Psychedelic compounds like LSD, psilocybin, mescaline, and DMT can dramatically alter visual perception, but whether these visual effects consistently differ between substances is unclear. Using the large Erowid experience report dataset, researchers analyzed narrative self-reports for 103 psychoactive substances, including 30 psychedelics and 73 comparison substances. They used an AI embedding model to classify sentences describing visual effects. The proportion of visual-effect sentences varied significantly and consistently across substances, even among psychedelics. Further analysis of visual effect categories—such as movement, color, and pattern—also showed reliable variation. The findings indicate that different psychedelic substances have distinct propensities to affect vision and produce qualitatively different visual experiences.
Facing pairs of human heads gain privileged access to conscious awareness compared to nonfacing pairs, even when presented outside awareness. Eleven experiments using a breaking continuous flash suppression paradigm showed that two human faces facing each other broke into awareness faster than nonfacing pairs. This advantage could not be explained by low-level or mid-level visual features. Disrupting holistic processing of the two agents significantly reduced the facing advantage. The effect was specific to human agents and did not occur with daily objects, directional arrows, or nonhuman animals. These results suggest that social information, specifically the facingness between two individuals, can be integrated unconsciously and influences what reaches conscious awareness.