Moving dots direction change

Support
1

Hi Chris,
We’re working on an experiment using the moving dots where the dots go from stationary to moving on each trial, with varying directions and speeds of movement. The issue is that the whole dot field rotates when the direction of movement changes. To account for this, we set the direction at the beginning of each trial for the stationary condition and then just increase the speed- this avoids a rotation between the stationary and moving condition. However, the rotation is still apparent between trials. Is there any way to change the plugin so that the rotation of the dot field doesn’t depend on the direction of movement to avoid these big changes in dot position at the start of each trial?
Thanks,
Lindsey.

4

Hi Lindsey,

Do you need the dots to be on the display at all times? If you could hide them briefly before changing direction, it would make the rotation much less obvious. Also, you’d have the opportunity to regenerate all the dots at new, random locations, which would eliminate the rotation entirely.

If you do need the dots to remain on the display and just change direction as needed, then yes, I can change the plugin to do that. Since it would be a backward-incompatible change, you would need to enable it explicitly, probably via a new parameter.

Cheers,
Chris

5

Hi Chris,

We’re presenting trials fairly rapidly (1s on/off) so it would be best to avoid on/off transients.

Having a new parameter that toggles the direction control is fine.

Thanks,

Lindsey.

6

OK, I’ll try to get this done in the next couple weeks.

Thanks,
Chris