Redding, G. M. (2008, in preparation). Virtual and Drawing Structures for the Müller-Lyer Illusions.

Goodness of fit was assessed for the Müller-Lyer illusions to predictions from 3-D virtual structures used to generate stimulus drawings. Virtual structures were right angle convex and concave corners in front of and behind the picture plane, respectively. Virtual corner size was manipulated directly (Experiment 1) and indirectly by manipulating drawing station point distance (Experiments 2 & 3) and corner distance from the picture plane (Experiments 4 & 5). Experiments 2 and 4 held the size of the projected corner edge or interior target line constant causing virtual corner size to vary, while Experiments 3 and 5 held size of the virtual corners constant causing size of the projected corner edge or interior target line to vary. Subjects reproduced the length of the projected corner edge (interior target line). The illusions (difference between reproduced size of the projected corner edge and T-junction control) were generally well fit by the weighted sum of virtual corner size and size of the projected corner edge, but the projected distance between boundary line terminations (inter-tip distance) appeared as an additional contributing factor in Experiment 4. The implications of this methodological approach are discussed for scene-based, picture-based, and object-based theories of illusions

Redding, G. M., & Wallace, B. (2008, November, submitted). Visual Prism Adaptation in Left-Handed Subjects. Prepared for presentation at the 49th annual meeting of the Psychonomic Society, Chicago, IL.

The left hand of left-handed subjects was exposed to leftward or rightward prismatic displacement under exposure conditions that produced visual realignment. Results are compared with similar data from right-handed subjects. For left-handers change in visual straight ahead transferred to the exposed left hand, but not to the unexposed right hand. In contrast, for right-handers change in visual straight ahead transfers to the exposed right hand, but not to the unexposed left hand. These results suggest that limb control is lateralized for right-handers, but not for left-handers.

Redding, G. M., & Wallace, B. (2008, submitted). Implications of Prism Adaptation Asymmetry for Unilateral Neglect: Theoretical Note. Cortex.

Asymmetry in intermanual transfer of proprioceptive and visual prism adaptation is reviewed, which suggests asymmetric hemispheric representation of left and right space, directional connection from right to left visual hemispheres, and lateralization of limb motor control. Damage to the right visual hemisphere source of the directional connection could produce the general features of unilateral neglect