Wann J P, Ibrahim S F
Department of Psychology, University of Edinburgh, UK.
Exp Brain Res. 1992;91(1):162-6. doi: 10.1007/BF00230024.
The hypothesis that proprioceptively perceived limb position drifts during visual occlusion was re-examined by combining some of the protocols used in previous experiments. Sixteen adult subjects made judgements of static limb position during visual occlusion lasting up to 2 min. In addition, the effect of brief 250 ms "glimpses" of the limb, occasional proprioceptive stimulation and directed attention were examined. Despite, conflicting evidence from earlier experiments, there was clear evidence of a drift in perceived limb position, towards the body, during visual occlusion. This drift was halted if brief glimpses of the limb were provided, or minor re-positioning (without vision) was allowed. In neither case, however, did the supplementary cues reset limb position to its originally perceived position. Drift was amplified when subjects attempted to attend to limb position rather than perform a secondary tracking task. The results are not easily accounted for if drift is considered purely as an effect of peripheral sensor adaptation. A notion of central-drift between visual and proprioceptive maps is suggested as an alternative hypothesis.
通过结合先前实验中使用的一些方案，对视觉遮挡期间本体感觉所感知的肢体位置会漂移这一假设进行了重新检验。16名成年受试者在持续长达2分钟的视觉遮挡期间对静态肢体位置进行判断。此外，还研究了肢体短暂250毫秒“瞥见”、偶尔的本体感觉刺激和定向注意力的影响。尽管早期实验有相互矛盾的证据，但有明确证据表明在视觉遮挡期间，所感知的肢体位置朝着身体方向漂移。如果提供肢体的短暂瞥见，或者允许进行轻微的重新定位（无视觉），这种漂移就会停止。然而，在这两种情况下，补充线索都没有将肢体位置重置到其最初感知的位置。当受试者试图关注肢体位置而不是执行次要跟踪任务时，漂移会加剧。如果将漂移纯粹视为外周传感器适应的结果，那么这些结果就不容易解释。有人提出视觉和本体感觉图谱之间的中枢漂移概念作为一种替代假设。
