but i need the "why"

Placing humans who have damaged brains in virtual environments is one way of enhancing their levels of environmental interaction which, because of cognitive impairments and sensory and motor disabilities, is otherwise difficult to achieve....someone sustaining damage to the brain is likely to face a sudden and dramatic change in his or her normal pattern of environmental interaction. First, loss or reduction of sensory or motor capacity will limit opportunities for interaction. Secondly, even those interactions which remain within the person's sensory and motor capacities may be distorted because of cognitive impairments. Finally, reduced activation-arousal will necessarily impose a further limitation on capacity for meaningful interaction. In terms of environmental enrichment and impoverishment brain damage must be seen as potentially causing considerable impoverishment.

(VIRTUAL ENVIRONMENTS IN BRAIN DAMAGE REHABILITATION: A RATIONALE FROM BASIC NEUROSCIENCE F. D. ROSE, E. A. ATTREE, B. M. BROOKS, D. A.JOHNSON Department of Psychology University of East London, London, UK)

this is gettin repetitive...enrichment is good, yes i got it, we all got it.. sometimes enrichments causes stress and stimulates sometimes stress is not good as it causes anxiety.. anyway architecture doesn't have to stimulate in one way.. that s my conclusion