Attentional Bias Experiment

Back

Attentional Bias Experiment

Author	Message
Dave	Dave posted 11 Years Ago ANSWER Post Details Share Post
Group: Administrators Posts: 13K, Visits: 108K	> 1. How do you code such that the posttrial pause averages to 500 ms but ranges from 250 - 750 ms? /posttrial attributes and the like accept expressions. You need to program an expressions that draws from a distribution that has the properties you want (cf. https://www.millisecond.com/forums/Topic8431.aspx for an elaborate example). > 2. Is it possible to display a stimuli for 50 ms? Yes, but if 50ms can be achieved will primarily depend on your display's refresh rate. A display running at 100Hz has a 10ms refresh cycle, i.e. 50 frames will give you approx. 50ms. A display running at 50Hz has a 20ms refresh cycle. Obviously, there is no way to achieve 50ms with that (2 frames = 40ms; 3 frames = 60ms). > 3. How do you program so that both the position of the stimuli (right/left or top/bottom) and the probes (A or H) are randomized? There are dozens of ways to approach this and as with /posttrialpause, /position attributes accept expressions. As your question stands, it is ill-defined: "randomizing" can mean any number of things (think coin flips vs. drawing from a deck of n cards) and it is not possible to give a sensible answer without knowing your intentions and exact parameters. Since you are new to Inquisit, I would also strongly recommend you (a) start by working through the tutorials included in the documentation (if you haven't done so already) and (b) study a selection of scripts available from the task library (which included dot-probe-type tasks).
	Reply Like 33
mchu01	mchu01 posted 11 Years Ago Topic Details Share Topic
Group: Forum Members Posts: 4, Visits: 97	Hi, I am new to Inquisit and have several general questions. I am trying to set up a dot-probe like task to measure attention with pictures. The task would either have the picture pairs right or left of the fixation or top or bottom of the fixation. Instead of indicating the location of the probe, participants would have to indicate either for example an A or H that appears behind the probe. 1. How do you code such that the posttrial pause averages to 500 ms but ranges from 250 - 750 ms? 2. Is it possible to display a stimuli for 50 ms? 3. How do you program so that both the position of the stimuli (right/left or top/bottom) and the probes (A or H) are randomized? Thanks so much!
	Reply Like 30