"What exactly do people mean when they speak of the self?
Its defining characteristics are fourfold.
First of all, continuity.
You've a sense of time, a sense of past, a sense of future.
There seems to be a thread running through your personality, through your mind.
Second, closely related is the idea of unity or coherence of self.
In spite of the diversity of sensory experiences, memories, beliefs and thoughts, you experience yourself as one person, as a unity.
So there's continuity, there's unity.
And then there's the sense of embodiment or ownership - yourself as anchored to your body.
And fourth is a sense of agency, what we call free will, your sense of being in charge of your own destiny.
These different aspects of self can be differentially disturbed in brain disease, which leads me to believe that the self really isn't one thing, but many.
Just like love or happiness, we have one word but it's actually lumping together many different phenomena.
For example, if I stimulate your right parietal cortex with an electrode (you're conscious and awake) you will momentarily feel that you are floating near the ceiling watching your own body down below.
You have an out-of-the-body experience.
The embodiment of self is abandoned.
One of the axiomatic foundations of your Self is temporarily abandoned.
And this is true of each of those aspects of self I was talking about.
They can be selectively affected in brain disease."
