Hi,

I am about to run the AAT and have two quick questions:

1. Can you tell me if the value of the joystick threshold has any effect on the results recorded?  Within the library script, it is set at 50 by default, but I’m not sure what this means – is itthat a response will only be recorded if the joystick is extended to ‘50’ (Iassume a midway movement), but that the response times are still recorded from when theparticipant first touches the joystick (values.RT), and when it is fully extended (values.CompleteRT)?  I am using a Logitech Attack 3.
2. I want to reduce the size at which the image first appears - I know I can do that by changing the startheight ratios as follows (from .5 to .45), but I just want to make sure that doesn't effect how the script runs (times recorded etc.)



Thanks very much.

Rebecca

Re. #1: You can think of the joystick threshold as a kind of sensitivity setting, i.e. how pronounced the movement must be to be considered a response. At very low settings, the joystick may feel "fickle," i.e. even extremely minimal and involuntary movements could result in change of direction errors, for example. At very high settings, on the other hand, a given joystick may seem too unresponsive (and the "zoom" animation in the AAT would appear to be much cruder / less smooth). You'll want to find a reasonable middle ground for your joystick, i.e. something not so fickle as to register minimal / involuntary movements as errors, but responsive to voluntary movements. A value of 50 may be too high, I'd try values between 20 and 30.

Re. #2: Reducing the startheight ratio should have no detrimental effect.

Hope this helps.