Counting time between photo shown on screen and some predefined keyboard button pressed

Seems like I need to rephrase my previous question and instead of giving a script I'd appreciate getting one - need to count time between a photo is shown (from the hard drive) until a predefined key is pressed. For example, present a face photo with one eye shut. If it is left eye press l, register time and continue, if its right eye press r, register, continue. Also mark if the key pressed was correct or not. Many thanks in advance. R

Answer 1

[Sean de Wolski]

You could use:

tic/toc
cputime
etime

etc..

[Ron Seligmann]

My main problem is to get a response from the keyboard from a predefined key...