The startle reflex is a brainstem reflectory reaction (reflex) that serves to protect vulnerable parts, such as the back of the neck (whole-body startle) and the eyes (eyeblink) and facilitates escape from sudden stimuli. It is found across the lifespan of many species.

Where is startle reflex found?

The startle reflex is a rapid, generalized motor response to a sudden, surprise stimulus. The most extensively studied human startle response is that which occurs to loud noises. It is an oligosynaptic reflex mediated in the brainstem. The startle response is distinctive on EMG testing with surface electrodes.

How do you check your startle reflex?

Your baby's health care provider will check for this reflex right after birth and during well-child visits. To see the Moro reflex, the child will be placed face up on a soft, padded surface. The head is gently lifted with enough support to just begin to remove the body weight from the pad.