Proceedings of the Annual Meeting of the Cognitive Science Society

Mental spatial transformation processes are often modeled by assuming imaginal processes, highly task-specific assump-tions, or both. We propose the existence of a dedicated, unified cognitive system for the simulation of spatial processes,and show ways to model this system, including an ACT-R implementation that is currently in development. Results ofspatial cognition and brain-imaging research support this proposal. Operations of this system are proposed to be influencedby their complexity, which we assume to be a product of the extent and amount of necessary transformation steps. Thiscomplexity is further assumed to be limited in its extent, possibly explaining decision time effects between task difficul-ties in a mental folding task as being caused by cognitive re-encoding processes. A model for the mental folding tasklacking such a spatial system is presented, serving as a baseline to demonstrate the need of a system dedicated to mentaltransformations.