Jerzy Konorski
Jerzy Konorski was a Polish neurophysiologist who further developed the work of Ivan Pavlov by discovering secondary conditioned reflexes and operant conditioning. He also proposed the idea of gnostic neurons, a concept similar to the grandmother cell. He coined the term neural plasticity, and he developed theoretical ideas regarding it that are similar to those proposed soon after by Donald Hebb.
Secondary conditioned reflexes
When he and Stefan Miller were medical students in Warsaw they proposed another type of conditioned reflex in addition to that discovered by Pavlov which was under the control of reward. This has come to be known as "type II conditioned reflexes," or secondary conditioned reflexes Type II conditioned reflexes are now known as operant or instrumental conditioning.He spent two years at Pavlov's laboratory as the result of a letter that he sent to Pavlov describing this work. Pavlov however was never convinced that instrumental conditioning differed in any important way from his own Type I conditioning.
An exchange between B. F. Skinner and Konorski also occurred over the two types of learning. Skinner had originally referred to operant conditioning as Type I and Pavlovian conditioning as Type II. Konorski agreed to revise his nomenclature to avoid confusion.
Neural plasticity
Konorski married the neurophysiologist Liliana Lubinska, who obtained her doctorate with Louis Lapicque. Konorski, Lubinska, and Miller established a laboratory at the Nencki Institute of Experimental Biology. With Konorski's knowledge of neurophysiology greatly expanded through his collaboration with Lubinska, he turned his attention to the neural mechanisms that underlie conditioning.Konorski asked how pre-existing connections between neurons in the brain could be changed by conditioning. He suggested an idea similar to Hebb in which coincidental activation in time causes the potential connections to be transformed into actual excitatory connections. Inhibitory connections arise when the excitation of one input coincides in time with a decease in its associated connection. He described the process: "The plastic changes would be related to the formation and multiplication of new synaptic junctions between the axon terminals of one nerve cell and the soma of the other" This idea that synapses strengthen with use was also proposed in the West in the theory of Hebbian synapses by Donald Hebb.