Fig. 15.

A schematic diagram to depict the early and late components of the typical normal human startle response. The sequence of muscle recruitment consisting of the orbicularis oculi (OO), the sternocleidomastoid (SCM), masseter (MA), biceps (Bi), abductor pollicis brevis (APB) and quadriceps (Qu) can be seen with a latency to onset between 20 and 150 ms. No electromyographic (EMG) activity is visible in the period between the early and late response (200–400 ms). No typical muscle recruitment exists for the late response lasting up to 3–10 s, as this is thought to be complex autonomic behavior. Created with BioRender.com. Based on (Saini and Pandey, 2020).