Ketamine disrupts consciousness in healthy participants in relation with psychotic-like symptoms.
bioRxiv : the preprint server for biology November 8, 2025 Lucie Berkovitch, Alexandre Salvador, Thomas Andrillon et al. preprint
Low doses of ketamine, an NMDA-receptor antagonist, disrupt the ability to consciously perceive visual information in healthy people. In a double-blind, placebo-controlled experiment with 21 volunteers, ketamine increased visual masking and reduced conscious perception of a digit. The N1 component of brain activity, an early marker of visual processing, was significantly reduced under ketamine and correlated with conscious access. Ketamine also induced psychotic-like and manic-like symptoms, but only the psychotic-like dimension was linked to impairments in conscious access. These findings suggest ketamine attenuates early visual brain responses, impairing conscious access, and that this mechanism differs in some ways from that seen in schizophrenia.