Typically known from the golden Hollywood era of suspense noir gangster films, for many of us GSR is strongly linked to criminals sitting in a shady backyard room hooked up to a polygraph.
In real life (and actual research), however, there is much more to GSR methodology than outmoded polygraph testing. Dare to tap into the unconscious and learn what triggers emotional behavior: Why is it that some things more than others make us chuckle or give us the creeps, drive us up the wall or let us dance for joy?
Are you frightened just thinking about heights? Are you smitten by newborn babies? Does the pure sight of spiders make your heart beat faster?
GSR can tell.
Our skin spills everything
Our skin gives away a lot of information on how we feel when we’re exposed to emotionally loaded images, videos, events, or other kinds of stimuli – both positive and negative. No matter whether we are stressed, nervous, fearful, psyched up, stoked, baffled, or surprised – whenever we are emotionally aroused, the electrical conductivity of our skin subtly changes.
One of the most sensitive measures for emotional arousal is Galvanic Skin Response (GSR), also referred to Skin Conductance (SC).
GSR originates from the autonomic activation of sweat glands in our skin. The sweating on hands and feet is triggered by emotional stimulation: In emotional situations, bodily processes are triggered automatically – our heart beats faster, the pulse rises, hands become sweaty.
To put it bluntly: While we are physiologically or psychologically aroused (in fear, excitement or under stress), we start to sweat.
Yes, you heard right. Here’s why:
Our body has about three million sweat glands. The density of sweat glands varies markedly across the body, being highest on the forehead and cheeks, the palms and fingers as well as on the sole of the feet.
Whenever sweat glands are triggered and become more active, they secrete moisture through pores towards the skin surface. By changing the balance of positive and negative ions in the secreted fluid, electrical current flows more readily, resulting in measurable changes in skin conductance.
While the primary purpose of sweat emission is thermoregulation (and that’s probably the first thing crossing your mind), sweating – particularly on hands and feet – is triggered whenever we’re emotionally aroused. You surely know how your hands feel cold and clammy when you‘re terrified. Just imagine an „all or nothing“ exam situation for which you are super ill prepared. Take a minute and recall that moment of defeat in the auditorium. Yup, exactly – just thinking about it gives you the chills and sweaty hands.
Now what exactly makes GSR such a valuable biometric signal in assessing emotional behavior?
Here are our three reasons why GSR should definitely make it onto your list of biosensors.
Reason 1: Peek beneath the surface to reveal unconscious behavior
With GSR, you can tap into unconscious behavior that is not under our cognitive control. Skin conductivity is solely modulated by autonomic sympathetic activity that drives bodily functions, cognitive and emotional states as well as cognition on an entirely subconscious level. Like other vegetative auto-regulatory processes (body temperature, heart rate, blood pressure, gut motility etc.), sweat secretion cannot be controlled consciously. Rather, it is driven and balanced by our autonomic nervous system in order to meet behavioral demands (to prepare and execute energetic movement, for example).
Emotional experiences elicit changes in autonomic arousal quite impressively. Exactly this circumstance renders GSR the perfect marker for emotional responses as it offers undiluted insights into physiological and psychological processes of a person.
Reason 2: You can test any kind of stimulus
With GSR, the impact of any emotionally arousing content, product or service can be tested: Actual physical objects, videos, images, sounds, odors, food probes and other sensory stimuli as well as thought experiments and mental images. This makes for a tremendously wide variety of application possibilities in psychological and clinical research, psychotherapy, consumer neuroscience and marketing, media and advertisement testing as well as usability, UX design, and many more. Live out your biometric research frenzy and go wild on testing – GSR is the perfect match.
Reason 3: Setup and measurement are easy
In case you are thinking bulky equipment, think again. In fact, GSR devices are quite the opposite: They typically consist of two small electrodes (snugly attached to the fingers, palms or feet), an amplifier to boost the signal amplitude, and a digitizer to transfer the analog raw signal into binary data streams. That’s it.
With minimal preparation times and cleanup, skin conductivity is recorded non-invasively. This renders GSR measurements a lot more comfortable for respondents compared to other neuro-methods such as fMRI or EEG, where longer preparation and calibration phases are quite common (and mostly a hassle).
Curious to learn more about GSR and how you can advance your insights into emotional behavior?
Go get the rest of our smart tips and download our brand-new definite guide to GSR packed with everything you need to know to get up to speed with GSR methodology and data analysis. From the basics to the fine print – we’ve got you covered, whether you’re a newbie or an old hand in research.