Varying the duration of a jpeg image
Posted: Sun Mar 03, 2013 2:47 pm
Hi,
I am in the process of creating an experiment which measures responses to various targets against photographic backgrounds. I am using a Spatial 2AFC procedure. For the targets I am using a Gabor visual stimulus. The backgrounds are jpeg images. I want to vary the duration of the target stimulus so have set the duration of the Gabor to [duration]/1000 and the duration of the background image to .3secs. This seems to work perfectly.
However, I would also like the target and the background to appear and disappear together - but if I also set the duration of the background to [duration]/1000, the image is no longer visible. What I get in this case is the target against a plain black background.
I would be most grateful for any advice.
Many thanks in advance.
I am in the process of creating an experiment which measures responses to various targets against photographic backgrounds. I am using a Spatial 2AFC procedure. For the targets I am using a Gabor visual stimulus. The backgrounds are jpeg images. I want to vary the duration of the target stimulus so have set the duration of the Gabor to [duration]/1000 and the duration of the background image to .3secs. This seems to work perfectly.
However, I would also like the target and the background to appear and disappear together - but if I also set the duration of the background to [duration]/1000, the image is no longer visible. What I get in this case is the target against a plain black background.
I would be most grateful for any advice.
Many thanks in advance.