Setting up an MEG and EEG experiment

Sheraz KHAN

Research Fellow

Athinoula A. Martinos Center for Biomedical Imaging

MGH/MIT/Harvard

Overview

Experimental Paradigms for MEG/EEG

Testing Experimental Paradigms

A typical MEG/EEG Visit

12/24/2015 Setting up an MEG and EEG Experiment 2/40

-Inexpensive

-Portable

-Clinical

12/24/2015 Setting up an MEG and EEG Experiment

Electricalencephalography (EEG)

Not distorted by skull and scalp/ Simple modeling

Less preparation time/ Reference free

Best Results combing MEG with EEG (Wood et al,Science,85)

Khan & Cohen, 2013

Magnetoencephalography (MEG)

Upright Supine

The high temporal resolution of MEG/EEG not only allow

us to follow sensory/cognitive events at millisecond

resolution but also decipher feedforward from feedback

High temporal resolution

block vs event related design

Block design Event related design

The most common experimental

design is the interleaved

presentation of stimuli of various

categories and valences

Clinical Applications

Dipole Localization

MEG Sensor SpaceEEG Sensor Space

Sleep studies

Brain Rhythms

During sleep

Sleep Cycle

Four basic stimulation systems

Auditory

Visual

Somatosensory

Olfactory

Auditory Visual

OlfactoryTactile-Somatosensory

Electrical-Somatosensory

Auditory Experiment

Cortical ResponsesTransfer function

Protocol

Visual Experiments

Khan et al, PNAS ,201312/24/2015 Setting up an MEG and EEG Experiment

Protocol

Electrical Mechanical

Tactile Khan et al, Frontiers Human Neuroscience ,2014

Somatosensory Experiments

Frequency-Tagging: When stimulus with specific

temporal encoding (e.g., visual pattern flickering at a well-

defined frequency) may trigger brain responses locked to

the stimulus presentation rate and its harmonics.

Khan et al, Brain ,2015

Visual Tagging

Somatosensory Tagging Khan et al, Brain ,2015

Baldauf et al, Science ,2014

Overview

Adjusting Stimulus Parameters

Stimulus Duration

Inter-Stimulus interval (ISI)

Inter-Stimulus Jitter (ISJ)

Stimulus Onset Asynchrony (SOA)

Stimulus Duration

Single Trial

Stimulus programming options

Open Source

Matlab based Psychophysics(psychtoolbox.org)

Python based PsychoPy (psychopy.org)

Commercial Packages

Presentation (neurobs.com)

Stim2 (compumedicsneuroscan.com)

Testing Timing, Jitter, Sound level, Brightness

Photo Diode

Jitter

Protocol

Sound Meter

Timing Accuracy

Averaging evoked fields

Number of Trials

Testing Stimulus equipment for Artifact

Auditory

Tactile

Reponses Pad

Adjusting Hardware Setting

Sampling Rate

Filter Bandwidth

Auditory Brainstem Responses

Working Memory

Behavioral Testing

Somatosensory priming

Valence Testing

Population Diversity

Overview

A typical visit starts the day before, with a Call or email to

the subject to remind:

Sleep Well

Not to drink to much coffee or energy drink

No Makeup

Weight and if applicable eyeglasses prescription

Appropriate clothing

Preparing EEG cap,

Extra electrodes

HPI and digitizer

Stimulus testing , Auditory gains, brightness, room light.

Digitizer Head Position Indicator coilsEEG Cap

ElectrodesTrigger Box

Before the Subject arrives

Tuning Channels

Acquire Empty room

Noise Co-variance matrix Acquisition software

Prepare bedding

Prepare gowns

IRB/Consent forms

Bedding

MEG/MRI compatible

Glasses

Scrubs

After the Subject arrives

Consent forms

Explanation of protocols

Change to gown

Test Subject for Artifact

Screening form

Two Types of artifacts:

Biological

Blinks/secedes

Cardiac

Non Biological

Dental

Metal on body (internal/external)

Jewelry

Brain Stimulators

Degaussers

Different artifacts

Head digitization

Position coils

Polhemus Data

Head digitization

Electrode Placement

Once you have placed the

subject in the MSR close the

MSR door

Use intercom; ask the subject

to relax

Check MEG signals

Once you start the acquisition

and at the beginning of each

run, you will be prompted to

record HPI

Once HPI measurement is ok,

you can start recording.

Continuously inspect the

quality of your data!

If individual bad channel

appears during the recording,

mark it as bad channel12/24/2015 Setting up an MEG and EEG Experiment

Intercom

During Experiment

After Experiment Finishes

Tell subject you are opening the door

Remove HPIs and electrodes/EEG cap

Subject coming out

After the Subject leaves

Clean and disinfect the

electrodes/EEG Cap and the HPI

Clean the MEG helmet and chair.

Switch off the video projector

Switch off the light in the MSR

Log out of the acquisition computer

Take with you any leftover of your

presence (used papers,belts….)

Wash Electrodes

Clean Countertops

Thank you

Thank You

Conflict of Interest Disclosure

Sheraz Khan

Advanced Imaging in Clinical/Translational Neuroscience

Research

April 13-15, 2015

I have no relevant financial

relationships with a commercial entity

producing healthcare-related products

and/or services.

Setting up an MEG and EEG experiment

Documents

Fast Multipole Acceleration of the MEG/EEG Boundary Element …cmp.felk.cvut.cz › ftp › articles › kybic › fmm_article_2.pdf · 2005-06-22 · encephalography (MEG/EEG). The

Introduction to ElectroEncephaloGraphy (EEG) and ... · Introduction to ElectroEncephaloGraphy (EEG) and MagnetoEncephaloGraphy (MEG). Outline zOrigin of EEG and MEG signals zEEG

The MEG Experiment T. Mori for the MEG Collaboration

Preprocessing for EEG & MEG Tom Schofield & Ed Roberts

Generative Models of M/EEG: Group inversion and MEG+EEG+fMRI multimodal integration Rik Henson

MEG Experiment - PSI

Bayesian inference in EEG/MEG©rémies_Mattout... · Bayesian inference in EEG/MEG Workshop on Bayesian approaches in neuroscience –Karolinska Institute –2nd of Frebruary 2016

What are we measuring in EEG and MEG?

An Introduction to Beamforming in MEG and EEG · Stephanie Sillekens – Beamforming in EEG/MEG An Introduction to Beamforming in MEG and EEG Stephanie Sillekens Skiseminar Kleinwalsertal

Dynamic Causal Modelling for EEG/MEG: principles · Dynamic Causal Modelling for EEG/MEG: principles Adapted from the DCM course slides of J. Daunizeau

EEG versus MEG localization accuracy: Theory and experiment

EEG / MEG: Experimental Design & Preprocessing Lena Kästner Thomas Ditye

Neurophysiological basis of MEG/EEG

Unsupervised machine learning for analysis of EEG and MEG ... · Introduction Issues in ICA of EEG/MEG Testing independent components Causal analysis Discussion Unsupervised machine

EEG/MEG source reconstruction of electric wrist/Braille

Localizing Bicoherence from EEG and MEG - HHIiphome.hhi.de/samek/pdf/AvaNIMG18.pdf · 1 Localizing Bicoherence from EEG and MEG Forooz Shahbazi Avarvand 1, Sarah Bartz2, Christina

MEG and EEG analysis using - Biomedical Imaging Group"

Physiological Basis of EEG/MEG Signals, Forward …wpenny/talks/msc-meeg-sources.pdf · Physiological Basis of EEG/MEG Signals, Forward Models and Source Reconstruction Physiological

MfD EEG/MEG Source Localization 4 th Feb 2009

Functional neuroimaging - NYU Psychology · MEG MEG EEG Main advantage over EEG: better spatial resolution (millimeters for cortex, worse for deeper sources) Magnetic fields pass