I’ve created a program that runs an interleaved staircase where a gradient (sin; gauss) is flashed upon the screen at a particular angle. The ‘BaseGrating’ is at a .05 opacity, so it should appear below the visual threshold.
Following the invisible base gradient, a second gradient (‘ChangeGrating’) is flashed at a different angle, starting value is 45 degree difference on either side from the preceding base gradient.
The participant must then select either the right or left arrow key, in response to whether the ChangeGrating was clockwise or counterclockwise, respectively, from the base gradient. If they answer correctly, they get a high tone/green plus sign; and if wrong–a low tone/red minus symbol.
As the participant answers correctly, the angles of the ChangeGrating works its way inwards towards the angle of the angle of the base gradient. If they answer incorrectly, the angle should go back outward. (A design I’m assuming you may be familiar with)
Here are my issues:
I am still not sure what to make my stepSizes. What is the difference between having [2,2,2,2,2,1] and [8,6,6,4,4,2,2,1] ? Is it that the prior goes down in steps at a consistent pace, while the latter decreases exponentially? Also, what is the difference between using decimal numbers, for example, [0.8,0.6,.0.4,0.2] versus whole numbers, [8,6,4…]? Finally, what is the difference between skipping values [9,7,5…] and not skipping values [9,8,7,6]?
This interleaved system works fine when my base gradient is at 0 degrees. However, when I set the base gradient to say, 60 or 90 degrees, it appears that right answers are not triggering the narrowing effect. It seems to just be changing degrees at random. Or I will get the effect where the counterclockwise angles will narrow but the clockwise side does not.
Here is what I am wondering: If my startVal is 45 degrees, and my base gradient is zero, then it narrows down appropriately. If my base gradient is at 90 degrees, and I still wanted a 45 degree difference, then would I make my startVal 135 degrees for it to narrow down on the 90 degree marker in the same fashion as it does for 0 degrees?
Attached are screenshots of the settings for the experiment.