Valls-Sole, "Assessment of excitability in brainstem circuits mediating the blink reflex and the startle reaction
," Clinical Neurophysiology, vol.
Some psychologists believe that the startle reaction
, which has been examined by numerous researchers since 1939, lies at the far end of the emotion of surprise and provides a good model for the study of other emotions.
Sudden shocks - either building emotional terrors or simple startle reactions
, cause stress hormones to pour out, messing with the heart's rhythm, putting more stress on certain parts of the arteries or muscles, or poisoning the muscles entirely.
Because circuits involved are shorter, the latencies of the startle reactions
are much shorter than those of voluntary reactions.
In most cases, symptoms of the ailment, including unwanted memories of violent events, startle reactions
to sudden noises, and troubled relationships, first appear after a person launches a career in war coverage, Feinstein and his colleagues report in the September American Journal of Psychiatry.