In the first part of this series, I provided an overview of market research and how our tools are evolving. In this second installment, the focus will be on Quadrant 3 – Physiologic Techniques.

As shown in the diagram, physiological methods are all conducted with the knowledge of the test subject, and, for the most part, the focus is on the physical response (even when verbal responses are obtained). Whether for eye tracking, galvanic skin response, fMRI, or any other form of physiologic response testing, measurement equipment is involved.
People spend entire careers in this field of study. Many applications are borrowed and then modified from medical research applications. This has not been my primary professional area of focus, but it’s clearly an important field to watch and learn from as it evolves.
To use these methods, one must first know something about the basic brain structure. The brain is divided into three primary “levels”…
The brain stem is the first. It controls autonomic nervous responses, such as respiration, heart rate, perspiration, and reflexes. It keeps the body running and secure. It doesn’t think and it doesn’t feel – it responds; in humans, this response is often in response to something it is thinking or feeling (conditional reflexes, for example).
The second level to evolve was the limbic system. According to the NIH Medical Encyclopedia, “The limbic system of the brain is a group of structures which govern emotions and behavior [and]… is involved in the formation of long-term memory, and is closely associated with the olfactory structures.” There’s much debate as to whether the limbic system really is a distinct secondary level, but I bring it up here because the brain has many components, not all measured equally well by various methodologies.
The third level, of course, is the cerebral cortex. When we describe “left brain” (rational / logical / language) vs. “right brain” (emotional / artistic) activity, we’re most often talking about the cortex.
The Vest
I’ve always been a bit skeptical of marketing research methods that focus on measuring autonomic nervous responses because it’s often unclear what a participant is responding to. At a professional training event a few months back, Innerscope Research talked with us about its monitoring vest. A very impressive advancement in biometric monitoring as individuals no longer need to be “hooked up” to a machine with sticky electrodes or other sensors; all are embedded in the vest.
Let’s assume that a biometric company such as Innerscope really can tell the difference between a positive and negative emotion based on length of response time (which is what I remember being told) and that there is a way to quantify the differences between similar emotions, such as fear and anxiety or anger and frustration. And let’s further assume that reactions can be measured in milliseconds and don’t take multiple seconds to register – so that we can accurately correlate emotion to stimuli. Granted, that’s a lot of assumptions and I’m not sure I’m completely on board with this. But let’s assume we’re there. If we used this in ad testing or in shop-alongs or another method, we’d still be left wondering “why” someone had the reaction(s) they did – which requires us, as marketing researchers, to hybridize these approaches to include verbal probing.
For those who argue that people have trouble articulating their emotions, I’d argue that’s more often true with emotions on the extreme ends of the spectrum: love, happiness, depression. If we’re good at our jobs, we can probe our way to understanding most other reactions
EEGs
An EEG, or electroencephalography, studies brainwave activity along the scalp – virtually in real-time. Over the years, the electrode configuration of the “caps” used have become more complex (as shown in the picture), but it still remains quite true that the EEG can’t measure deep limbic system functions. Having said this, there are some great applications, when used in conjunction with other techniques, such as copy testing. (See Quirks for an example.)
fMRI
Functional MRI (magnetic resonance imaging) is at its earliest stages of being used by marketing researchers. In this quadrant, this method falls in the extreme lower / right corner. There’s no getting around the fact that you’re taking a test when you’re asked to take off all your metal (eyeglasses, jewelry, etc.) and go into a tube for 15 minutes to an hour. (While in the tube, the participant’s brain blood-flow is being monitored in response to what they’re seeing / hearing / smelling / etc.)
For general marketing research purposes, this (currently) seems too extreme and invasive to me. I appreciate the fact that fMRI can measure the whole brain, and just not certain parts. And I look forward to how marketing research applications will evolve into in the future. I hope my ethical and liability concerns can be addressed, but I’m not sure.
Eye Tracking
Of all the physiological research methods, the one I’m the most familiar with is eye tracking. Some might argue that it’s the least invasive and that it allows the participant to understand why the researcher is using this tool. Early applications in market research were in assessing outdoor advertising or print ads in magazines. The experiences were simulated (e.g., driving on a highway, flipping pages of a mocked-up magazine) and its application was almost always done as an adjunct to other ad-testing measures.
Advances today are pretty impressive. Doing a usability test? The eye-tracking cameras are built into some monitors so the user has no “extra presence” or unusual equipment in the room. In fact, the interviewer can be out of the room, watch the usability exercise, and use the video from the test as a discussion springboard.
Another application I like is having participants shop wearing a special pair of eye tracking glasses. In a real store, not a simulation, we can see their entire shopping experience; again, we can use the video to follow-up with them in a post-shop interview.
Closing
There are other methods to be sure. My hope was to provide a flavor of what’s currently going on in this quadrant. Further, the point must be made that research in this quadrant, in my view, needs to be contextualized; I wouldn’t conduct any of these methods alone without some means of probing potentially less-than-clear reactions.
What would you add to this discussion?

Interesting article – thank you! It’s funny as on the one hand it seems early days in this field and yet the medical techniques have been around for quite some years.
The physiological research we’ve been working on (such as GSR and EEG) has been using “kit” that works in the home (hooked up to an online panel and using panellists about whom we know quite a lot already). We’ve not used more impressive but somewhat oppressive fMRI techniques for the reasons you describe.
The results are interesting but do often require probing or survey based responses as well to try to shed more light on them. Sometimes these new physiological techniques are marketed as “mind reading” but they really cannot achieve that yet and so they add to the tool kit but do not yet replace or displace interviews (quant or qual).
One area where the physiological responses ARE becoming more useful though is in calibration…for example one can get respondents to react to 10 known successful examples of a thing (ad, concept, package etc), 10 known failures and then when one pops the new stimulus into the mix you can at least see where the physiological data stream comes out compared to a comparison set of “angels and demons”. It’s a start.
Bit of a pain selling it to clients though as it’s hard to be entirely confident about the benefits but I can confidently guarantee it will cost more!
One other technique
Love the last bit on cost! The “calibration” application you describe I like. Ever tried this with animatics or prototypes (rough) packaging?