Biometrics Applications in Research

March 31, 2024

Marketing researchers employ biometrics to measure physical responses to different stimuli such as online, television or print advertising, a product, or a service.  Biometrics is a very broad category of measures that includes functional magnetic resonance imaging (fMRI, measuring blood oxygen levels), electroencephalography (EEG measuring "brain waves," brain electrical activity recorded on the scalp), galvanic skin response (GSR), eye movement tracking, iris or retina recognition, facial recognition, fingerprint matching, gait recognition, geometry of the hand, ear and fingers and voice recognition.  Some biometric measures are useful in marketing research, and some are not.

Biometrics is viewed as part of the new science of neuromarketing.  The advantage of biometric measures is that they are accurate in measuring physical responses to stimuli even if people are not conscious of those responses. Several biometric applications augment traditional marketing research methods and measure responses such as cognitive workload, memory, attention, stress and sensory responses; however, these methods are not necessarily useful in measuring emotional responses.

Some of the more popular biometric measures are explored here as well as considerations for use of biometrics in marketing research.

Eye Tracking

Eye tracking measures attention by allowing researchers to monitor where participants’ eyes travel as they view online, television or print advertisements, websites, or any other kind of media. Without relying on a verbal response, marketing researchers can determine which elements are noticed and which ones are most focused on.

Eye movement tracking provides a useful indication of attention.  On the other hand, the technique is probably not useful for understanding or predicting consumer recall and behavior.

Facial Coding

Facial Action Coding System (FACS) is a system of human facial expressions that have been categorized allowing practitioners to decode the underlying emotion that registers on the human face in response to stimuli, no matter how brief the exposure. Effective use of facial coding allows researchers to gauge the emotional reactions of consumers toward an advertisement, product or service.  While the concept of facial coding may have good potential in marketing research, some describe the approach as highly subjective and unreliable.  

Galvanic Skin Response (GSR)

Galvanic skin response (GSR) refers to the measurement of electrical conductance of someone’s skin. GSR detects emotional reactions to stimuli. Sometimes researchers find it best to combine eye tracking with GSR so they can get a sense for intensity of emotional responses as well as precise identification of the elements that coincided with emotional responses.

Heart Rate Monitoring

Heart rate can be measured with an electrocardiograph (ECG) machine and used by marketing researchers to understand physiological responses to stimuli. Like other biometric measures, the idea is that these physiological responses are thought to underlie emotions that may or may not be noticeable to people at a conscious level.

Other Types of Biometrics

Other examples of biometric technologies used in marketing research include functional magnetic resonance imaging (fMRI) which measures brain activity via blood flow, facial electromyography which monitors facial movement and muscle activity in the eyes, electroencephalogram (EEG) which measures brain electrical activity. (For more information on the use of fMRI and EEG in marketing research, see the Q2 Insights blog “Neuroscience Applications for Marketing Research.”)  

Considerations for Employing Biometrics in Marketing Research

People process their social environment in much the same way. Information flow, from perception to the storage and use of information, involves four processes:

  • Attention (how we gather and select information)
  • Interpretation (how we give incoming information meaning)
  • Judgment (how we form impressions and make decisions about incoming information)
  • Memory (the storage of that information for later use)

These four stages can occur along a continuum from automatic, unconscious processing to controlled, conscious processing. At every stage there is more or less emotion that coincides with the information being processed. Furthermore, every rational or emotional reaction has underlying physiological correlates. In other words, if we are stressed or excited or scared or simply working hard at math problems, there are always physiological responses that go along with our emotions and thoughts. The degree to which measures like heart rate, skin response, eye tracking, facial coding and other types of biometrics provide insight into consumer behavior should be judged on a case-by-case basis.

Some biometrics may have clear advantages over others, but most do not provide the whole picture by themselves. For example, eye tracking may be particularly useful for understanding which elements of media are most noticeable, but eye tracking alone will not spell out the thoughts and feelings that accompany the eye movements. Likewise, there are many different emotions that go along with increased heart rate. The interpretation of measures such as heart rates or galvanic skin responses can be subjective, and the extent to which these measures can predict recall or purchasing behavior is questionable.

All emotions involve behavioral, nervous system and hormonal responses. While biometric measures can provide a window into responses that lie below level of awareness, it is still incumbent upon researchers to use their traditional interviewing skills to increase overall understanding of consumer behavior.

Biometrics Augments Traditional Marketing Research Methods

The use of biometrics allows marketing researchers to couple traditional research methods, such as interviewing people about what they are thinking and feeling, with measures that do not depend on verbal articulation. Furthermore, the use of biometrics allows researchers to tap into the minds of consumers as they mentally process and subconsciously respond to messaging and overall branding.

While biometrics offers the advantage of capturing unconscious or subconscious reactions to marketing media, the benefits of employing biometric measures in marketing research must always be weighed against practical issues such as access to equipment, access to expertise, degree of invasiveness to research participants and overall costs.  

Q2 Insights, Inc., is a research and innovation consulting firm located in San Diego.  

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