Whether it is what someone clicks on in their social media feed or what someone chooses to buy from a vending machine, consumers are incredibly difficult to predict because humans are different from each other.
Although consumers’ choices have long been regarded as puzzling mysteries, researchers have begun harnessing eye-tracking data to calculate an algorithm to quantify the nature of consumer decisions in a process called drift-diffusion model (DDM) .
The drift-diffusion model hinges upon the notion that economic choice is predictable and that behavioral outcomes can be calculated observing how long and frequent someone looks at something . According to Fabian Stelzer, CEO of EyeQuant, a company that uses eye-tracking software to predict viewer preferences, a consumer’s eye gravitates toward the most and least appealing regions of an interface, be it the Lifestyle page of The New York Times or the stream of photos and statuses on a Facebook newsfeed . Generally, people are more likely to perceive things that stand out; deviating from the norm, in both positive and negative ways, can attract attention.
Eye-fixation patterns can also measure the frequency of glances someone makes to a portion of a webpage and the duration of the focus on each design element. Companies like Visual Attention Service and RealEyes try to use these patterns to pinpoint the most appealing portions of a site .
A consumer’s perception and attention are contingent upon two factors: saliency and value. Saliency is correlated with the objective neuronal response triggered by a certain visual stimulant; value is the subjective individual significance prescribed to an experience of that object . Saliency tends to reflects human’s instinctual responses to a stimulus, whereas value, in this context, represents individual consumers’ desires.
Saliency is defined as the characteristic that makes an object stand out in comparison to others. Although processing the significance of an object is a complex mental process, generally, the hippocampus of the brain can assess saliency by comparing the observed stimulus to the subject’s past memories of the accepted normal . Saliency assumes that all humans make similar correlations with a certain product. In other words, recognition of the deviation from normal tends to be almost identical among most people. For example, for most people, the image of a house is likely to receive less attention than a graphic of a fire-breathing dragon.
The neural codes for perception are the nerve impulses to the brain, particularly in the region controlling visual processing. The pulvinar nuclei are located in the pulvinar thalamus of the brain, a region responsible for information flow to the cortex . Researchers believe the pulvinar nuclei control visual processing . These nuclei regulate saliency through attention selection, thereby affecting consumer preferences, since the object the eye is drawn to with most frequency and focus is the one the consumer is most likely to buy. Evidence of the pulvinar’s role in saliency includes physiological inspection, discernment between different visual stimuli, and behavioral changes triggered by pulvinar modulation .
Data to determine visual stimuli is measured from observing monitoring saccades, quick movements of the eyes in a certain direction. Saccades aid researchers in determining what catches the consumer’s eye, rather than simply what one happens to glance over. While in both cases, the consumer is seeing the product, saccadic eye-movement indicates that the viewing is deliberate rather than by chance.
The value a consumer puts on an object can affect the nature of saccadic eye-movement, since saccades are often reflections of consumer preference. Though saliency is the concept that both a shiny candy wrapper and a glittering diamond ring will catch a consumer’s eye, value is the concept that determines which product the consumer will desire more. To many, this will be the diamond ring; to a hungry child, the candy may carry more value. The subjectivity of value accounts for the differences in consumption of different products. Because a diamond ring company is unlikely to see consumers under the age of five, advertising techniques may differ from those of a candy company. The combination of value and saliency allows companies to tailor to their key demographic of consumers. By using technology to monitor attention given to a certain portion of a website, companies like EyeQuant are able to measure value for each individual consumer and compile data to derive a general evaluation of a website’s appeal .
Past examination of saccadic movement and experimentation with four models (saliency, value, additive combination of the two, and multiplicative combination) reveals that the relationship between consumers and their choices can be accounted for by a one to two ratio of saliency to value . While in this best-fit model, value appears to play a larger role in the choices of consumers, overlap between saliency and value is inevitable, given the indirect impression of showiness on consumer preference. This correlation can be favorable, as in the bright, attractive colors of a kite fluttering in the sky. The showiness can also be a disadvantage, as in an overly saturated family portrait among a collection of black and white stills. A consumer can only buy from what he sees, making it imperative for products to appeal to both saliency and value.
Recent studies on perceptual decision-making bear tremendous social implications in the world’s market population. The ability to predict consumer preferences enables companies to advertise directly to buyers, increasing effectiveness in the market.
The economic implications, however, branch far beyond the advertising. The development of the DDM model enables websites to shape consumer preferences through the layouts of their web pages, catering to the individual tastes of each client. While this is likely to increase market success for companies, there is controversy over the science of propaganda – especially with the idea of using privileged information about eye-movement and preferences to convince the consumer to make a certain purchase . The DDM model could determine trends by economic status, thereby aiding companies in price discrimination. Charging different groups different prices for an identical product allows companies to increase revenue by charging exactly what the consumer is willing to pay. Widespread implementation of such research techniques could result in tighter privacy regulation and full-disclosure warnings.
The DDM model extends into education as well. For instance, the model can identify portions of a textbook that students find particularly captivating, or determine the most distracting aspects of a classroom environment. In fact, the DDM model has the ability for one to access his or her subconscious desires and make informed decisions accordingly. When a consumer is presented with two options, eye-tracking can indicate which choice the consumer prefers based on instinct, even if he or she still feels unsure.
Due to popular application and potential for valuable psychological insight, the DDM paradigm sets the stage for further findings, identifying trends in human consumption.
Image Credit: Retrieved March 17, 2014 from: K2_UX. Heat Map of IKEA Fanpage. Photograph. Flickr. March 4, 2011. http://www.flickr.com/photos/k2_ux/5497506671/.  Retrieved March 17, 2014 from: SMI Eye Tracking. SMI BeGaze Eye Tracking Analysis Software. Photograph. Flickr. February 23, 2011. http://www.flickr.com/photos/ smieyetracking/5470335055/.