Recognition memory, and head injury.

Severely head injured adults were tested on a recognition memory procedure involving the identification of eight recurring shapes among a series of 160. Compared with a control group, the tested patients showed many fewer correct responses. Their type of error was commonly a failure to recognize rather than a false recognition. The severity of the memory deficit was related to the length of post-traumatic amnesia (PTA), but to neither the presence of neurological signs at the time of memory testing, nor to the time after injury at which the patients were tested. The older patients showed a more significant relationship between PTA and memory score than the younger patients.