Fig. 4.

Circa-strike defense: Reactivity to white noise in stress context. a The stressed group showed increased baseline freezing during the first three minutes in Context A (***p < 0.001). Open symbols represent females, closed symbols represent males although there were no significant sex effects or interactions. b Stress group showed robust freezing in Context A between trials of 75 dB white noise (***p < 0.001 Stress vs. No Stress). c Prior stress increased reactivity to trials of 75 dB white noise as measured by peak activity ratio. The no-stress group showed little reactivity to white noise. (***p < 0.001 Stress vs. No Stress.) d No differences between groups for dart rate across noise trials. e Micro bins (0.533 s) velocity traces for pre-stimulus, noise, and post-stimulus period averaged for the first four trials. Prior stress reduced velocity during pre-stimulus period and robustly increased peak velocity at onset of noise period. f Velocity traces averaged for all 16 trials of session. e, f Note similar patterns for groups across stimulus periods and differences in magnitude between early session (e) and whole session (f). The shaded area represents the 10-s noise period