Fear generalization in humans: impact of prior non-fearful experiences

Fear generalization lies at the heart of many anxiety problems, and is therefore an important target for prevention and/or treatment. Here, we investigated whether fear generalization towards a specific stimulus can be weakened by prior non-fearful experiences with that stimulus. Using the standard human fear conditioning procedure, all participants received paired presentations of a geometric figure and an electric shock. This was followed by a test phase in which a similar but different figure was presented. Electrodermal responding and ratings of shock-expectancy measured the level of fear generalization towards this test stimulus. Crucially, half of the participants had been preexposed to that stimulus (without shock). The results show significantly less generalization in this group, suggesting that prior non-fearful experiences can protect against fear generalization. These results may inspire novel ways to prevent the development of clinical anxiety.