S-114.3760 Practical 1
EEG experiment: Mismatch negativity (MMN)
In the first practical we will redo a basic EEG experiment with one subject to test whether we can detect the mismatch negativity (MMN; a component of the auditory event related potential (ERP)). The MMN is evoked by an infrequently presented stimulus ("deviant") differing from the frequently occurring stimulus ("standard") in one or several physical parameters. Our deviants will differ in frequency.
What you need to do / What you will do
For the first practical the experimental setup is ready. Your task is to learn to measure the EEG, analyse the data and write a scientific report. You will be given instructions on how to do it.
1. Before you come to the EEG measurement
I. Read two short texts (passwords were given in the email):
1. CBRU MMN introduction: a short 1.5 page long introduction to MMN to understand what you are going to measure, if you didn't know before.
II. Based on the article's methods section you just read write down on a piece of paper what you want to find out about the experiment we are doing, to be able to write your own scientific article's methods in a similar manner. I will provide you with the details you want (i.e. have written down) at the measurement.
2. Tervaniemi et. al. (1999): one (of the several thousand) mismatch negativity articles. Read sections 2.1.1-2.1.4. (part of methods; 1 page). Pay attention to what kind of things they have reported (subjects age, what electrodes, frequency of standard stimuli, etc.).
III. The subject will be reading a book while doing the experiment. Bring a book with you. We only have muumipeikko in our lab.
2. EEG experiment
The experiment is done in our lab on the 4th floor of the magnethouse Otakaari 5I. If your experiment is at 4 pm make sure you have Laura's phone number to get in as the doors are closed.
BE ON TIME! If your exercise starts at 16 it will start at 16:00.
What is done during the experiment
1. Lab tour
2. One of you in each group will act as a subject (the task is very simple, the subject just has to read a book and listen to beeps). If you are interested in being a subjet, bring a towel so that you can wash the electrode gel out of your hair. The gel itself is in no way harmful and you can also wash it away at home (I've taken the bus several times with gel in my hair). The others will prepare the EEG cap and use the software.
3. The introduction takes about 30 min, the preparing about 30 min, and the experiment itself about 1h.
3. EEG data analysis
Instructions on how to do the analysis:
Scripts for running all files:( ERP_all_files.m &
come to the practical read through the Sams et al. (1985) paper ( .pdf)
Because we do not have the time to measure several subjects during the practicals I will provide you with a CD of the data your group and the data the other groups have gathered. In this way your number of subjects will be four instead of one. You will be given written instructions on how to get your data into matlab and how to analyse it.
4. Scientific article
You have now repeated a basic EEG experiment and want to report it in some scientific journal. How do you convince the editor that your paper is worth publishing?
Instructions on how to write your article:
The schedule for writing the paper is unfortunately very tight so that you get feedback of your report
before writing the next. Do your best. Reserve
at least 4-8h time for the writing process. Laura (for TKK) and Christina (for Helsinki) will give feedback on each
and every paper so that you can improve your writing skills for the second paper. The paper itself and how you have
presented your results will be graded and not how you do the measurements or analyse the data. Thus, each and
every student hands in an own paper.
Deadline: 30.11 by 15:45. TKK: magnethouse, the blue post box on the 4.
floor; HY: to Christina Krause: Siltavuorenpenger 20 C, 5. floor.
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