The Effect of Avoidance Behavior on Generalization of Threat-Expectancy

The excessive spreading (or generalization) of fear toward safe situations is characteristic of anxiety disorders. Understanding factors that contribute to this is crucial. The current study hypothesized that avoidance leads to increased generalization; relentless avoidance may blur the perceptual memory of the avoided situation, thereby increasing the perceived similarity of this situation with novel situations, increasing generalization. To test this fundamental hypothesis, we conducted a serial fear conditioning experiment, using a convenience sample primarily composed of students. During fear acquisition, a geometric shape (preCS+) predicted a colored lamp (CS+), which was followed by an aversive electrical stimulus (US). Another geometric shape (preCS-) predicted another colored lamp (CS-), which was never followed by the US. Next, one group of participants avoided the CS+ and US by performing a response on the preCS+. Another group could not avoid, but saw a signal indicating no US would follow. During generalization, new lamp colors were presented (GSs); the avoidance group was more likely to identify a stimulus as CS+ during generalization, whereas the control group was more likely to identify a stimulus as GS. Importantly, when a stimulus was identified as CS+, the avoidance group showed higher US-expectancy compared to the control group. When a stimulus was identified as GS however, the avoidance group showed lower US-expectancy. Results thus partially supported that avoidance increases generalization, as this was dependent on stimulus identification. The current study is the first to show that avoidance may contribute to excessive fear through biased memory and perception.