Visual illusions have provided compelling evidence for a dissociation between perception and action. For example, when two different-sized objects are placed on opposite ends of the Ponzo illusion, people erroneously perceive the physically smaller object to be bigger than the physically larger one, but when they pick up the objects, their grip aperture reflects the real difference in size between the objects. This and similar findings have been demonstrated almost entirely for the right hand in right handers. The scarce research that has examined right and left-handed subjects in this context, has typically used only small samples. Here, we extended this research with a larger sample size (more than 50 in each group) in a version of the Ponzo illusion that allowed us to disentangle the effects of real and illusory size on action and perception in much more powerful way. We also collected a wide range of kinematic measures to assess possible differences in visuomotor control in left and right handers. The results showed that the dissociation between perception and action persisted for both hands in right handers, but only for the right hand in left handers. The left hand of left handers was sensitive to the illusion. Left handers also showed more variable and slower movements, as well as larger safety margins in both hands. These findings suggest that grasping in left handers may require more cognitive supervision, which could lead to greater sensitivity to visual context , particularly with their dominant left hand.

视觉错觉为感知与行动之间的分离提供了令人信服的证据。例如，当两个不同大小的物体被放置在庞佐错觉的两端时，人们会错误地认为物理上较小的物体比物理上较大的物体更大，但当他们拿起物体时，他们的握力孔径反映了真正的差异物体之间的大小。这一发现和类似的发现几乎完全针对右撇子的右手得到了证实。在这种情况下，对右手和左手受试者进行研究的稀缺研究通常只使用小样本。在这里，我们以更大的样本量（每组超过 50 个）在庞佐错觉版本中扩展了这项研究，这使我们能够以更强大的方式理清真实和虚幻大小对行动和感知的影响。我们还收集了广泛的运动学测量值，以评估左利手和右手利手视觉运动控制可能存在的差异。结果表明，右利手的双手仍然存在感知和行动之间的分离，但左利手的右手只存在感知和行动之间的分离。左撇子的左手对幻觉很敏感。左撇子的动作也更加多变和缓慢，双手的安全裕度也更大。这些发现表明，左利手的抓握可能需要更多的认知监督，这可能会导致对视觉环境的敏感性更高，尤其是他们的惯用左手。