Formation and inhibition of conditioned reflexes
A conditioned reflex forms during life on the basis of an unconditioned one and is individual. Pavlov experimented on dogs: when food is given, saliva flows (unconditioned reflex). When a light was switched on shortly before feeding and this was repeated several times, the light alone caused salivation. Now the light is the conditional stimulus, a signal, and food is the reinforcing unconditioned stimulus. The centre of conditioned reflexes is in the cerebral cortex; they underlie knowledge, skills, reading, writing and habits. Conditioned reflexes can be inhibited. In external inhibition a strong or new stimulus (a loud noise) stops the reflex. In internal (extinction) inhibition, if the signal is repeatedly not reinforced the reflex fades; hence knowledge that is not repeated is forgotten, though a trace remains and relearning is easier. Harmful habits too can be gradually extinguished through proper behaviour and support.
Conditioned reflex scheme: draw the sequence “signal → food → saliva”; then show on a card how the reaction fades when there is “a signal but no food”. Do not experiment on animals.