Inception is quite a dazzling ride, a heist movie that will be loved by all who loved films like The Sting and Oceans 7.

But are any of the dream actions in the film really possible? This question was posed to the International Association for the Study of Dreams, who members research dreams and dreaming for a living. asdreams.org I will summarize the research below.

Possbible to be aware you are dreaming? Yes, typically this is called Lucid Dreaming, and lucid dreaming has been scientifically studied for decades. In lucid dreaming, a person is aware they are dreaming, while dreaming, and they continue dreaming.

Possible that OTHER people are in the same dream you are in? Yes, but the evidence is slim and the changes of guiding this even slimmer. Typically these are called Mutual Dreams.

Possible to be both Lucid AND in a Mutual Dream? Again, yes, but the chances and evidence is very slim. I think it is best to watch the film Inception with the view that the dream machine and drugs used in the movie are super-charging, guiding and restricting this ability.

Possible to influence another person's dreams? Yes, we do this all the time, though again, the chances are slim that one can influence a dream to the degree seen in the Inception. Typically objects and actions and scenes (or architecture) are incorporated in more singular ways, or ways that are integrated into the dreamer's own dream theme, like flashing a light on the dreamers eyes, and the dreamer seeing a flying saucer flashing in his or her dream.

Possible to have one person's dreamscape, but another person's unconscious populate that dream? Again, with mutual dreaming that is possible, but highly unlikely.

Possible to have a dream within a dream? Yes, this is a common practice among many indigenous peoples and their shamans.

Possible to have a false awakening? Yes, people have false awakenings all the time, where they think they are awake, but actually still dreaming.

Possible for time to go faster in a dream, that a dream seems a lot longer than the actual time dreamed. Well, yes and no. Research shows that people can generally judge the time they were dreaming if awakened. But many people have had dreams where they at least felt that hours, days, even years went by. So again, I would say that it is best to look at the time differentials in Inception as an effect of the dream drugs and machine.

Possible for Dream Projections to attack people that try to change the dream? Yes, sometimes. It was the original theory of Freud that dreams protect sleep, and this is not a far cry from that that view. It is unlikely to happen in the way the film depicts.

Possible for a dead person to appear in a dream and haunt a person? Yes, happens all the time.

Possible to have a totem that tests reality? No. A spinning top can just as easily stop in a dream as keep going. The way most lucid dreamers test whether it is a dream or not is by hovering. If you can hover, you are probably dreaming.

Are there drugs that induce dreaming? Yes, there are many substances and drugs that enhance dreaming, and some tend to enhance lucid dreaming.

Are there dream machines? Not as advanced as the ones portrayed in Inception, but yes, there are many machines used for lucid dreaming.

Bottom line, these dream scenes are possible but highly unlikely. I recommend thinking of them as effects of the dream machine.

Richard Wilkerson, Operations Director, IASD