How the Body Informs Design
In the last blog post, I addressed the definition of psychophysiology, "the scientific study of social, psychological, and behavioral phenomena as related to and revealed through physiological principles and events in functional organisms," (Cacioppo, Tassinary, and Bertston, 2007). Now I turn to a very basic overview of how psychophysiological recordings and measurements give rise to marketing insights. Robert M. Stern, William J. Ray, and Karen S. Quigley succinctly articulate in Psychophysiological Recording (2001) that psychophysiologists measure the "functioning of neurons, muscles, and glands." As neurons, muscles, and glands become active in response to a stimulus, like watching a horror movie on Halloween, they signal the nervous system to communicate to the brain and the rest of the body. When electrodes are placed on the skin, they are able to pick up on these electrical signals. For example, electrodes on the forearms, chest, legs, or near the collar bones record heart rate. Electrodes on the palms of the hands or bottoms of the feet measure electrical activity at the skin surface in response to sweat, or skin conductance. Electrodes at numerous sites throughout the body measure electrical impulses resulting from muscle movement. Surface electrodes on the scalp, or EEG, measure electrical activity as neurons fire in the brain. In addition to measuring electrical signals only, psychophysiologists might also record biochemical changes, such as shifts in hormone levels, through blood or saliva assays. They might look at blood oxygen levels through magnetic resonance imaging (MRI). As technology and measurement tools become more refined and sensitive, new methods will be implemented to record physiological activity.
Experimentation over time has yielded repeated patterns of physiological responses in connection with psychological events and has formed the basis for psychophysiology. Ideally, psychophysiologists would like to find a one-to-one correlation in the interactions between a physiological response and a psychological phenomena. It would be nice to say that an increase in heart rate means someone is aroused; however, this is not necessarily the case. The body and mind are complex and influenced by numerous internal and external stimuli all the time. Thus, researchers use the patterns observed from multiple bodily responses, such as heart rate, skin conductance, and facial muscle movements, to draw conclusions about psychological concepts like cognitive and emotional processing, attention, arousal, engagement, memory, and motivation – just to name a few.
Recording and analyzing patterns of physiological responses to consumer products and marketing materials allows HCD to determine what design features have stopping power, engage viewers, make consumers feel positive and remember what they see and hear.
In upcoming posts, I will describe some of the physiological patterns associated with arousal, emotion, attention, and more. Next week, HCD Insights will present daily highlights from the Society for Psychophysiological Research’s annual conference in Florence, Italy.