Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

This study used the Titchener Circles illusion to investigate the functional dissociation of the dorsal visuomotor and ventral perceptual systems. In order to investigate the visual requirements for an action to be driven by the dorsal stream, two-dimensional (2D) and three-dimensional (3D) targets were compared. Thirteen subjects made visual open loop manual estimations or grasping actions towards 2D and 3D versions of the illusion. No illusion effect was found for immediate grasping, but the illusion did influence manual estimation, irrespective of whether the target was 2D or 3D. It is suggested that the underlying representations used to drive grasping actions towards 2D targets are fundamentally the same as those used to drive natural grasping actions. While stereoscopically specified depth may be important to the dorsal visuomotor system, it does not appear to be necessary in order for an action to be based on dorsal representations. It is suggested that an action must be goal directed in order for that action to be driven by dorsal stream processes.


Journal article



Publication Date





932 - 940


Adolescent, Adult, Dissociative Disorders, Female, Hand Strength, Humans, Illusions, Male, Photic Stimulation, Photography, Psychomotor Performance, Size Perception, Space Perception