This is the sister study to the BMS "Cognitive Improvement with Aripiprazole (Abilify)" study (LSUHSC #H04-022). Evaluation of cognitive ability in patients with schizophrenia or schizoaffective disorder both before and after a switch from risperidone, olanzapine, or risperidone Consta injections to aripiprazole may reveal some of the cognitive changes that correlate with the improved response, better side effect profile, and effects on other components of the negative symptom array. Further, examination of brain functional activity using functional magnetic resonance imaging (fMRI) during an episodic memory task, as well as behavioral performance and associated electroencephalographic (EEG) data of working memory and intermediate term verbal memory collected with the Sustained Attention and Memory Brain Function Test (SAM-BFT), may also provide data showing the neural correlates of these changes in cognition.