How do you erase certain parts of the memory?

[Sexbad]

Yeah. I actually just look at things when I'm bored but never become entranced in them, even when it's swinging.

I mean I just stare at stuff for minutes on end and nothing happens.

[MulleDK19]

I, personally, find it hard to believe that you can just...snap your fingers and make someone forget something. The human brain is just too complex for that kind of thing. We are not like computers where you can just go to the Recycle Bin and hit "empty". I honestly don't care if hypnosis is real or not...but the manipulation of one's memories through repetitive hand waving and saying "You will forget having played the game Penumbra!" is just impossible...unless someone can tell me exactly how it works.

EDIT: I'm not trying to be a pain in the neck or piss anyone off. I just want someone to definitively explain to me how it works.

The subconscious is the part of your mind that controls your feelings, thoughts and actions.

Hypnosis is a relaxation state, pretty much like REM-sleep, and a hypnotist is able to bypass the critical factor, by which he can gain access to your subconscious.

While under hypnosis you become susceptible to suggestions, and the subconscious is very powerful.

The subconscious is in fact so powerful, that you could be told that your hand is burning, and you would instantly feel an insane pain.

It's also a fact that we all undergo hypnosis averagely 7 times a day, and we all experience hypnotic phenomena all the time.

Like amnesia. For example, if you hum or hear a song, or seen a person but do not remember his name. You know you're supposed to remember, and it's as if it's at the tip of your tongue, but you can not get it out.

A hypnotist is able to create these phenomenas through hypnosis.

[eliasfrost]

This might be possible, but I highly doubt that it's going to be efficient in any way. You simply can't remove all traces of a memory. For this to work, I assume the patient need to be under a hypnosic state during the process? I mean, he needs to be hypnotized _while_ playing the game?

Although I have no doubts that you can lure and/or remove parts of your memory, there are certain parts that simply can't be removed, things controlled by instinct, like walking. I've heard about people with amnesia, they usually forget the name of people but not(for instance) what a fork is and how to use it. Is there some kind of mystery behind this?

[Kedjane]

This might be possible, but I highly doubt that it's going to be efficient in any way. You simply can't remove all traces of a memory. For this to work, I assume the patient need to be under a hypnosic state during the process? I mean, he needs to be hypnotized _while_ playing the game?

Although I have no doubts that you can lure and/or remove parts of your memory, there are certain parts that simply can't be removed, things controlled by instinct, like walking. I've heard about people with amnesia, they usually forget the name of people but not(for instance) what a fork is and how to use it. Is there some kind of mystery behind this?

Actually I've read a bit about memories and such and it's a bit obvious you haven't, at least not a lot.
I'm not expert or anything but memories aren't just that, there are "long time memories" and "short time memories". Long time memory is things like what your name is, where you live and how to write and short time memories are things like what was the last key you pressed or the last meal you had.
Only if something is considered "important to remember" by the brains automatic process (which you can't fully controll, which is why you can't remember some things even if you try really hard) it is moved from the short time memory to long time memory.

I think memories are "processed" and sorted into the brains "remember"/"forget" folders about six hours after something happening. This I read is why you for example after a traumatical can forget it if you play Tetris for roughly one hour about six hours after the event.
I don't know when non-traumatical events are processed, but there might be a rough estimate of that time too and could theoretically be used for removing good memories aswell, though a short time after playing the game.

This is more of an answer to that last part about amensia actually, but I think people with amnesia forget both their short time and long time memories, but they still have the bodys instict memories such as how to eat (and do fancy ninja moves, if you're Jason Bourne) but you can't remember things not a part of all people such as individual names and such.

Anyhow: if you can prevent memories from storing in the first place I don't doubt you can by lots of hypnotisation be made to forget something. Afterall if someone showed me a picture of the very first room in the Penumbra Tech Demo, but with red boxes instead of green, not having played the Tech Demo in a while just that might be enough to alter my memory and make me remember them as green.

But I've got to go so I can't elaborate any more right now.