have experienced at some point – “runner’s high”.

In doing so, this study touches on something fundamentally human.

Put simply, our bodies were made to move. Our predecessors were long-distance endurance runners who could work really hard, from an energy-expenditure perspective, if it was required.

Even now, if we really had to, most of us could exert ourselves at a very high level, significantly increasing our energy expenditure, even if was only for a few seconds.

So why don’t we move more? Why are we facing an obesity epidemic driven largely by sedentary behaviour? How come some people enjoy physical activity more than others?

Runner’s high – or the idea of it – is one of the things that drives some people to exercise – a neurobiological reward that occurs during and after distance running, creating a sense of euphoria for the athlete.

This natural high, say some, provides an improved sense of well-being, reduces anxiety, induces post-exercise calm, and can even reduced pain.

But from a “hard-science” perspective, what is this “high” caused by and does it exist beyond the purely psychological? [continue reading…]

The discovery of how the hallucinogen Salvia affects the brain could lead to new avenues for treating drug addiction, chronic pain, and depression.

At the molecular level, drugs like salvinorin A (the active ingredient of the hallucinogenic plant Salvia divinorum) work by activating specific proteins, known as receptors, in the brain and body. [continue reading…]