Choices, choices....

I received an email today from my future boss informing me that another research project proposal got granted. Two months ago when we had our first talk about my future possibilities as a PhD student in his lab, this proposal was only just submitted and he asked me my preference in research projects; the already granted project investigating "conscious visual perception" or the submitted one "spatial abstraction and categorisation" (in simple words "controlling what you see" and "spatial orientation"). Back then I thought both projects sounded like interesting and fun. Both used similar techniques (fMRI, electrophysiology and psychophysics). CVP had a larger international outreach, SAC a more concrete aim. I told him I did not really have a preference and I got the job for the CVP-project. All good.

Well today I got this email telling me the SAC-project got granted as well and if I would be willing to switch to the SAC so someone else could start on CVP right away (since I will only be able to start in february or march). Now I don't know what to do. Since I got really enthusiastic about the CVP over the last months I think I prefer not to switch, but is a first thought the right one? I should read in on the SAC and see if my first thought lingers on. For the type of work it wouldn't matter, same methods (other stimuli though), same lab, same pay.... It's the context that makes the difference; what ultimate goal do I consider more attractive to work on for 4 years, do I want to work in a biology-physics context or a biology-psychology context, do I want to flirt with a scientific approach to an age old philosophic problem or do I want to work more applied, is the collaboration with Harvard/Princeton/Salk/Sydney that important to me?

I realize that this is a luxury problem. I didn't graduate yet, still I'm sure of a nice PhD-student position and I'm nagging on about how hard it is to choose between two projects... But still it decides what I'll be doing for four years and what I'll get a PhD in which might be important for the rest of my scientific career.. Sigh, and I don't even know why I am posting this, it's not like any of you will some up with the solution (although I dare you to!). I have to figure this one out myself...