Figure 4.

Experiment 2 results for preconditioning and the generalization test. (A) Mean skin conductance responses (SCR) are undifferentiated before fear conditioning, but a quadratic gradient that peaks before the most fear-intense stimulus emerges after fear conditioning. (B) Generalization across the three blocks of the generalization test shows a similar pattern across segments that habituate over time. (C) Reaction times (RT) are significantly faster for the S1 following fear conditioning. (D) Subjective face ratings are similar to those reported in Experiment 1. (E) Retrospective CS+ identification reveals a high percentage of subjects correctly identified the S3 as the CS+ post-experimentally. Error bars reflect standard error of the mean (SEM); (*) denote significant differences (P < 0.05); (μS) microsiemens.