Insight, the sudden understanding of a solution or idea, is not only central to creative problem-solving but also plays a key role in psychotherapy, meditation, the emergence of delusions in schizophrenia, and the therapeutic effects of psychedelics. This integrative review draws on literature from multiple fields to examine the event of insight, its prerequisites, and its consequences. It highlights commonalities and differences across these domains, aiming to bridge gaps between disparate research traditions and inspire interdisciplinary efforts to understand this core cognitive process.
A systematic review of 32 placebo-controlled studies from 1990 to 2025 examined the acute and post-acute effects of LSD, DMT, and psilocybin on cognitive and psychological functions. Psychedelics tended to enhance emotional empathy but had no effect on cognitive empathy. Effects on memory varied by task and timing, with some impairments, enhancements, or no change. Dose-dependent impairments occurred in reaction time, attention, and inhibition tasks, though some studies found no effects. Recognition of negative stimuli was impaired under acute effects. Findings on cognitive flexibility were mixed. Many studies had small samples, and finding a reliable placebo is challenging due to psychedelics' unique subjective effects.