When we use our hands to estimate the length of a stick in the Müller-Lyer illusion, we are highly susceptible to the illusion. But when we prepare to act on sticks under the same conditions, we are significantly less susceptible. Here, we asked whether people are susceptible to illusion when they use their hands not to act on objects but to describe them in spontaneous co-speech gestures or conventional sign languages of the deaf. Thirty-two English speakers and 13 American Sign Language signers used their hands to act on, estimate the length of, and describe sticks eliciting the Müller-Lyer illusion. For both gesture and sign, the magnitude of illusion in the description task was smaller than the magnitude of illusion in the estimation task and not different from the magnitude of illusion in the action task. The mechanisms responsible for producing gesture in speech and sign thus appear to operate not on percepts involved in estimation but on percepts derived from the way we act on objects.

当我们用手来估计 Müller-Lyer 错觉中一根棍子的长度时，我们很容易受到这种错觉的影响。但是，当我们准备在相同条件下对木棍采取行动时，我们的敏感度要低得多。在这里，我们询问了当人们用手不是对物体进行操作而是用自发的共同语音手势或聋人的传统手语来描述它们时，他们是否容易产生错觉。32 名讲英语的人和 13 名美国手语手语者用手在木棍上动作、估计长度并描述引起 Müller-Lyer 错觉的木棍。对于手势和手势，描述任务中的错觉幅度小于估计任务中的错觉幅度，与动作任务中的错觉幅度没有区别。