That kinda depends on
which kind
of cell. There are primitive, open-ended, unactivated cells (ala stem cells); and then there are individuated, activated, specialized cells (like brain cells).
An adult human being is made up of a whole lot of different kinds of specialized cells. Some of these specialized cells make up one's brain, which thinks and feels and remembers and reasons.
But early on in the human life cycle, everyone starts out as a single-cell organism, in the form of a fertilized egg or zygote. This cell is open-ended, in that various parts of its DNA can become activated to cause the cell to become anything within a human body.
But it does not actually do so. Instead, the zygote divides and multiples, producing near-exact copies of itself. And this continues, with the cells multiplying so many times that they form a tiny little soccer-ball-looking mass. At this point, the cells are all still copies of one another, with no specialization and no individuation.
Eventually, the ball of cells grows sufficiently that a hollow pocket forms inside the ball. It is at this point that the cells begin to demonstrate some differentiation from one another. The cells on the inside of the hollow ball begin to perform certain functions that differ from the cells on the outside of the ball. This lining of differentiated interior cell goes on to become the inner organs of the gestating human being, and the outer lining of cells goes on to become the muscles, skeleton, and skin.
The question as to when a self/psyche/mind or soul develops within a human being has not been definitively answered. Some religions claim that an external spirit is attached at the moment of conception in the womb. But there is no evidence of mind within a zygote, or even at the blastocyst (hollow ball of cells) stage of the human life cycle.
I suppose that one could study psychology and try to pinpoint an exact moment when a self/psyche/mind presents itself.
But it seems to me that a mind doesn't just pop into existence, all at once. It is a gradually unfolding, developing thing. Just as the cells within an in-utero human being take on new, specific roles and functions that differentiate them from one another; a young human being slowly and gradually begins to respond to its surroundings in a way that demonstrates that it is becoming aware of those surroundings, and ultimately aware of itself too.
To my knowledge, no one human cell is capable of this. Human thought and emotion require an interplay of numerous different types of specialized cells. Self-awareness happens when there are a sufficient number of specialized brain cells to make it happen, and there are a sufficient number of other types of body tissue cells to support it, and there are a sufficient number of external experiences for the young human being to learn to differentiate itself from its surroundings.
It's not so much "when did a human being become self-aware?" (single precise moment in time), so much as "when was a human being becoming self-aware?" (a more extended time interval).

Uh oh, Sunray. You misspelled some words in yer post. Better be prepared for batterson the Word-Cop to come swooping down and chastise you properly and then throw you in Word-Jail for yer highly improper and criminal misuse of yer computer's keyboard!!1!1one
"A turtle without moisture is like a paperweight with nostrils."

All these answers were quite correct-especially the one with stated Hawkings,Richard therebut this is all so depict of what one call deconstruction of tought and feelings,just what it is like speaking and writingthat is to say that the logocentric point of wiev dont hold up in the primordian man-because there was not the word,the logon in the beginningin the beginning was thisthen the logic came out and people were satisfyed becaquse life had a meaning..in reality we create our own meaning,trough children,arts,women etcita all uo to youbut there are good choices and bad ones.

This post is absurd. What is the difference between a cell and a human? If you are trying to equate them, they can only ever be on equal grounds in the most abstract sense - that is, in the idea that they both are 'alive'. But you should realize, in order to arrive at such an abstract answer, you had to strip away or ignore a lot of inconvenient data - like, everything that separates and distinguishes a man from a cell, which is millions and millions of points!
Not to mention, the idea that a cell and a human are alive in the same way is a inherent literary bias that stems from the literate world's fascination with uniform continuity. If a cell is alive, it is not alive in the same way in which our word alive signifies, it is merely that there is no truly appropriate word for the unique 'aliveness' of a cell, particularly because we have no experience with such a state.
Here is one major different: a man is composed of cells, a cell is not composed of men. How can you try to align these two things?

The word is consciousness (not "conciuosness"). And brain (not "brran").

Might be slightly off topic but has it not been confirmed that Dolphins are self aware? And therefore have a state of self consciousness similar to humans?
~What if this is as good as it gets?!~

Aomeba, a single cell organism is self aware and has conciuosness, while being a single cell. It is unknown if it is aware of its conciuosness, jsut like its unknown if, say, bears are. We often call the electronic inpulses in our brran that is what creates the though "soul". it is however in no way similar to what religion wants us to think.
Applied Science? All science is applied. Eventually.

You mean its parts (not "it's"). It's = it is

Killing people is easyif you can forget the taste of sugar.

The whole is more than the sum of it's parts.

This message has been deleted.

It is. But the character in question seems like the kind of intellectual who would get off on Jaynes' book.
"Look what you did to my shirt."

I'm sorry if I'm stating the obvious, but I believe this film is inspired by the work of John C Lilly. Dolphin consciousness. Flotation tanks.

GEB is good. So is The Origin of Consciousness in the Breakdown of the Bicameral Mind, by Julian Jaynes. (Published in 1976. Jessup would undoubtedly have been aware of it.)
"Look what you did to my shirt."

Try tackling "Goedel, Escher, Bach," by Douglas Hofstadter. Hofstadter is knowledgable in several disciplines, with a focus in artificial intelligence. It's a dense read, and long, but you don't have to read it straight through. Find the chapters about the brain and read those. In particular, read the chapter "Ant-eater's Fugue," and the following chapter. The book covers more than your question, but your question is at the heart of it. He's asking, "What is self-awareness? What makes us a self?" It's a beep

Fascinating article, tron. ("Holographic universe" will now be part of my vocabulary.) Also very relevant when you note that "holographic" aspects of the isolation tank in the film: it almost becomes an externalization of Jessup's mental lanscape.
1.) The Lord loves a working man.
2.) Don't trust whitey.

Check out this
http://www.redicecreations.com/specialreports/2006/01jan/holographic.html
page on the theory of the Holographic Universe. It gives a good high level view on the theory and does explain some interesting phenomena one may experience with having an experience and also covers our brains amazing ability to interpret frequency (sound/light/touch/ect) and remember and recall these events immediately even decades later. It's a fascinating read.

You could also ask, "what's the difference between a cell and a finger"?
In fact, very little. But I guess the real difference occurs once there is a brain that's where consciousness comes from. Somehow all the synapses create thoughts, and allow for emotions and a certain understanding of time and sequential consequences. Monkeys already know how to create tools which proves that they have an idea of cause and effect which allows them to project an action into the future. I guess all "higher" animals have a certain consciousness I'm thinking of porpoises, whales, elephants and the great apes.
Perhaps mammals in general? But then, a spider builds a web (like a tool) and must either do it totally instinctively or somehow know that the result will be "dinner".
Don't know if anything I've said here helps, but at least it's worth thinnking about

I just finished watching the film and as someone interested in 'experiences' I found this film fascinating from the outset.
In the film we are told about the 'unborn soul' and the regression of life.
In the scene where Jessup 'regresses' to a primitive being I got the idea that he had reached a point where the idea of a 'soul' was first 'created'.
There are scenes where Jessup describes the beings he was hallucinating about and he is quite descriptive i.e. 'the didn't use their knuckles to walk' etc. My opinion is that the film was trying to point out that this was a period in the evolution of humans where the idea of a soul and a self awareness was coming about.
Although I enjoyed the film I was still unsure as to Jessup's full intentions towards the end..was he just trying to push the limits of human conscience or was it something more specific.
Discussion would be most welcome
"When all are one and one is all, to be a rock and not to roll.."

"Self awareness counts for everything."
Indeed. And I know few people today with the convicted self-awareness of an Ed Jessup.
"Look what you did to my shirt."

Self awareness counts for everything. It is the whole thing. And, ponder this: "We are all made up of stardust. When you look up into the sky at the stars, realize that you are the universe looking at itself," Carl Sagan.

Thanks for writing this. Outstanding breakdown and really insightful.

i'm not a believer but i think you have mistaken at one point. Religions didn't "start" at sometime. They say that religion is here because god want human to pull themself together. kind of a warning and manual. they always exists but we moronheads just can't have it so it sent those books

Good discussion. Too bad the thread is so neglected.
In response to the OP (if you're still out there): I think AS touches on this idea but also turns it inside out. Jessup regresses, not only to a Cro Magnon or whatever, but ultimately to a shapeless molecular mass and finally to a single undifferentiated cell (a stem cell, I suppose). The point is that he loses his human identity in the process, or at least the dormant "junk" DNA in his cells which is ancient and pre-human become activated and switch off his human identity. And the only way his humanity can be reactivated is through Emily.
"Look what you did to my shirt."