Memory and information processing capacity after closed head injury.

The relation between duration of post-traumatic amnesia (PTA), performance on memory tests, and the Paced Auditory Serial Addition Task (PASAT) was examined in two samples of young adult closed head injury patients. Three different effects were isolated: (1) an attention and concentration factor, related to PASAT scores, (2) a deficit in the ability to place material into long-term memory storage, related to PTA durations, and (3) an impairment in the ability to retrieve material once it has been stored, which was not predicted by either PTA or PASAT.