Читать книгу Social Psychology - Daniel W. Barrett - Страница 88

When you are nervous or anxious, does your heart beat a little faster and do you sweat a bit more? Well, early research in physiological psychology focused primarily on measuring relatively obvious overt bodily responses to situations and stimuli. One of the most researched psychophysiological constructs targeted by social neuroscience was arousal (Cacioppo, Berntson, & Crites, 1996). When we are physiologically aroused, we typically experience increased heart rate, blood pressure, pupil dilation, and sweating. The primary method for assessing arousal was the measurement of skin conductance or galvanic skin response (GSR). GSR—more recently labeled electrodermal activity or EDA—is used as a measure of arousal, because arousal induces the individual to produce a small amount of sweat, even if that person cannot detect it (Mendes, 2009).

Typically, two electrodes are placed on the hand, a weak electrical current is applied, and the time it takes for the electricity to pass from one electrode to the other is measured. An increase in skin conductance (faster transmission of current across the skin) occurs when a person sweats and suggests that the person is aroused (unless her hand is moist for some other reason). The polygraph or lie detector measures GSR and other indices of arousal but is famously unreliable as way to determine the veracity of a person’s testimony or answers. The primary reason for this is that a person’s arousal could be caused by any number of factors, only one of which is lying (see Chapter 5 for more on lie detection). For instance, a person may become aroused simply because he is being asked about whether he is lying.