Charles asked:

My philosophy teacher says there is no tv in your head. I believe there is because how do we picture past things like my 1st grade teacher vividly.

Answer by Craig Skinner

I’d like to argue, that I’m afraid your philosophy teacher is right.

The inside of your head is cramped and pitch dark. There is nobody in there to look at anything. And no screen to be looked at.

The confusion arises from the sense-datum representational theory of perception. According to this, when I look at, say, a tree, a representation of the tree is formed in my mind. So far, so good, and true in my view. But the next step goes wrong. This representation is regarded as a picture (sense datum), and THAT is what I am looking at. Naturally, to see this picture in my head (on a tv screen if you like), a viewer is needed. So the little viewer in my head looks at the picture and sees the tree. But how does THIS viewer see it. By forming a little picture in his little head, and an even tinier viewer therein looks at that picture. And so on. An infinite regress of ever-tinier little men (homunculi) inside ever-tinier heads looking at ever-tinier pictures. Clearly absurd.

When you look at a tree, it is YOU who sees it, and what you see is the TREE, not some picture in your head. The way you do this is by converting the features of the tree, encoded in the pattern of light reaching your eyes, into patterns of electrical impulses going from eye to brain which result in a pattern of nerve cell activation in the brain corresponding to YOU seeing the tree. There are no non-physical entities in your head which must themselves be viewed. You simply see ‘treely’ as it were. Similarly, when you look at a post box, you don’t look at a red image in your head. You just see ‘redly’.

You can indeed picture your 1st grade teacher vividly. When you experienced her presence live, a particular pattern of brain activity corresponding to your seeing (and hearing) her was set up. This pattern faded as soon as a new one took its place in your consciousness. But not before the pattern was transferred to the hippocampus (the brain area for long-term memory) and laid down long-term partly as continuing activity patterns, partly as molecular changes. You can access these memories, and when you do, the pattern of brain activity you had when seeing the teacher is replicated so that you seem to see her now. Not an exact replication, because, although the recall is vivid, you know she is not really standing before you.

What I am advocating is indirect (representational) realism as an account of perception, but an ‘adverbial’ rather than a ‘sense datum’ view. You should read about these, as well as the direct realism and phenomenological accounts of perception (both incorrect in my view).