Millisecond Forums » Millisecond Forums » Inquisit 6 » fMRI timing precision

fMRI timing precision

troyh — Tue, 02 Nov 2021 22:14:32 GMT

Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.

RE: fMRI timing precision

Dave — Tue, 02 Nov 2021 22:14:32 GMT

+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specific than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.
[/quote]

Well, how do you currently tell the script about the scanner's status, i.e. how is it supposed to learn that it's out of sync or not?
[/quote]

That's what I'm asking--how to make a script learn whether its out of sync or not, and, if it is, how to correct that. I don't mean to be vague--I haven't actually run the script in the scanner yet, so I don't have a good feel for the interfacing. I
[/quote]

This is impossible to answer if you cannot describe what interfacing options your scanner setup provides and how you intend to use them.

Generally
https://www.millisecond.com/support/docs/v6/html/language/attributes/pretrialsignal.htm
https://www.millisecond.com/support/docs/v6/html/language/attributes/posttrialsignal.htm

and
https://www.millisecond.com/support/docs/v6/html/language/elements/port.htm
for generic signalling from Inquisit to external devices.

Also https://www.millisecond.com/support/docs/v6/html/howto/howtocontroltiming.htm to understand the various timing components involved in a trial.

[/quote]

Thank you, it seems like /posttrialpause should work for the problem I imagined encountering per the findings from this thread https://www.millisecond.com/forums/Topic4796-3.aspx. The comp will be linked to the scanner via USB. The scanner will send a pulse every fMRI BOLD volume. The pulse is routed to the comp in the form of an apostrophe key stroke. Is this compatible somehow, ie, can /pretrialpause register an apostrophe, or is it only an integer expression?
[/quote]

This implies that the USB interface presents to the computer as a standard keyboard. /pretrialsignal can accept keyboard input. You need to specify the numerical scancode corresponding to the character the device sends. That should be 40 for ' on a US keyboard layout.

RE: fMRI timing precision

troyh — Tue, 02 Nov 2021 21:59:51 GMT

+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specific than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.
[/quote]

Well, how do you currently tell the script about the scanner's status, i.e. how is it supposed to learn that it's out of sync or not?
[/quote]

That's what I'm asking--how to make a script learn whether its out of sync or not, and, if it is, how to correct that. I don't mean to be vague--I haven't actually run the script in the scanner yet, so I don't have a good feel for the interfacing. I
[/quote]

This is impossible to answer if you cannot describe what interfacing options your scanner setup provides and how you intend to use them.

Generally
https://www.millisecond.com/support/docs/v6/html/language/attributes/pretrialsignal.htm
https://www.millisecond.com/support/docs/v6/html/language/attributes/posttrialsignal.htm

and
https://www.millisecond.com/support/docs/v6/html/language/elements/port.htm
for generic signalling from Inquisit to external devices.

Also https://www.millisecond.com/support/docs/v6/html/howto/howtocontroltiming.htm to understand the various timing components involved in a trial.

[/quote]

Thank you, it seems like /posttrialpause should work for the problem I imagined encountering per the findings from this thread https://www.millisecond.com/forums/Topic4796-3.aspx. The comp will be linked to the scanner via USB. The scanner will send a pulse every fMRI BOLD volume. The pulse is routed to the comp in the form of an apostrophe key stroke. Is this compatible somehow, ie, can /pretrialpause register an apostrophe, or is it only an integer expression?

RE: fMRI timing precision

Dave — Tue, 02 Nov 2021 21:01:53 GMT

+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specific than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.
[/quote]

Well, how do you currently tell the script about the scanner's status, i.e. how is it supposed to learn that it's out of sync or not?
[/quote]

That's what I'm asking--how to make a script learn whether its out of sync or not, and, if it is, how to correct that. I don't mean to be vague--I haven't actually run the script in the scanner yet, so I don't have a good feel for the interfacing. I
[/quote]

This is impossible to answer if you cannot describe what interfacing options your scanner setup provides and how you intend to use them.

Generally
https://www.millisecond.com/support/docs/v6/html/language/attributes/pretrialsignal.htm
https://www.millisecond.com/support/docs/v6/html/language/attributes/posttrialsignal.htm

and
https://www.millisecond.com/support/docs/v6/html/language/elements/port.htm
for generic signalling from Inquisit to external devices.

Also https://www.millisecond.com/support/docs/v6/html/howto/howtocontroltiming.htm to understand the various timing components involved in a trial.

RE: fMRI timing precision

troyh — Tue, 02 Nov 2021 20:53:54 GMT

+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specific than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.
[/quote]

Well, how do you currently tell the script about the scanner's status, i.e. how is it supposed to learn that it's out of sync or not?
[/quote]

That's what I'm asking--how to make a script learn whether its out of sync or not, and, if it is, how to correct that. I don't mean to be vague--I haven't actually run the script in the scanner yet, so I don't have a good feel for the interfacing. I

RE: fMRI timing precision

Dave — Tue, 02 Nov 2021 20:47:52 GMT

+x[quote]

[b]troyh - 11/2/2021[/b]
+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specific than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.
[/quote]

Well, how do you currently tell the script about the scanner's status, i.e. how is it supposed to learn that it's out of sync or not?

RE: fMRI timing precision

troyh — Tue, 02 Nov 2021 20:23:55 GMT

+x[quote]

[b]Dave - 11/2/2021[/b]
+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specifica than that if you want any useful input.
[/quote]

Okay, the experiment consists of trials that require a response to complete followed by intertrial pauses. After a trial, say the script and the scanner are desynchronized by 1 second. Is there a way to update the script such that the following intertrial pause will be 1 second less in duration, so that, for the next trial, the scanner and script are synchronized again.

RE: fMRI timing precision

Dave — Tue, 02 Nov 2021 20:14:34 GMT

+x[quote]

[b]troyh - 11/2/2021[/b]
Hello, I was wondering if someone could help me make sure my inquisit script is aligned to an fmri scanner throughout the experiment. I understand /pretrialpause will make the script wait for a pulse, however, is there additionally a way to correct for potential lag between trials? In my experiment, trials are not fixed, the timing depends on responses.
[/quote]

You will have to be way more specifica than that if you want any useful input.