In the Northeast, the leaves have started changing colors, heralding the season of pumpkins, sweaters, and the smell of woodsmoke. But in some parts of the country, the heat hasn’t let up. In cities like Dallas, Phoenix, and Miami, temperatures were up in the high 80s and low 90s this week—and with climate change, the U.S. is only getting hotter. 

But humans have come up with an ingenious way to keep the heat at bay: air conditioning. Widely considered one of the greatest engineering achievements of the 20th century, the technology has transformed how and where people live—and it’s prevented countless deaths. But it comes at a cost, and if we’re going to keep up with a warming climate, we’re going to need some other tricks to stay cool. 

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What happens when you see a familiar face? Light reflected from the face enters your eye, is focused onto the retina, and a signal travels up your optic nerve. But what exactly goes on in your brain after that is still somewhat mysterious.  

Recently, researchers reported in the journal Science that they had identified a group of brain cells that seem tuned to respond only to familiar faces. The theory is that the specificity of those neurons helps to speed up processing of potentially important visual information. The work was done in monkeys, but the researchers are currently trying to identify similar brain structures in people.  

Sofia Landi and Winrich Freiwald, two of the authors of the report, join Ira to talk about the research, and what it may tell us about how the brain and memory are organized.