Where does reflex collide?

An involuntary, stereotyped response produced when a stimulus travels through a fixed neural pathway, the reflex arc, from sensory receptor to motor effector without waiting on a conscious decision: the tap below the knee that jerks the leg is the familiar example. Sherrington's 1906 The Integrative Action of the Nervous System treated the reflex as the unit of nervous action and showed how such arcs are coordinated, inhibited, and combined. The referent is a wired-in bodily response to a stimulus, not a habit learned by pairing, an angle that turns past a straight line, or a mirror inside a camera.[1]

Unit

An involuntary motor response to a stimulus, carried by a fixed sensory-motor arc

Recovery means

The arc resets as the stimulus passes and the muscle returns to rest, ready to fire again on the next tap

Measured by

Elicited clinically by a tendon tap and graded by the briskness of the response, or recorded by electromyography and reflex latency

A reflex response that has been transferred to a formerly neutral stimulus by repeatedly pairing that stimulus with one which already evokes the response: after a bell is sounded before food often enough, the bell alone comes to draw the reflex. Pavlov's 1927 Conditioned Reflexes reported this in salivating dogs and set out the pairing, extinction, and recovery of such learned reflexes. The referent is a response acquired through experience, built on the innate reflex but not identical to it, and unrelated to a turning angle or a camera's mirror.[2]

Unit

A response transferred to a formerly neutral signal by pairing, in learning

Recovery means

The response extinguishes when the signal is repeated without reinforcement, and can return in spontaneous recovery

Measured by

Quantified by the magnitude and latency of the conditioned response, such as the drops of saliva drawn by the signal alone

An angle whose measure is greater than 180° and less than 360°, that is, one that turns back past a straight line without completing a full revolution: the larger of the two angles that a pair of rays cuts the plane into, when neither is straight. Clapham and Nicholson's The Concise Oxford Dictionary of Mathematics gives this standard definition, distinguishing the reflex angle from acute, right, obtuse, and straight angles. The referent is a magnitude of rotation in the plane, measured in degrees or radians, and it has nothing to do with a bodily response, a learned habit, or a camera.[3]

Unit

An angle between 180 and 360 degrees, measured in degrees or radians

Recovery means

Not applicable

Measured by

Read with a protractor, or found as 360° minus the corresponding non-reflex angle