Epoching Clinical Data


If you get the error: “can only open 132 chans” run HeadEdit.exe on .edf file.

1.Copy HeadEdit.exe file into folder with data.

  1. Run in Command Prompt
  1. Open edf format in Neuroscan
  1. Mark triggers:

Transforms>Voltage Threshold

Operation: Add events

Direction: Greater than

Threshold: 100000 (check baseline and trigger max value)

Refractory Period: 200

Channel: DC1

Stim Code: 1

Repeat for Channel: DC2 and Stim Code:2, etc.

You will see numbers on marking the trials below the trigger channels

  1. Save as .cnt format
  1. Create .ev2 file:

Transforms>Event file

check: Stimulus

check: Report offset in seconds

select output file name (same as .cnt name)

  1. Create .eeg file (epoch data):

Transforms>Epoch file

check: Event file > select ev2 file you just created

check: Event file offsets are in seconds

X Minimum: -500

X Maximum: 1000

select output file name (same as .cnt name, but add _epoch)