目的：本研究旨以負重方式探討身體屬性改變對覺知跨越溝渠的環境賦使的影響，身體屬性的改變是否可以直接引起個體的知覺學習。方法：以28 位，年齡18~24 歲的女性為實驗參加者。加附實驗參加者體重30% 重量的鉛塊於腰部改變其身體屬性，實驗過程包含在有、無負重狀態下，判斷最大可跨越距離與最適宜可跨越距離，兩者皆為重覆量數，試作次數的安排均經過平衡消去。實驗的自變項為負重狀態與判斷情況，依變項為知覺跨越距離與實際跨越距離。結果：（一）個體在無負重時，可準確覺知本身的跨越能力，但負重時則低估本身的能力；（二）負重30% 體重重量對知覺跨越能力的影響為降低可跨步距離；（三）呈現方向影響個體的知覺判斷，兩者交互作用達顯著，且漸減的知覺距離比漸增的知覺距離還遠。結論：本研究驗證了Gibson 所主張之環境賦使的概念，在無負重情況中，個體可以準確覺知與環境間的關係。在新關係中（負重），個體則立即覺知與環境間關係的改變，但個體低估可跨越的距離，此低估的情況可能是個體與環境互動機會不足所致。

Purpose: The purpose of this study was to investigate the effects of changed body properties on perceiving affordances for gap-crossing. Methods: Twenty eight female undergraduate students (aged 18~24 years) voluntarily to participate. Participants were required to bear plumbo-block in the waist, which was about 30% of their body weights, and judge their maximal stepping length and optimal stepping length. Results:
Findings were as the following: (1) participants accurately perceived their crossability without bearing weight, but underestimated their crossability when bearing weight; (2)perceived stepping length were reduced when bearing 30% of body weight; (3)direction of presentation affected the judgments; perceived distance was further in the
descending series than in the ascending series. Conclusion: This study investigated perceptual learning of gap-crossing while the properties of individuals changed. People perceived the modification of their body weight immediately; however, they tended to underestimate their crossability when bearing weight. The underestimation might result
from lack of enough interaction with the environment.