Cognitive psychology deals with information processing, and includes a variety of thinking processes including perception, attention, memory, knowledge representation, categorisation, language, problem-solving, reasoning, and judgement. It is also concerned with the structures and representations involved in cognition. Cognitive psychology has significant applications of all areas of human endeavour. It is also the subject of intensive study when applied to health and ageing in the absence of a significant health problem as well as education and human-computer interaction. Other examples are eyewitness memory, autobiographical memory, spatial cognition, skill training, suggestibility , expertise and skilled behaviour.