Millisecond Forums » Millisecond Forums » Inquisit 6 » Lexical Decision Task - How to jitter Fixationcross

Lexical Decision Task - How to jitter Fixationcross

DannyPilgrim — Tue, 24 Nov 2020 00:37:29 GMT

Hello everyone!

I have a question: Is there any way to jitter the fixationcross within a range of 0ms-1000ms?
This is the current Trialcode:

<trial T1>
/ontrialbegin = [
values.condition = 0;
values.congruency = 0;
]
/ correctresponse = ("2") / beginresponsetime = 1500
/ validresponse = ("2", "8")
/ trialduration = 3000
/ stimulustimes = [0=Fixationcross; 1000=clearscreen; 1700=mask; 500=end; 1500=sausage]

I hope you understand my issue!

Thanks.

RE: Lexical Decision Task - How to jitter Fixationcross

DannyPilgrim — Tue, 24 Nov 2020 00:37:29 GMT

+x[quote]

[b]Dave - 11/23/2020[/b]
+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
+x[quote]

[b]Dave - 11/23/2020[/b]
+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
Hello everyone!

I have a question: Is there any way to jitter the fixationcross within a range of 0ms-1000ms?
This is the current Trialcode:

<trial T1>
/ontrialbegin = [
    values.condition = 0;
    values.congruency = 0;
]
/ correctresponse = ("2") / beginresponsetime = 1500
/ validresponse = ("2", "8")
/ trialduration = 3000
/ stimulustimes = [0=Fixationcross; 1000=clearscreen; 1700=mask; 500=end; 1500=sausage]

I hope you understand my issue!

Thanks.
[/quote]

> I hope you understand my issue!

No, you need to be more specific. By "jitter[...] the fixationcross within a range of 0ms-1000ms" do you mean the fixation cross's on-screen duration or its onset?

In addition, please clarify the trial's intended stimulus timing. The out-of-order notation in your /stimulustimes is very confusing. Spell out exactly when you want each stimulus presented in relation to what.

[/quote]

Thank you for your quick answer, Dave!

My intention is to randomize the onset time of the Fixationcross. It's on-screen duration should remain 500ms.
All trials should look like this:

Fixationcross (onset = random between 0ms (immediately when the trial starts) and 1000ms (1 second after the trial started), on-screen duration = 500ms)
Prime (onset = immediately after Fixationscross, on-screen duration = 500ms)
Clearscreen (onset = immediately after Prime, on-screen duration = 500ms)
Target (onset = immediately after Clearscreen, on-screen duration = 200ms)
Mask/ Responsewindow (onset = immediately after Target, on-screen duration = 1300ms)
Right now the trialduration is 3000ms without the jittered Fixationcross.

Do you need more information?

Thanks for your help!

[/quote]

That should be clear enough. Any implementation of that would look along the following lines:

<parameters>
/ fixationduration = 500
/ primeduration = 500
/ clearduration = 500
/ targetduration = 200
/ maskduration = 1300
</parameters>

<values>
/ fixationonset = -1
</values>

<trial example>
/ ontrialbegin = [
    trial.example.resetstimulusframes();
    values.fixationonset = round(rand(0, 1000));
    trial.example.insertstimulustime(text.fixationcross, values.fixationonset);
    trial.example.insertstimulustime(text.prime, values.fixationonset + parameters.fixationduration);
    trial.example.insertstimulustime(clearscreen, values.fixationonset + parameters.fixationduration + parameters.primeduration);
    trial.example.insertstimulustime(text.target, values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration);
    trial.example.insertstimulustime(text.mask, values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration + parameters.targetduration);
]
/ stimulustimes = [0=clearscreen]
/ beginresponsetime = values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration
/ trialduration = values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration + parameters.targetduration + parameters.maskduration
...
</trial>

<text fixationcross>
/ items = ("+")
</text>

<text prime>
/ items = ("prime")
</text>

<text target>
/ items = ("target")
</text>

<text mask>
/ items = ("mask")
</text>

[/quote]

Thank you very much! That helped a lot!

RE: Lexical Decision Task - How to jitter Fixationcross

Dave — Mon, 23 Nov 2020 18:54:38 GMT

+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
+x[quote]

[b]Dave - 11/23/2020[/b]
+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
Hello everyone!

I have a question: Is there any way to jitter the fixationcross within a range of 0ms-1000ms?
This is the current Trialcode:

<trial T1>
/ontrialbegin = [
values.condition = 0;
values.congruency = 0;
]
/ correctresponse = ("2") / beginresponsetime = 1500
/ validresponse = ("2", "8")
/ trialduration = 3000
/ stimulustimes = [0=Fixationcross; 1000=clearscreen; 1700=mask; 500=end; 1500=sausage]

I hope you understand my issue!

Thanks.
[/quote]

> I hope you understand my issue!

No, you need to be more specific. By "jitter[...] the fixationcross within a range of 0ms-1000ms" do you mean the fixation cross's on-screen duration or its onset?

In addition, please clarify the trial's intended stimulus timing. The out-of-order notation in your /stimulustimes is very confusing. Spell out exactly when you want each stimulus presented in relation to what.

[/quote]

Thank you for your quick answer, Dave!

My intention is to randomize the onset time of the Fixationcross. It's on-screen duration should remain 500ms.
All trials should look like this:

Fixationcross (onset = random between 0ms (immediately when the trial starts) and 1000ms (1 second after the trial started), on-screen duration = 500ms)
Prime (onset = immediately after Fixationscross, on-screen duration = 500ms)
Clearscreen (onset = immediately after Prime, on-screen duration = 500ms)
Target (onset = immediately after Clearscreen, on-screen duration = 200ms)
Mask/ Responsewindow (onset = immediately after Target, on-screen duration = 1300ms)
Right now the trialduration is 3000ms without the jittered Fixationcross.

Do you need more information?

Thanks for your help!

[/quote]

That should be clear enough. Any implementation of that would look along the following lines:

<parameters>
/ fixationduration = 500
/ primeduration = 500
/ clearduration = 500
/ targetduration = 200
/ maskduration = 1300
</parameters>

<values>
/ fixationonset = -1
</values>

<trial example>
/ ontrialbegin = [
    trial.example.resetstimulusframes();
    values.fixationonset = round(rand(0, 1000));
    trial.example.insertstimulustime(text.fixationcross, values.fixationonset);
    trial.example.insertstimulustime(text.prime, values.fixationonset + parameters.fixationduration);
    trial.example.insertstimulustime(clearscreen, values.fixationonset + parameters.fixationduration + parameters.primeduration);
    trial.example.insertstimulustime(text.target, values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration);
    trial.example.insertstimulustime(text.mask, values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration + parameters.targetduration);
]
/ stimulustimes = [0=clearscreen]
/ beginresponsetime = values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration
/ trialduration = values.fixationonset + parameters.fixationduration + parameters.primeduration + parameters.clearduration + parameters.targetduration + parameters.maskduration
...
</trial>

<text fixationcross>
/ items = ("+")
</text>

<text prime>
/ items = ("prime")
</text>

<text target>
/ items = ("target")
</text>

<text mask>
/ items = ("mask")
</text>

RE: Lexical Decision Task - How to jitter Fixationcross

DannyPilgrim — Mon, 23 Nov 2020 18:28:25 GMT

+x[quote]

[b]Dave - 11/23/2020[/b]
+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
Hello everyone!

I have a question: Is there any way to jitter the fixationcross within a range of 0ms-1000ms?
This is the current Trialcode:

<trial T1>
/ontrialbegin = [
values.condition = 0;
values.congruency = 0;
]
/ correctresponse = ("2") / beginresponsetime = 1500
/ validresponse = ("2", "8")
/ trialduration = 3000
/ stimulustimes = [0=Fixationcross; 1000=clearscreen; 1700=mask; 500=end; 1500=sausage]

I hope you understand my issue!

Thanks.
[/quote]

> I hope you understand my issue!

No, you need to be more specific. By "jitter[...] the fixationcross within a range of 0ms-1000ms" do you mean the fixation cross's on-screen duration or its onset?

In addition, please clarify the trial's intended stimulus timing. The out-of-order notation in your /stimulustimes is very confusing. Spell out exactly when you want each stimulus presented in relation to what.

[/quote]

Thank you for your quick answer, Dave!

My intention is to randomize the onset time of the Fixationcross. It's on-screen duration should remain 500ms.
All trials should look like this:

Fixationcross (onset = random between 0ms (immediately when the trial starts) and 1000ms (1 second after the trial started), on-screen duration = 500ms)
Prime (onset = immediately after Fixationscross, on-screen duration = 500ms)
Clearscreen (onset = immediately after Prime, on-screen duration = 500ms)
Target (onset = immediately after Clearscreen, on-screen duration = 200ms)
Mask/ Responsewindow (onset = immediately after Target, on-screen duration = 1300ms)

Right now the trialduration is 3000ms without the jittered Fixationcross.

Do you need more information?

Thanks for your help!

RE: Lexical Decision Task - How to jitter Fixationcross

Dave — Mon, 23 Nov 2020 17:20:04 GMT

+x[quote]

[b]DannyPilgrim - 11/23/2020[/b]
Hello everyone!

I have a question: Is there any way to jitter the fixationcross within a range of 0ms-1000ms?
This is the current Trialcode:

<trial T1>
/ontrialbegin = [
values.condition = 0;
values.congruency = 0;
]
/ correctresponse = ("2") / beginresponsetime = 1500
/ validresponse = ("2", "8")
/ trialduration = 3000
/ stimulustimes = [0=Fixationcross; 1000=clearscreen; 1700=mask; 500=end; 1500=sausage]

I hope you understand my issue!

Thanks.
[/quote]

> I hope you understand my issue!

No, you need to be more specific. By "jitter[...] the fixationcross within a range of 0ms-1000ms" do you mean the fixation cross's on-screen duration or its onset?

In addition, please clarify the trial's intended stimulus timing. The out-of-order notation in your /stimulustimes is very confusing. Spell out exactly when you want each stimulus presented in relation to what.