Response based analysis

Dear Team,

Thank you very much for such wonderful toolbox for analysis. I am new to brainstorm toolbox and was wondering whether it is poosible to extract the trails based on the response from the participant.

For example, Trigger 10 for condition1, Trigger2 for condition2. In response to condition 1 and condition 2, the participant does respond with values 1 and 2. I want to extract trials/epochs corresponding to correct trials and incorrect trials separately for both the conditions.

Thanks,
PG

Hello
You can probably use the process “Events > Combine stim/response”.
Let me know if the instructions in the process are not clear enough, or if it doesn’t do what you need.
Francois

I am giving Trigger 10 for condition 1 and Trigger 20 for condition 2 and responses are 1 and 2 respectively.
10_101, ignore , 10 , 1
20_202, ignore , 20 , 2

Can you please correct me if I missed anything. how to get the Maximum delay between grouped events value ?

Thanks,
PG

There is nothing to compute easily latencies between events in Brainstorm.
You could probably with a few Matlab command lines, computing the different for the field “times” of the events generated by the process (if you create 2 output events, eg. 10_101 and 1_101).

You can get the events structure in .mat file corresponding to the “Link to raw file”:
https://neuroimage.usc.edu/brainstorm/Tutorials/EventMarkers#On_the_hard_drive

Thank you very much. I didn’t see any change in the number of trials. the no of trials are same, If there are some incorrect response, it should change the number of trials for both conditions.

Can you please suggest some example so I becomes more clear.

This process is not supposed to be used on imported trials.
You should run in on your continuous recordings, to create new categories of events that include only one subtype of events (eg. “event A followed by event B” and “event B preceeded by event A”)
And then import only these new events in your database.

Hi Francois,

Thank you very much for your response. I will implement this suggestion and update you. Also, it is possible to do the co-registration MEG with CT-scan instead of MRI images.

Thanks,
PG

You cannot get the cortex surface from a CT scan, therefore there is no use for it as this stage.