Impaired Velocity Processing Reveals an Agnosia for Motion in Depth

TY - JOUR

T1 - Impaired Velocity Processing Reveals an Agnosia for Motion in Depth

AU - Barendregt, Martijn

AU - Dumoulin, Serge O

AU - Rokers, Bas

N1 - © The Author(s) 2016.

PY - 2016/11

Y1 - 2016/11

N2 - Many individuals with normal visual acuity are unable to discriminate the direction of 3-D motion in a portion of their visual field, a deficit previously referred to as a stereomotion scotoma. The origin of this visual deficit has remained unclear. We hypothesized that the impairment is due to a failure in the processing of one of the two binocular cues to motion in depth: changes in binocular disparity over time or interocular velocity differences. We isolated the contributions of these two cues and found that sensitivity to interocular velocity differences, but not changes in binocular disparity, varied systematically with observers' ability to judge motion direction. We therefore conclude that the inability to interpret motion in depth is due to a failure in the neural mechanisms that combine velocity signals from the two eyes. Given these results, we argue that the deficit should be considered a prevalent but previously unrecognized agnosia specific to the perception of visual motion.

AB - Many individuals with normal visual acuity are unable to discriminate the direction of 3-D motion in a portion of their visual field, a deficit previously referred to as a stereomotion scotoma. The origin of this visual deficit has remained unclear. We hypothesized that the impairment is due to a failure in the processing of one of the two binocular cues to motion in depth: changes in binocular disparity over time or interocular velocity differences. We isolated the contributions of these two cues and found that sensitivity to interocular velocity differences, but not changes in binocular disparity, varied systematically with observers' ability to judge motion direction. We therefore conclude that the inability to interpret motion in depth is due to a failure in the neural mechanisms that combine velocity signals from the two eyes. Given these results, we argue that the deficit should be considered a prevalent but previously unrecognized agnosia specific to the perception of visual motion.

U2 - 10.1177/0956797616663488

DO - 10.1177/0956797616663488

M3 - Article

C2 - 27677897

SN - 0956-7976

VL - 27

SP - 1474

EP - 1485

JO - Psychological Science

JF - Psychological Science

IS - 11

ER -