Frequently Asked Questions
Feel free to add comments (but please suggest new FAQs by sending an email to erplabtoolbox@gmail.com).
Installation
I’ve just installed the latest release of ERPLAB, and only some of the functions work. Other functions do not seem to work at all. What is going on?
The Matlab path may not include the new ERPLAB functions. You must update the Matlab path by selecting File > Set Path from the Matlab command window. Delete any old EEGLAB and ERPLAB folders from the path, and re-adding the EEGLAB folder (and all subfolders) to the path by clicking on Add with subfolders and selecting the path to the EEGLAB folder (which contains the ERPLAB folders). If you still have problems, you may want to clear all of the path information by clicking Default prior to clicking Add with subfolders.
I’ve just installed the latest release of EEGLAB, and I get warning messages anytime I try to do anything in EEGLAB or ERPLAB. What is going on?
The Matlab path may include a set of routines that are used to take the place of the Matlab Signal Processing Toolbox. To avoid this problem, update the Matlab path by selecting File > Set Path from the Matlab command window. Delete any paths with external/fieldtrip in them and save.
Plotting
I would like to create a single plot that overlays the waveforms from different files. How do I do this?
In the current version of ERPLAB, it is not possible to directly plot waveforms from different ERPsets in the same plot. To accomplish this, you can append one ERPset onto the end of another ERPset with ERPLAB > Append ERPsets. This will create a new ERPset that has twice as many bins (all the bins from the first ERPset followed by all the bins from the second ERPset). You can then overlay the bins corresponding to the original first and second ERPsets. (We will create an easier method for this in a future version of ERPLAB.)
EventList
I have already epoched my data in EEGLAB. Is it possible to add an EventList to a dataset that was epoched using EEGLAB?
No. To use most ERPLAB functions, you must create the EventList in the continuous data and use ERPLAB's "bin epoching" function to epoch your data. ERPLAB creates links between the EventList and the event information in the continuous data, and many ERPLAB functions would "break" if we tried to create an EventList on an epoched dataset. You are free to write your own scripts to do this, and it might work for a specific experiment, but there is a good chance that this will lead to problems at some point. Note that some ERPLAB functions do not make use of the EventList (EEG Channel Operations, and Filter & Frequency Tools), and these functions can be applied to data that were epoched with EEGLAB.
