The proposed research tests a theory of visual/spatial representation that addresses the fact that at any moment in time, sensory input delivers only a partial view of the continuous world. In visual scanning, the eyes sample the environment as rapidly as 3-4 times per second, and in haptic exploration (without vision) hands successively examine relatively small regions over time. It is proposed that a single limited """"""""view"""""""" of a scene activates representation of anticipated surrounding space. This anticipatory projection serves to facilitate integration of successive inputs, but also has important implications for memory. Observers remember having seen (or touched) parts of a scene that were anticipated, but never actually experienced (e.g. a phenomenon called """"""""boundary extension"""""""".) In addition to broadening our understanding of spatial representation, the proposed research has implications for individuals with brain damage (e.g., hemi-neglect), and those with sensory deficits. The proposed research will address: a) the effects of planning an eye movement on the ensuing spatial representation of a scene; in particular addressing the issue of whether boundary extension will increase or decrease in the about-to-be-fixated region b) the similarities and differences in spatial representation following visual Vs. haptic (while blindfolded) exploration by sighted observers, and in some cases, those with sensory deficits, c) the accuracy of cross-modal transfer of spatial information, and c) how the relations among objects influence accuracy in memory of spatial layout. Procedures include visual and/or haptic (without vision) exploration of real scenes, or visual exploration of digitized photographs in conjunction with eye tracking techniques. Memory tests will involve recall and recognition procedures as well as new interactive memory tests involving the reconstruction of a view in real space or on a computer screen.
