Differences between right versus left lateral body tilt in its effect on the visual and tactual perception of verticality

Summary Ninety six Ss were subjected to lateral body tilt, ranging from 10° to 90° to the right and to the left, and indicated the visual vertical (by means of a luminescent rod) and the tactual vertical (by means of a metal bar) in a darkroom. There were significant differences for deviations of apparent from true vertical in both series between body tilt to the right versus to the left. With tilts to the right, apparent vertical deviated more opposite the direction of tilt, the E-phenomenon, or less in the direction of tilt, the A-phenomenon, as compared with tilts to the left.This study was supported, in part, by a Public Health Service Research Grant, MH 00348, from the National Institute of Mental Health, while the author was a NATO research fellow at Clark University, Worcester, MA; and in part by a Federal Grant, MR HD 06276, to the Children's Hospital Medical Center, while the author was a research fellow in child psychiatry at Harvard University, School of Medicine, Boston, MA.