Amnesia

Amnesia (from Greek Ἀμνησία) is a deficit in memory caused by brain damage, disease, or psychological trauma. Essentially, amnesia is the loss of memory. The memory can be either wholly or partially lost due to the extent of damage that was caused. There are two main types of amnesia, retrograde amnesia and anterograde amnesia. Retrograde amnesia is when previously formed memories are lost. In some cases, the memory loss extends back decades. In other cases the person loses only a few months of memory. Anterograde amnesia is the inability to form new long-term memories. These two types are not mutually exclusive. Both can occur within a patient at one time. Case studies, such as patient R.B., show that both types of amnesia can occur simultaneously. These case studies also show that amnesia is typically associated with damage to the medial temporal lobe. In addition, specific areas of the hippocampus (The CA1 region) are involved with memory. Research has also shown that when areas of the diencephalon are damaged, amnesia can occur.

People suffering with amnesia may still be able to form new memories. Studies have shown that patients can learn new procedural knowledge. In addition, priming (both perceptual and conceptual) can assist amnesiacs in the learning of new non-declarative knowledge.