Nicola Watts
Tech / Innovation
Understanding Emotions Using Biometrics

Fundamentally, we’re emotional creatures who occasionally act rationally. Our subconscious controls about 90% of our thoughts and feelings. The problem is that it’s not great on sharing with our conscious mind, which is why we’re not able to easily articulate our feelings.

Emotions are physical and instinctive, and are ingrained in our genes which is why they are similar, give or take, for all humans. They are activated by the release of dopamine and oxytocin in the brain, and create a biochemical and electrical reaction in our body that alters our physical state. Feelings, on the other hand, are initiated by emotions and are all in our conscious mind! They are influenced by our own personal experiences, biases and beliefs connected to a particular emotion. But not all emotions are translated into conscious feelings.

Feelings as they occur consciously can be measured using traditional direct question and answer approaches, to a point. Self-reported emotional responses are infamously inaccurate and biased! Biometric technologies can be used to measure our emotions by tapping into our unconscious responses. Every rational or emotional reaction we have involves some form of physiological response, be it behavioural, nervous system or hormonal. Put simply, our bodies react before our conscious mind has even registered what’s going on!

Most of us are somewhat familiar with biometric technologies utilised for authentication and identification purposes such as using fingerprints to unlock a smartphone, facial recognition and iris scanning at passport control, or voice recognition to access your bank account or unlock your car. You may even own a smartwatch or fitness devices that monitors your health.

Biometrics are big business, with estimates of its size at around $10.5 billion in 2015 and growing with estimates varying between $32.73 billion in 2022 or $59.31 billion in 2025. For financial transactions it’s the preferred method! But, this shouldn’t be a surprise as biometric authentication and identification systems offer higher security, convenience, accountability, accuracy and a high return on investment.

The basic premise is that everyone is unique and can be identified by their individual physical or behavioural traits. But how familiar are you with it as a market research tool to unlock our physiological responses to stimuli or events as they occur?


Why is understanding our customers’ inherent emotions important? The old adage “they may forget what you said – but they will never forget how you made them feel” stands true today for both brands and companies as it does people. Getting your customer to feel a deep positive emotion about your brand will translate into sales. If they can remember that feeling either consciously or subconsciously at the point of purchase, then they will be more likely to choose you over a competitor.

Biometric research by Nielsen published last year measured respondent’s brain activity using electroencephalogram (EEG) technology while they viewed 100 ads from 25 FMCG brands. They then combined this data with sales data and used market mix modelling to provide a measure of each ad’s contribution to sales volume. They found that ads that generated an above-average EEG score were associated with a 23% uplift in sales volume over what an average ad would generate, and that below-average ads saw a 16% decline in sales volume.

How does it work? Every time we look at a stimulus such as an advert our body subconsciously responds, whether our eyes focus on specific areas or our facial expression changes or our heart starts beating faster. Biometric research then uses sensors that are designed to specifically measure and record these different signals.

The most widely used biometric measurement technologies fall into five basic camps: eyes, face, skin and muscle, heart rate and respiration and brain activity.

1. Eye Movement

Eye tracking monitors both corneal reflection and pupil dilation (pupillometry) through an infrared camera pointed towards the eyes. It can pinpoint what someone is looking at either on a screen, store shelf or elsewhere, what draws their attention, their gaze pattern, the order they look and for how long. Pupil dilation reflects emotional arousal, both positive and negative, with no delineation – the larger the dilation the stronger the arousal. It provides data on visual attention, engagement, emotional arousal and fatigue.

2. Facial Coding

Facial expression analysis measures the activity of the facial muscles through a camera pointed towards the face and relates these to an emotional response either via a trained Facial Action Coding System (FACS, a catalogue of 5,000 muscle movements) coder or specialised computer software that automates the analysis. It’s a diagnostic tool to understand whether a piece of stimulus has elicited a specific facial expression which in turn is linked to a specific emotion. It provides data on emotional

3. Skin and Muscle activity

This covers two main technologies: Galvanic skin response (GSR) and Facial Electromyogram (EMG).

GSR measures electrical conductivity and sweat gland activity through electrodes attached to fingers, palms or soles of the feet. It measures stress, fear, anger and anxiety levels when exposed to marketing material or questioning, which is why it has been used as a method of lie detection! It measures intensity of emotional arousal, engagement and congruency of self-reports, but not what the feeling actually is. It’s also known as electrodermal activity (EDA) or skin conductance (SC).

EMG measures micro muscle movements in respondent’s faces through electrodes attached to the skin above two specific groups of facial muscles and these are used to determine emotional response. It measures emotional significance and responsiveness to stimuli. It can also be used to record muscle contractions in other areas of the body such as arms.

4. Heart Rate and Respiration

Electrocardiogram (ECG) measures heartbeats and rhythms through electrodes attached to the chest or sometimes limbs. It measures emotional arousal, stress and physiological activity, but is perhaps more commonly known for diagnosing cardiac disease.

5. Brain Activity 

The two most common technologies used for scanning brain activity are functional magnetic response imaging (fMRI) and electroencephalogram (EEG).

fMRI measures changes in blood flow and oxygenation as brain regions are activated during completion of cognitive tasks or when watching marketing materials. Respondents lie in a large oval-shaped magnet that takes images of brain activity when the respondent is exposed to the marketing stimuli. Maps are produced that show which parts of the brain are involved in particular mental processes. It measures emotional arousal and interest levels.

EEG measures changes in the electrical activity of the brain as cells become active to convey information through electrodes placed on the scalp. It measures changes in brain waves and can be used to measure instinctual emotions such as lust, anger and excitement as well as attention, motivation, interest and information about implicit memory processes.

But, they’re not the golden goose. Biometric technologies can help identify someone’s immediate emotional state through assessing their physical reaction to stimuli. Some have clear advantages over others. But no single approach provides all the answers. They work best in combination with each othe,r and with traditional survey methodologies to provide a more accurate and holistic view. It’s an emerging discipline, so watch this space!

The challenge of getting a brand noticed, remembered and then selected has never been so great in a world where a constantly distracted customer is only a swipe or click away from something far more interesting. Creating the right emotional response to capture the hearts and minds of customers is vital. Understanding what that is even more so. Yes, biometric research can be costly, but what price is that if it results in better decision-making, increasing the efficacy of your marketing strategies. Why not give it a try?

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