Posted by Estella on September 3, 2006, at 6:45:57
In reply to Guess I couldn't stay away completely..., posted by finelinebob on September 3, 2006, at 1:45:22
> ROY G BIV, Estlla, ROY G BIV ...
Yeees. Multi-guess psychophysics is coming back to me :-)
> ... or VIB G YOR, since they got it backwards.
Well now, that just don't sound pretty ;-)
> Mathemagically, it's prolly pretty simple. You have A as your lowest detectible count or just set it to 1, black being 0. You have Z has the highest detected count. Violet light has a short wavelength (low number), red a long wavelength (high number). Match your lowest violet to A, your highest red to Z, and let the computer figure out the rest in-between.Okay. Thanks. I didn't know that. Though I'm worried about the computer 'figuring out' stuff...
> Of course, the visible spectrum expressed that way is a linear progression. If your theory behind what you're studying suggests a non-linear response, then you have to get tricky.Woo hoo!!! Thats what I was thinking. Now hang on. I f*cked up my word for the week (abberant) so maybe I f*cked up my math for the week too.
Linear (a):
Non linear: (the restWoo hoo. Also... Ah... Thats what log is for ;-)
Do they use linear or non linear for colour distributions on the scan do you know?
> Say I'm doing a PET scan of a stroke patient trying to read something and I get lots of yellow and red (woohoo!) in the visual cortex
So they are processing visual stimuli...
> but blue to violet to black wherever it is in our brains that turns those visual stimuli into language and then meaning ... uh oh.
Ah.
Though sometimes different people have different localisations. So (for example) if you have damage to the left hemisphere as a fetus then you can develop language production and comprehension (for example) in the right hemisphere.
> Then again, I got this pre-chemo scan of a patient with a tumor somewhere, all nasty bright yellow and red (boo!)
High activity at tumor sites?
Are lesions different?The colour stuff was interesting, thanks for that :-)
poster:Estella
thread:680731
URL: http://www.dr-bob.org/babble/20060901/msgs/682586.html