Startle reflex

Startle Reflex

The Startle Reflex, also known as the Moro Reflex, is an involuntary, automatic response to sudden or threatening stimuli. It is one of the many Primitive Reflexes that are present at birth and typically disappear within the first few months of life.

Overview

The Startle Reflex is characterized by a sequence of movements: the infant will suddenly extend the arms and legs, spread the fingers, and then bring the arms back to the body. This reflex is usually triggered by a sudden change in the environment, such as a loud noise or a change in position.

The Startle Reflex is thought to have evolved as a protective mechanism, allowing infants to react quickly to potential threats. It is also believed to play a role in the development of the infant's nervous system.

Development and Disappearance

The Startle Reflex is present at birth and is usually most pronounced during the first month of life. It gradually diminishes and typically disappears by the age of 6 months. However, in some cases, the reflex may persist into adulthood, a condition known as Hyperexplexia.

The disappearance of the Startle Reflex is an important milestone in the development of the infant's nervous system. It indicates that the brain is maturing and taking over the control of movements from the primitive reflexes.

Clinical Significance

The presence or absence of the Startle Reflex can provide important information about the health and development of an infant. A lack of this reflex in a newborn, or its persistence beyond the normal age range, may indicate a neurological problem.

In adults, an exaggerated Startle Reflex can be a symptom of several neurological disorders, including Post-Traumatic Stress Disorder (PTSD), Generalized Anxiety Disorder (GAD), and certain forms of epilepsy.

See Also

• Primitive Reflexes
• Moro Reflex
• Hyperexplexia
• Post-Traumatic Stress Disorder
• Generalized Anxiety Disorder