Role of conceptual knowledge in learning and retention of conditioned fear

Abstract

Associating sensory cues with aversive outcomes is a relatively basic process shared across species. Yet higher-order cognitive processes likely contribute to associative fear learning in many circumstances, especially in humans. Here we ask whether fears can be acquired based on conceptual knowledge of object categories, and whether such concept-based fear conditioning leads to enhanced memory representations for conditioned objects. Participants were presented with a heterogeneous collection of images of animals and tools. Objects from one category were reinforced by an electrical shock, whereas the other category was never reinforced. Results confirmed concept-based fear learning through subjective report of shock expectancy, heightened skin conductance responses, and enhanced 24h recognition memory for items from the conditioned category. These results provide novel evidence that conditioned fear can generalize through knowledge of object concepts, and sheds light on the persistent nature of fear memories and category-based fear responses symptomatic of some anxiety disorders.

Figure 1

Behavioral results. (A) Participants rated expectancy for the US higher on CS+ trials versus CS− trials, and there was no effect of category (tool or animal) on US expectancy ratings. (B) Differential ratings of US expectancy emerged early during training. Dashed line indicates chance level of certainty as to whether or not the US would be delivered. (C) Differential SCRs were observed between CS+ and CS− items, and there was no effect of category (tool or animal) on differential SCRs. (D) 24-hour delayed recognition memory for CS+ items was significantly greater than that for CS- items, and these effects were not driven by which category served as the CS+ or CS−. Error bars reflect ± standard error (SEM). ** = p < .001.