Brain Studies Highlight Survival Bias and Mescaline's Impact on the Cerebellum

Recent analyses of human cognition describe a built‑in “survival lens” that filters information to prioritize potential threats, leading to a default negativity bias in perception and decision‑making. This interpretive mechanism, rooted in evolutionary pressures, influences how modern individuals evaluate stimuli and social interactions.

A new experimental study using functional MRI on rats examined the effects of mescaline, a psychedelic compound derived from cacti. Researchers found that mescaline reduces activity in parts of the cerebellum while strengthening its connectivity with the hippocampus, thalamus, somatosensory cortex and midbrain, suggesting altered sensory processing and attention under the drug.