Reflex

The signal is then transferred across the synapse to a motor neuron, which evokes a target response.

These neural signals do not always travel to the brain,[4] so many reflexes are an automatic response to a stimulus that does not receive or need conscious thought.

These automatic reactions to stimuli enable infants to respond to the environment before any learning has taken place.

Processes such as breathing, digestion, and the maintenance of the heartbeat can also be regarded as reflex actions, according to some definitions of the term.

In reality, however, most reflexes are flexible and can be substantially modified to match the requirements of the behavior in both vertebrates and invertebrates.

During voluntary movements, however, the intensity (gain) of the reflex is reduced or its sign is even reversed.

Descartes introduced the idea in his work "Treatise on Man", published posthumously in 1664.

He described how the body could perform actions automatically in response to external stimuli without conscious thought.

Descartes used the analogy of a mechanical statue to explain how sensory input could trigger motor responses in a deterministic and automatic manner.

Hall's significant work on reflex function was detailed in his 1833 paper, "On the Reflex Function of the Medulla Oblongata and Medulla Spinalis," published in the Philosophical Transactions of the Royal Society, where he provided a clear account of how reflex actions were mediated by the spinal cord, independent of the brain's conscious control, distinguishing them from other neural activities.