PMID: 5243948 Issn Print: 1040-5488 Publication Date: 1968/07/01 Print Facebook Twitter LinkedIn Email EFFECTS OF EXCITATORY AND TRANQUILIZING DRUGS ON VISUAL PERCEPTION* Richard M. Hill; Roland Fischer; Diana Warshay Checking for direct PDF access through Ovid View on Journal Site Abstract Changes of spatial distortion threshold in response to the hallucinogen, psilocybin, were measured. A marked loss of compensation for optically induced distortions at drug peak was found. Compensation returned as the drug course elapsed. View on Journal Site