Pochopien Klaudia, Spang Karoline, Stemmler Torsten, Fahle Manfred
Department of Human-Neurobiology, University of Bremen, Hochschulring 18, D-28359 Bremen, Germany.
Gierather Straße 195 A, D-51469 Bergisch Gladbach, Germany.
Vision (Basel). 2017 Dec 19;1(4):27. doi: 10.3390/vision1040027.
Prisms laterally shifting the perceived visual world cause arm movements to deviate from intended targets. The resulting error-the direct effect-both for pointing and throwing movements, usually corresponds to only around half of the prism's optical power due to an "immediate correction effect". We investigated the mechanisms of this immediate correction effect. In three experiments with 73 healthy subjects we find that the immediate correction effect is associated with a head and/or eye rotation. Since these rotations are subconscious they are not taken into account by the participants. These subconscious rotations compensate for a large portion of the prism's optical effect and change the subjective straight ahead. These movements seem to be induced only in a rich visual environment and hence do not take place in the dark. They correspond to the difference between the direct effect and the optical power of the prisms and seem to cause the immediate correction effect. Hence, eye-hand adaptation only adapts to the prism's optical power minus unconscious head rotation and hence is much smaller than the optical power of the prisms.
使所感知的视觉世界发生横向偏移的棱镜会导致手臂运动偏离预期目标。由此产生的误差——直接效应——对于指向和投掷动作而言，由于“即时校正效应”，通常仅相当于棱镜屈光力的一半左右。我们研究了这种即时校正效应的机制。在针对73名健康受试者开展的三项实验中，我们发现即时校正效应与头部和/或眼睛的转动有关。由于这些转动是下意识的，参与者并未将其考虑在内。这些下意识的转动补偿了棱镜大部分的光学效应，并改变了主观正前方。这些动作似乎仅在丰富的视觉环境中才会被诱发，因此在黑暗中不会发生。它们与直接效应和棱镜屈光力之间的差异相对应，似乎导致了即时校正效应。因此，眼手适应仅适应于棱镜屈光力减去无意识的头部转动，因而比棱镜的屈光力小得多。
