Verbal memory (memory for words) is divided into three stages: 1) encoding, in which information in first taken in, and related to the left prefrontal cortex; 2) consolidation, in which memories are stored for later use, and related to the hippocampus; and 3) retrieval, in which we extract the stored information, usually related to the right prefrontal cortex.
Although direct injuries to the prefrontal cortex can disrupt the memory process, diffuse axonal injury (where the connections from one brain area to another are damaged) can also disrupt memory. Unfortunately, when one stage of the memory process is disrupted, the whole process is also disrupted, and it can be difficult to know the exact origin of the problem.
Recent research has suggested that traumatic brain injury patients have problems specifically with encoding and consolidation stages of memory. In addition, problems with consolidating information can improve over time, but encoding new information remains problematic even after recovery. Therefore, rehabilitation programs that focus on the encoding of new information can be specifically useful for traumatic brain injury patients.
Wright MJ, & Schmitter-Edgecombe M. The impact of verbal memory encoding and consolidation deficits during recovery from moderate-to-severe traumatic brain injury. Journal of Head Trauma Rehabilitation. (June 2011).