Amnesia is a condition characterized by the inability to form new memories or the inability to recall existing memories. Amnesia is caused when the
hippocampus or thalamus becomes damaged. This can be the result of a
blow to the head, a stroke, surgery, alcoholism or certain types of infections.
One of the most common misconceptions about amnesia is that people forget everything that they ever knew. In reality, it's
episodic memory which is most impaired. Intelligence, attention and creativity are generally unaffected.
Anterograde amnesia refers to a condition where the sufferer cannot make new memories. They can still recall memories from before the condition started, but not from any experiences that occur after the onset of amnesia. This is because the brain becomes unable to convert
short-term memories into
long-term memories.
Retrograde amnesia is when the person is capable of forming new memories, but is unable to remember anything that happened before the onset of amnesia. Amnesia patients may experience both types of amnesia to different degrees.
Another misconception, fueled by cartoons and Hollywood movies, is that a second impact to the head can completely reverse the condition. In reality, a second impact would cause increased memory impairment. There are no specific treatments for amnesia, but conditions generally improve over time as the injury that caused it heals.