Perhaps you saw this movie, staring Jim Carrey. It won the Oscar for writing in 2005, and it was well received by the critics.
The heart of the movie has to do with memory erasure, and the fictional firm Lacuna. The thought is that memories are simply fragments in our mind, and these fragments can be spotted and erased. From the previous section on mind, body, and spirit, you will know that I believe that memories are kept in the physical mind. The question is "will be ever be able to erase memories similar to this movie?"
It may be a surprise to you, but science has just done this.
Protein kinase M zeta is a building block in the brain. It seems that it is especially important in the formation of long term memory. If we give a protein kinase M zeta inhibitor into the cortex of rats brains, and it causes the rats long term memory to go away. It is as if we formatted your hard drive. The data is gone. As a matter of fact, some people think that protein kinase M zeta problems and Alzheimer's disease might be related. The general thought of losing all your long term memory isn't all that interesting, as I forget enough stuff as it is.
What is even more intriguing to me is that we seem to be on the verge of erasing single memories. Work done by Joseph LeDoux, out of NYU, shows a rather interesting implication of using U0126, a protein inhibitor, to kill single memory. The test is rather ingenious.
A rat was taught to fear an electrical shock whenever one of two tones were played. Now, both tones would cause a shock, and the rats would freeze up anytime they heard either tone. The scientist played a tone, and while the rats was in the middle of worrying about a shock, they injected the rat with U0126.
Next day, the previously trained rat didn't remember to worry when the tone was played. However, the truly interesting thing was when the "non-erased" tone was played, the rat froze. In other words, only memory that was erased was the memory going on when the rat was given U0126.
The structure of memories are bound up in synaptic connections inside of the brain. The nature of these synaptic connections are based in proteins. If you disrupt the normal course of these proteins, literally the memory goes away. Think about what you want to forget, and while thinking about this, take U0126.
Boom. Memory gone.
However, it isn't approved for human use. Yet.