Millisecond Forums » Millisecond Forums » Inquisit 6 » Incorrect Number of Trials

Incorrect Number of Trials

charsiubhau — Tue, 18 Oct 2022 17:25:18 GMT

Hi there,

I want to have 98 experimental trials for the each of the experimental trials for the nback (2 keys) followed by slider trial. However, I noticed in my output that they are not always 98. The sequence is as follows (not including slider trial):
- 1back = 98 experimental trials
- 2back = 99 experimental trials
-3back = 100 trials
Is it possible to have the 1back, 2back, and 3back all have 98 experimental trials? My code for trials is below, please let me know if you need my full script or any additional information. I'd appreciate any help!
1 = start;
2 - 98 = noreplace(nontarget, nontarget,target);
99 = slidertrial.nbackperception;

RE: Incorrect Number of Trials

charsiubhau — Tue, 18 Oct 2022 17:25:18 GMT

+x[quote]

[b]Dave - 10/18/2022[/b]
+x[quote]

[b]charsiubhau - 10/18/2022[/b]
Here is my code!
[/quote]

I think you're mistakenly counting the start trials, of which there obviously must be a different number depending on the N-level.

At N=1, the block must begin with one start trial. Only the second trial can be an experimental trial, since otherwise there is no stimulus presented one trial back (1-back).
At N=2, the block must begin with two start trials. Only the third trial can be an experimental trial, since otherwise there is no stimulus presented two trials back (2-back).
At N=3, the block must begin with three start trials. Only the fourth trial can be an experimental trial, since otherwise there is no stimulus presented three trials back (3-back).

[/quote]

Hi Dave,

This makes a lot of sense, thank you so much!

RE: Incorrect Number of Trials

Dave — Tue, 18 Oct 2022 15:28:41 GMT

+x[quote]

[b]charsiubhau - 10/18/2022[/b]
Here is my code!
[/quote]

I think you're mistakenly counting the start trials, of which there obviously must be a different number depending on the N-level.

At N=1, the block must begin with one start trial. Only the second trial can be an experimental trial, since otherwise there is no stimulus presented one trial back (1-back).
At N=2, the block must begin with two start trials. Only the third trial can be an experimental trial, since otherwise there is no stimulus presented two trials back (2-back).
At N=3, the block must begin with three start trials. Only the fourth trial can be an experimental trial, since otherwise there is no stimulus presented three trials back (3-back).

RE: Incorrect Number of Trials

charsiubhau — Tue, 18 Oct 2022 14:11:41 GMT

Here is my code!

RE: Incorrect Number of Trials

charsiubhau — Tue, 18 Oct 2022 14:08:26 GMT

+x[quote]

[b]charsiubhau - 10/18/2022[/b]
Hi there,

I want to have 98 experimental trials for the each of the experimental trials for the nback (2 keys) followed by slider trial. However, I noticed in my output that they are not always 98. The sequence is as follows (not including slider trial):
- 1back = 98 experimental trials
- 2back = 99 experimental trials
-3back = 100 trials
Is it possible to have the 1back, 2back, and 3back all have 98 experimental trials? My code for trials is below, please let me know if you need my full script or any additional information. I'd appreciate any help!
1 = start;
2 - 98 = noreplace(nontarget, nontarget,target);
99 = slidertrial.nbackperception;
[/quote]

I just noticed that it increases the practice trials by one as well when I want them to remain at 10 practice trials for all levels. The sequence is as follows:
- 1back = 10 practice trials
- 2back = 11 practice trials
- 3back = 12 practice trials