If the information isn't further processed, it will soon be forgotten. Short term - new information is stored for a brief time.It seems that the brain has a number of different memory forms, including: Memory storage in clusters of nerve cells (neurones).Localised memory areas in certain structures of the brain only.Widespread distribution of memories, with certain structures (such as the hippocampus) playing important roles.Widespread distribution of memories across the outermost layer of the brain (cortex).Current and often conflicting theories include: The way the brain codes and stores information remains a mystery. Transient ischaemic attack (a 'mini stroke').Certain drugs, such as barbiturates or heroin.Memory loss can be caused by a wide range of conditions, including: Once the person recovers, they typically have no memory of their amnesia episode.Inability to recognise familiar faces or places.The symptoms of amnesia depend on the cause, but generally include: It is thought that the memory processes of the brain take time to develop. Infantile amnesia, or the inability to remember anything at all from the first few months or years of life, is universal. In many mild cases, such as those caused by concussion, the person can't recall the blow to the head or their recovery time, but the rest of their memory is intact.

Anterograde amnesia means that the person can't learn anything new, while retrograde amnesia means the person forgets events from their past. Causes include head and brain injuries, certain drugs, alcohol, traumatic events, or conditions such as Alzheimer's disease. The loss can be temporary or permanent, but 'amnesia' usually refers to the temporary variety. Amnesia is a general term that describes memory loss.

Anterograde vs retrograde amnesia