The study of how memory works and does not work has been very extensive within psychology, particularly within the areas of cognitive psychology and neuropsychology. The major kinds of conditions that produce amnesia include various types of brain damage or accidents, such as head trauma, strokes, brain infections (e.g encephalitis), and degenerative diseases (e.g. Alzheimer's disease). Temporary amnesia has also been evidenced following electroconvulsive therapy for psychiatric conditions. There are different types of amnesia including anterograde, retrograde or psychogenic amnesias. Five brain regions have been consistently associated with memory loss: anterior temporal cortex, medial temporal area, medial thalamus, mamillary bodies and basal forebrain.