Readers ask about AI ethics, monkey tool use and more

The head and the heart

Scientists used light to raise a mouse’s heart rate, increasing anxiety-like behaviors in the animal. The study offers a new angle for studying anxiety disorders, Bethany Brookshire reported in “In mice, anxiety isn’t all in the head” (SN: 4/8/23, p. 9).

Reader Barry Maletzky asked why strenuous exercise, which elevates heart rate, doesn’t typically induce anxiety.

Heart rate isn’t everything, says neuroscientist Karl Deisseroth of Stanford University. The heart may race, but the brain provides important context, which is key to the body’s response. In the study, elevating a mouse’s heart rate in a neutral environment — such as a small, dim chamber — did not induce anxious behaviors, Deisseroth says.