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. The anxious behaviors increased only when the heart rate was raised in a threatening context, like an open space where a small mouse could be a snack for a predator.
Monkey business
Some macaques inadvertently made stone flakes while using rocks to crack open nuts, raising questions about whether ancient stone flake tools attributed to hominids were made accidentally, Bruce Bower reported in “Monkeys’ stone flakes look like hominid tools” (SN: 4/8/23, p. 13).
Reader Jerald Corman wondered how scientists knew that the monkeys created the stone flakes unintentionally.
We know this because the flakes were produced only when a monkey attempted to hit a nut with a rock and missed, says primatologist Lydia Luncz of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. The monkeys “pay absolutely no attention to whatever breaks off. They don’t pick it up. They don’t look at it,” she says. “When a stone breaks multiple times, they just pick a new one.”
AI ethics
The chatbot ChatGPT and other artificial intelligence tools are disrupting education, Kathryn Hulick reported in “Homework help?” (SN: 4/8/23, p. 24).
The material that ChatGPT generates is…
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