50 years ago, scientists thought that animals brains were prediction making machines. But a new model suggests they are actually computing the difference between what they predicted and what actually happened. Dopamine's job is to say when a reward or an event is meaningful enough for you to look around for a possible cause.
The response to the death of the 29-year-old has differed from that of previous cases of police killings; we ask what the tragedy indicates about how America deals with police violence. Our correspondent says a lawmaker’s murder in Afghanistan highlights the misery of women under the Taliban. And why a decades-old model of animal and human learning is under fire.
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