The human brain is the most complex organ in the body. Scientists still do not fully understand how it operates; how it can capture images, store them and recall them as vivid memories. Some believe that the brain works like a computer hard drive, in which proteins that bond to neurons communicate and store information. The body's program code may be at an atomic level which would be exponentially greater than the largest and faster computer systems on the planet.
To equate the brain with a computer hard drive is a good comparison. But what happens when a brain misfires? Is it like a crashing hard drive? When information in a computer hard drive is fragmented, the bytes of information are dispersed on various parts of the drive - - - to be sewed back together by the operating code to be then displayed on the screen. In the human brain, when its information and recall gets fragmented, we call it a form of mental illness or disease.
Multiple personality disorders include hallucinations, paranoia, violent behavior, illusions and illogical actions. Those traits were found in many of the main characters in LOST.
One can take the hard drive theory for the show and break it down into differing premises. First, the show could have been a large, on-line multiplayer, role game of Survivor which had its main server programming break down into a different kind of game. Add the component of augmented or virtual reality, the players (characters) could have been so absorbed into the game that it turned into their new reality. Some addictive personalities could then have been trapped in this virtual world.
Second, the premise could be a metaphor that the main characters brains were malfunctioning like a crashed drive. There are many examples of characters shown with mental illness (Hurley and Libby), mental breakdowns and suicidal thoughts (Jack and Locke), murder (Ben, Sawyer, Kate), torture (Sayid and Ben), and even justified homicide (Bernard, Hurley).
There seems to be a great deal of violent criminal behavior as the undercurrent of the series.
The bonds between these main characters could reflect that they were brought to a place collectively in order to protect the rest of the world from them. This idea would fit into the statements by Jacob that he alone brought people to the island. And the fact that MIB was called a "security" system, it would seem they would symbolize a warden and a guard in a prison.
The people brought to the island were not candidates but prisoners. Perhaps it was found that each of the main characters had dangerous mental traits that could trigger abhorrent behavior in the real world. So the authorities ditched them on a private, secluded, high security island to test new penal rehabilitation techniques.
What happened on the island would confirm the authorities worst fears about some of the prisoners. There were violent episodes, Some people changed and went crazy (Claire), others went psychopathic (Ben). Without the structure of prison cells, the inmates ran the asylum.
Which is fine. The prison revolt was orchestrated by the prison guard (MIB) who was fed up with the warden and his games. MIB needed help from the inmates in order to escape the island. But it seems that the only true escape from the island is death.
Third, you can combine the two theories into one in the respect that this prison escape adventure is being a transformative hallucination of a criminal mental patient. The vivid illusions drawn upon the stories of other inmates in therapy sessions can be the building blocks for the action, the escapism, for a person who is serving a life sentence without parole. And the dream aspect could be confirmed by the "happy" ending for the inmates in heaven - - - which is very odd since all their misbehavior, crimes and sins all "vanish" once they leave the island. This is odd finish - - - except that is the fantasy outcome for someone who has committed vile acts without comprehension or accountability or guilt. The dreamers miswired brain allows him or her the fantasy of justification, free will and acceptance by his or her fellow rogues and misfits.