harvesting for cerebral high

i am growing bagseed i think it is a sativa indica mix but the main cola is mostly milky colored pistils and the tops of the sideshoots pistils are about 50% red hairs. i thought the main cola matured faster but i do have 2 150 watt cfls 2 inches away from it. but i want a cerebral high and was wondering when i should harvest i am in the 7th week of flowering. also do you loose any yield when you harvest early for cerebral instead of narcotic high

Yield would not differ so much that it should be a factor. Get a scope and check the FAQ's for the trich chart.

don't go by the color of the hairs, cuz different strains mature and color differently...

go to radioshaq and buy a little pocket microscope for 10bucks and check the trichromes... that'll give you a true indication of how the buds are ripening...
30-50% amber more cerebral
75% amber more couchlock

trichs go from clear, to cloudy, to amber... btw

alright thanks guys ill be going to get that 2morrow

LJIan covered it. Using the scope takes some getting used to, though. Move the branch just a little and you're now looking at a completely different section of the bud and will have to re-zoom and re-focus (a pain, but one of those labors that make harvest time all-the-more rewarding). Some people like to cut portions of trich-bearing leaves off and check those.

Here is a link to the trich chart: Link