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Programing 2 task N-Back

CAA — Thu, 10 Dec 2015 16:27:26 GMT

Good afternoon,

I am trying to program the 2 task N-back to have two word lists, list A and list B. During the task, I want the presentation of words to be random, pulling from both lists. My goal is to compare task performance of list A to list B, so I would like data for each list to be separate.

My questions are: How can I program the task so that I have two word lists presented at random to the participant? And how can I get task performance data for each lists separately?

Thanks.
CA

RE: Programing 2 task N-Back

Dave — Thu, 10 Dec 2015 16:27:26 GMT

> Instead of one list of shapes, I want two different lists: list A and list B.
> During the task, I want items be randomly selected from either lists.

This is still a very vague description. It also isn't workable as it stands because it fails to consider the interdependencies in the stimulus sequence. To be able to compare the two "lists" in a valid fashion, you'd need an equal amount of target and non-target trials per list. That's a complex constraint. See https://www.millisecond.com/forums/FindPost17427.aspx for a similar example and why that's problematic.

If comparing performance between list A and B is the primary goal, then doing two separate N-backs (one only using item list A, the other one using only item list B) would be much more straightforward and not hampered by validity issues.

RE: Programing 2 task N-Back

CAA — Thu, 10 Dec 2015 15:37:28 GMT

Good afternoon,

Thank you for your reply.

I want to program a task that works exactly like the SingleTask2Keys task. Instead of one list of shapes, I want two different lists: list A and list B.

During the task, I want items be randomly selected from either lists.

Then, I want to collect raw data of total hits, and total false hits. Then, total hits and false hits of items of List A, and total hits and false hits of items of List B.

Cheers.

RE: Programing 2 task N-Back

Dave — Thu, 10 Dec 2015 12:53:27 GMT

I'm afraid the description in your post is much too vague to give a sensible response. Could you flesh it out in sufficient detail, please?

Beyond that, it might be instructive to work through the Dual-Task N-back procedures available at https://www.millisecond.com/download/library/NBack/

Those use stimuli in two different *modalities* (auditory and visual) instead of two different word lists, but might nonetheless give you a number of ideas about how to potentially approach this.