Limited amnesia occurs in people who suffer a severe physical or psychological trauma, such as a concussion or being rendered unconscious. Football players who suffer concussions and accident victims who are rendered unconscious, typically do not remember what happened immediately before the event. The scientific evidence indicates, however, that some sort of implicit memory may exist which can be troubling to one whose amnesia is due to having been rendered unconscious by an assailant. Schacter notes the case of a rape victim who could not remember the rape, which took place on a brick pathway. The words brick and path kept popping into her mind, but she did not connect them to the rape.
Implicit memory is memory without awareness.
It differs substantially from repressed memory . Implicit memories are not necessarily repressed, nor are they necessarily the result of trauma. They are weakly encoded memories which can affect conscious thought and behavior. Retrieval cues do not bring about a complete memory of some events because most of the event was not encoded. Daniel Schacter and Endel Tulving introduced the terms 'implicit memory' and 'explicit memory' in their attempt to find a common language for those who believe there are several distinct memory systems and those who maintain there is only one such system.