A sore back or sprained wrist makes your day-to-day life harder in more ways than one. Physical impairment is annoying enough on its own, but the chronic pain is its own distraction – one that makes it hard to focus. It’s been known for a while that chronic pain saps people’s motivation. And now, a team led by Stanford University’s Neil Schwartz has pinned down, in mice, some of the chemical and neural changes by which aches lead to ennui.
Schwartz and his team began by giving two different types of chronic pain to two sample groups of mice – one group got injections that caused soreness in their hind paws, while the other group received some minor surgical nerve damage. Researchers then had both groups compete against pain-free mice in a standard motivational test called a progressive ratio (PR) operant test, in which tasty treats become progressively harder to ...
