implement new stimuli in the stim generator

[mbreiser]

Looming Patterns — Generate looming stimuli with constant velocity or exponential approach profiles
Reverse-phi -- delete current implementation and review papers to get it right, and simple.

and then done, port the implementation to webDisplayTools

[mbreiser]

for reverse-phi @leburnett shared:
the script used to make the reverse phi stimuli can be found here. It uses the function ShiftMatrix which can be found here. You can find the actual patterns here.

When I was making the different versions of the reverse phi patterns I was simply modifying the parameters in this script and then would save the pattern with an appropriate name. The current parameters that are saved are for making a gs_val = 2 version of the reverse phi but the pattern used in the p27 screen protocol is pattern 60 which is a gs_val =3 pattern (Allows for pixel intensities between 0-7. Background value = 3, off = 0 and on = 7). The bars are 16 pixels wide (same as 60 deg gratings) and they move by 8 pixels each frame. The pattern inverts contrast every frame.

This was the protocol I used to test different versions of the reverse phi stimulus. I've attached a screenshot of the turning and centring responses to each stimulus. I've highlighted the condition that was then used in the p27 protocol.