Human Updating of Visual Motion Direction During Head Rotations

Abstract

Ruiz-Ruiz M, Martinez-Trujillo JC. Human updating of visual motion direction during head rotations. J Neurophysiol 99: 2558 -2576, 2008. First published March 12, 2008 doi:10.1152/jn.00931.2007. Previous studies have demonstrated that human subjects update the location of visual targets for saccades after head and body movements and in the absence of visual feedback. This phenomenon is known as spatial updating. Here we investigated whether a similar mechanism exists for the perception of motion direction. We recorded eye positions in three dimensions and behavioral responses in seven subjects during a motion task in two different conditions: when the subject's head remained stationary and when subjects rotated their heads around an anteroposterior axis (head tilt). We demonstrated that after head-tilt subjects updated the direction of saccades made in the perceived stimulus direction (direction of motion updating), the amount of updating varied across subjects and stimulus directions, the amount of motion direction updating was highly correlated with the amount of spatial updating during a memory-guided saccade task, subjects updated the stimulus direction during a two-alternative forced-choice direction discrimination task in the absence of saccadic eye movements (perceptual updating), perceptual updating was more accurate than motion direction updating involving saccades, and subjects updated motion direction similarly during active and passive head rotation. These results demonstrate the existence of an updating mechanism for the perception of motion direction in the human brain that operates during active and passive head rotations and that resembles the one of spatial updating. Such a mechanism operates during different tasks involving different motor and perceptual skills (saccade and motion direction discrimination) with different degrees of accuracy.

Similar perceptual costs for dividing attention between retina- and space-centered targets in humans

“…Viewing was binocular. In order to avoid subjects using the screen's square edges or any other environmental cue as a reference for perceiving the orientation of the target, they viewed only a portion of the screen through a black cylinder (aperture 45 cm), rendering the visible area circular (Figure 1, see also Ruiz-Ruiz & Martinez-Trujillo, 2008). Responses were collected via a standard keyboard.…”

“…The eye tracker was fixed to the head and firmly adjusted in order to avoid translational movements of the transducers relative to the subjects' head (DiScenna, Das, Zivotofsky, Seidman, & Leigh, 1995). We have previously used this procedure in a more demanding task in terms of head stabilization and it proved to be accurate (Ruiz-Ruiz & Martinez-Trujillo, 2008).…”

Neuronal and Perceptual Effects of Selective Attention in the Primate Visual System

“…Viewing was binocular. In order to avoid subjects using the screen's square edges or any other environmental cue as a reference for perceiving the orientation of the target, they viewed only a portion of the screen through a black cylinder (aperture 45 cm), rendering the visible area circular (Figure 1, see also Ruiz-Ruiz & Martinez-Trujillo, 2008).…”

“…The eye tracker was fixed to the head and firmly adjusted in order to avoid translational movements of the transducers relative to the subjects' head (DiScenna et al, 1994). We have previously used this procedure in a more demanding task in terms of head stabilization and it proved to be accurate (Ruiz-Ruiz and Martinez-Trujillo, 2008). The horizontal and vertical eye position components were monitored on-line at a sampling frequency of 100 Hz.…”