Figure 3.

Startle amplitude across trials before and after fear conditioning. For all vehicle-infused rats from Experiments 1 and 2, mean startle amplitudes for the first 20 trials of the Pre-Conditioning Test are shown, together with mean startle amplitude from all 20 trials of the Post-Conditioning Context Test. The difference between startle amplitude from the pre- to post-conditioning test is also shown, together with 95% confidence intervals (i.e., overlap of the error bars with 0 on the x-axis indicates that the difference for that trial was not statistically significant). The increase in startle from the pre- to post-conditioning context test was most pronounced during the first 2 min of the test, but by the fifth startle response had become unreliable.