Psilocybin, a serotonin 2A receptor agonist, facilitates extinction of conditioned fear responses in mice, with low doses producing faster extinction than high doses or saline. The drug also reduces hippocampal neurogenesis in a dose-dependent manner, but the low doses that enhanced extinction did not decrease neurogenesis and instead showed a trend toward increase. This suggests that psilocybin's effect on fear extinction may involve brain regions other than the hippocampus, such as the amygdala, which processes fear perception. Psilocybin and similar agents warrant exploration as potential treatments for post-traumatic stress disorder and related conditions.
Boredom arises when people cannot engage with their surroundings even though they want to. It feels negative and is linked to depression and aggression. Using brain scans, researchers found that during boring tasks and boredom-inducing videos, a brain region called the anterior insula cortex showed activity that moved in the opposite direction from the default mode network (DMN), a set of regions active when the mind wanders. In contrast, when participants felt interested, the anterior insula worked in sync with both the DMN and attentional control regions. This suggests boredom reflects a failure to engage brain networks needed for focusing attention during monotonous activities.