Part 1 of the study will assess the enhancement of task-related brain activation (BOLD response) in key brain areas in schizophrenia during the performance of working memory, episodic memory and visual activation tasks as measured by functional magnetic resonance imaging (fMRI) in people with schizophrenia. Part 2 of the study will assess the safety and tolerability of multiple doses of AQW051 in people with schizophrenia.