Memory distortions occur when retrieval of memories are incorrect and information is remembered in a different way than what actually occurred. People reconstruct the past from a variety of sources and mental processes. These processes are far from perfect with individual differences, experiences, and differing perceptions influencing how we reconstruct previous events. Mental distortions are caused by cognitive processes that influence our memory function. Memory distortions have been linked in studies with adaptive mental processes and encoding. Sleep problems, memory retrieval issues, frontal or temporal lobe damage, and PTSD can all result in memory distortions. Research has increased in this area greatly recently due to eyewitness account inaccuracies in court proceedings and false memories being 'recovered' in controversial hypnotic and therapeutic settings.