Refreshing 'noise' in a static stimulus
Posted: Wed Sep 02, 2015 3:01 pmHi
I am using contrast reversing 2D pink noise in my stimulus, but would like the pattern of the noise to refresh after each reversal (or at all!), but I can't figure out how to do this. The location of the stimulus moves position using the [TIME] variable, and I wondered if maybe [TIME] can be used anywhere else to indicate that it should refresh at a particular rate?
For now I've tried to create the illusion of 'fresh noise' by having multiple duplicates of the stimulus within the contrast reversal event, but it causes large delays at the start of each stimulus cycle while it's generated, and the stimulus needs to be quickly and reliably produced as it's for fMRI presentation.
Any ideas?
Thanks!
Lauren
I am using contrast reversing 2D pink noise in my stimulus, but would like the pattern of the noise to refresh after each reversal (or at all!), but I can't figure out how to do this. The location of the stimulus moves position using the [TIME] variable, and I wondered if maybe [TIME] can be used anywhere else to indicate that it should refresh at a particular rate?
For now I've tried to create the illusion of 'fresh noise' by having multiple duplicates of the stimulus within the contrast reversal event, but it causes large delays at the start of each stimulus cycle while it's generated, and the stimulus needs to be quickly and reliably produced as it's for fMRI presentation.
Any ideas?
Thanks!
Lauren