Hi all,
I am working on a BOLD task for an older adult population where I would like to parse the perceptual/attention allocation components of the task trials from the decision-making/response components. The task involves a jittered inter-stimulus crosshair, followed by 500 ms presentation of a stimulus, followed by a 1000ms mask, and a 3s response probe screen. Participants view the stimulus, remember the location and type of items present, and then must decide whether the probe screen is the same or different from what they saw in the stimulus. Currently, we are jittering the inter-stimulus cross hair screen with an average ISI of 4s (using optseq), but we would also like to jitter the mask to allow us to parse our components of interest. We are concerned that a long delay in the mask prior to the probe screen would introduce a significant working memory component to the task. Does anyone have advice on this issue? The slow 4s ISI is primarily chosen to facilitate task performance in our older population, but could we use a more rapid ISI for the mask prior to the probe response screen to limit the working memory load (randomizing across trials of different difficulty levels)?
I appreciate any advice.
Best,
Adam
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