Startle-evoked movement

A Psychophysics Experiment on the Control of Reaching Movements

Startle-evoked movement

Startle-evoked movement refers to the involuntary motor response triggered by a sudden, unexpected stimulus. This phenomenon is commonly observed in both humans and animals and serves as a protective mechanism to react quickly to potential threats in the environment.

Physiology

The startle reflex is a primitive, innate response that involves a rapid contraction of muscles in response to a sudden stimulus. This reflex is mediated by the brainstem and involves a complex neural circuitry that coordinates the motor response.

Mechanism

When a startling stimulus is detected, sensory information is rapidly transmitted to the brainstem, specifically the reticular formation, which then activates motor neurons to produce the startle-evoked movement. This process bypasses higher brain centers, leading to a quick and automatic response.

Clinical Significance

Startle-evoked movements can be exaggerated or diminished in certain medical conditions. For example, individuals with anxiety disorders may exhibit heightened startle responses, while those with certain neurological disorders may show a blunted startle reflex.

Research

Studies on startle-evoked movement have provided insights into the underlying neural mechanisms of the startle reflex and its modulation. Researchers have used techniques such as electromyography and neuroimaging to investigate the neural pathways involved in the startle response.

See also

• Reflex
• Neurology
• Psychology

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