Eyetracking, GSR and EEG: which new research methods get you closer? PART 2: EEG & GSR


Keeping up with technology is an important job for a research agency. We get excited by any tools and techniques emerge that can help us in our mission – to get closer to consumers. However, an important consideration is to evaluate which are fads and which are keepers, embracing what is useful only.


Clients often ask us how technology can help them, so here’s a quick bluffers guide for three methods you may not have used before – what they are, how they can be used and where we think they add value.

EEG_GSR_eyetracking technology being fitted in the lab

PART 2: EEG (Electroencephalography)

What is it?

A neuroscientific tool: a way of measuring electrical conductivity on the scalp. Respondents wear a cap with sensors which take readings from sites associated with cognitive functions like emotional intensity, frustration and long term memory encoding.

What have Brass used it for?

We have used it on several occasions to investigate unconscious reactions to media.

What are the practicalities?

There is significant skill required to set up, run and analyse the findings from an EEG study, so developing a relationship with an experienced partner is crucial.

Readings are sensitive with little lag time, meaning live feeds showing the responses (e.g. frustration) are available in real time. That said, in our view it is better to await detailed analysis. Selective recall of a single respondent’s reactions can be an issue!

Whilst equipment lead times and hire costs are not prohibitive, we would recommend EEG research be undertaken in a lab for ease of data collection and to reduce potential ‘noise’ that may affect the experiment.  Whilst the cap is easy to calibrate, it can take a few minutes to get readings correct before the research session starts. Recruitment needs to be carefully planned with appropriate disclaimers arranged.

Does it get you closer to the truth?

Yes. A direct measure of a respondent’s unconscious reactions to stimulus.

As the two system model of cognition has shown us, our behaviour is often impacted by factors we are unaware of. Instinctive responses, particularly those relating to emotions, affect how we react and what we do.  EEG readings taken from the scalp correlate to relevant cognitive processes like emotional intensity, giving researchers a route to understanding what is truly driving a response to stimulus.

This can be particularly useful to compare true reactions with stated attitudes. Overlaid with other methods (e.g. traditional qual & quant methods, eyetracking), it can help you narrow down your options – which version of a communication or web page to launch.

As well as this, certain measures (like long term memory encoding) have been shown to correlate with how well television advertising performs and future consumer choice. In a pre-testing environment, being able to identify a version of your ad which scores more highly on this measure could be hugely valuable – giving you a much higher return on your media spend.

Why should I bother?

Potential payoffs often make the investment more than worth the effort. Used in combination with eyetracking (easy to do) a day or two of EEG can provide useful diagnostic information for creative development or web design.

The Brass verdict?

EEG can only become more useful as academics increase our understanding such neural correlates of behaviour, and develop models with predictive validity. One to watch.

GSR (Galvanic Skin Response)

What is it?

A biometric tool that measures tiny fluctuations in your body temperature and perspiration. Based on the same technology as the fabled polygraph test of American cop dramas, respondents wear a wifi enabled bracelet which takes readings from your wrist.

What have Brass used it for?

We have used it to investigate unconscious reactions to media.

What are the practicalities?

GSR measurements are sensitive to movement, for example if a respondent was to pick up an item from the floor, this might cause an increase in response. This means experimental designs have to be very tightly controlled or be subject to challenge. Lab environments are vital.

Does it get you closer to the truth?

We’re unsure. Readings are quite slow, and have a 1-3 second lag. When compared to eyetracking and EEG, GSR offered limited additional insight on a recent project.

Why should I bother?

It is easy to use in combination with other methodologies if you have a laboratory booked using other methods like eyetracking / EEG. 

The Brass verdict?

We remain to be convinced of its value as a methodology.

About Simon Shaw

I'm a Director at an insight consultancy. I'm interested in marketing, market research & consumer psychology. The views expressed are not necessarily those of my employer.
This entry was posted in Consumer Psychology, Methods, Qualitative research, Technology and tagged , , , . Bookmark the permalink.

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