Well, can you?

I can't do it for toffee.

I'm reading Derren Brown's Tricks of the Mind and in one section of the book he asks you to think of something that really excites you. Assuming you picture something in your mind as a result he then asks you to hold the image, make it larger and more colourful. Later on he's talking about manipulating it further.

I can only hold an image of anything for about a second before it seems to morph into something else and then something else ad infinitum and I have no control over this. At times it's quite entertaining because I just close my eyes and it's a little bit like watching a continually segueing sophisticated film/cartoon but at others like now when I need to focus it's pretty annoying.

So, can you other souls hold images and move them around or have you got some ridiculous jumble-brain like me?