ERPLAB Toolbox Manual

Version 3.0

10 October 2012

User's Manual written by Candace Markley, Steve Luck, and Javier Lopez-Calderon

ERPLAB Toolbox core designed by Javier Lopez-Calderon and Steve Luck

Important note: Because this is not commercial software, bugs are inevitable. In some cases, errors will occur leading to a message that instructs you to report the error to the EEGLAB developers. If this happens, please report the error to us at erplab@erpinfo.org and not to the EEGLAB developers.

The purpose of this User's Manual is to provide a detailed description of the ERPLAB functions, along with a discussion of the overall design of the toolbox. For "how-to" information, see the ERPLAB Tutorial, which provides step-by-step instructions for analyzing a typical set of data. A Frequently Asked Questions document is also available.

We have set up three web-based discussion groups. One is designed for people to ask questions and give and receive advice about how to use ERPLAB Toolbox. Another is designed for reporting bugs and describing work-arounds. The third is designed to give users the opportunity to make suggestions about modifications and new features. They can be accessed at http://erpinfo.org/erplab/erplab-discussion/erplab-discussion-forum/ (you will need to join the erpinfo.org web site to access these discussion groups). There is also an email list, erplab@erpinfo.org, that you can use to send questions and announcements to the community of ERPLAB users. If you would like to join this list, you should go to http://mail01.cmb.ucdavis.edu/mailman/listinfo/erplab. To communicate privately with the developers, send an email to erplabtoolbox@gmail.com.

Please keep in mind that this is FREE software, and we do not have the resources to provide the level of support that commercial software vendors can provide.

ERPLAB Toolbox is a freely available, open source set of MATLAB routines for analyzing event-related potential (ERP) data. It uses the freely available, open source EEGLAB toolbox as a front end. That is, EEGLAB is used to read in EEG data files and perform various operations on the EEG, and ERPLAB contains a set of new functions, which are added as plug-ins into EEGLAB, extending the set of operations that a user can perform within EEGLAB. These plug-ins include additional EEG processing manipulations (e.g., new functions for marking trials with artifacts) along with functions that provide powerful methods for sorting EEG epochs and averaging them together. Once a set of averages has been created, they are saved in binary files and can be exported into text files (allowing them to be imported into other ERP analysis systems).

ERPLAB also contains a set of routines that operate on the averaged ERP waveforms (e.g., making difference waves, plotting, filtering, measurement, etc.).

As in EEGLAB, the ERPLAB routines can be accessed from the Matlab command window and from Matlab scripts in addition to being accessed from the EEGLAB GUI. Consequently, ERPLAB provides the ease of learning of a GUI-based system but also provides the power and flexibility of a scripted system.

The ERPLAB routines were inspired by ERPSS (the Event-Related Potential Software System), which was developed in Steve Hillyard's lab at UCSD under the direction of Jon Hansen. However, the code is entirely new, and it is not designed to be fully backward compatible with ERPSS. Anyone who knows how to use ERPSS will be able to learn ERPLAB rapidly. But those who do not know ERPSS will also find ERPLAB approachable because of the GUI.

ERPLAB also relies heavily on EEGLAB as a model for its GUI and its conventions.

Table of Contents

INSTALLATION INFORMATION

LEARNING TO USE ERPLAB TOOLBOX

BASIC ERPLAB PROCESSING STEPS

IMPORTANT BACKGROUND CONCEPTS AND DATA STRUCTURES

USING EEGLAB

THE EVENTLIST STRUCTURE

CREATING AN EVENTLIST

EXPORTING, EDITING, AND IMPORTING EVENTLISTS

Boundary Events and Disabled Events

ASSIGNING EVENTS TO BINS WITH BINLISTER