Cognition is a complex set of processes, including, attention, learning and memory, and can be defined as the capacity to attend, encode, consolidate, store and retrieve recent and remotely stored fact (semantic) and experience based (episodic) memory. Different brain regions, circuits, and substrates subserve different types of memory. While long-term memory for experiences and fact-based information are generally supported within the medial temporal lobe, short-term memory involves primarily the prefrontal cortex and certain areas of the posterior cortex and the hippocampus. Cognitive impairment is a defining feature of several neurodegenerative and psychiatric disease (e.g. Schizophrenia, Alzheimer's Disease and Huntington Disease).