Background
This guide serves as a specific set of instructions to talk you through analysing data from Jones & Ward (2019). As you know the experiment explores the differences in the ability to recognise objects when they’ve been encoded under two different conditions. Specifically, items to be remembered were either presented rhythmically or arrhythmically. The data we will examine in this tutorial was recorded at the recognition phase – so there is no perceptual difference between the items we are comparing, the only difference between them is that when the items were presented to be remembered they were presented rhythmically or arrhythmically. We will use a well-established technique that will allow us to generate an Event Related Potential (ERP). This will allow us to examine the electrophysiological response generated by the brain during the presentation of stimuli that were encoded under two different conditions.
Analysis
This tutorial will take you through the analysis procedure for data from one participant and how to generate a ‘grand average’ – across multiple participants. You can apply the techniques you learn here to analyse the dataset that has been made available to you for portfolio. We implement the analysis in a software called EEGLAB. The primary benefit of using EEGLAB is that it is, for the most part free and extremely well supported by the online community. Whilst the initial distribution of EEGLAB required a programme called Matlab to run – EEGLAB can now be downloaded as a ‘compiled’ version. Whilst the compiled version doesn’t have all the same functions as the full Matlab version – it is easy to get up and running and operates via a Graphic User Interface (GUI), so you won’t need to code.
If you would prefer to install Matlab and use the EEGLAB that is attached to it you are welcome to do so, but we will be providing instruction and support on the stand alone compiled version of EEGLAB.
Teaching and Learning
As in all the software skills we hope you will develop in this programme, we hope that learning how to use EEGLAB is in itself a good skill to have. However, our primary goal is for you to become familiar with the analysis process of EEG, understand how data is cleaned, and manipulated in experimental settings. The idea is that you get a greater insight into the methods used in analysing EEG and how this effects the conclusions we draw about how the brain, and how cognition, works.
You can run through this guide on your own but there will be dedicated in class sessions where you will be able to go through the analysis and get in-person support and feedback from module staff.
Where to Get Help?
- You will be given time in class to explore EEGLAB - speak to tutors and get in person support.
- Use the Resources section for online help.
- Book an online or in-person one-to-one session with module leaders.