Reflection of the operations of comparison of current afferentation with internal pretuning in the impulse activity of neurons of the frontal cortex of the dog.

When the differentiation of the classical (salivary) conditioned reflex (CR) is carried out by dogs, two groups of neurons are distinguished in their frontal cortex, for which a specific type of relationships between the current conditional and unconditional (CS and US) signals and the character of the internal pretuning to the perception of the given stimuli is the condition. The reactions of the neurons of the first group developed in response to the US only when the tracking schedule of the US was characterized by regularity. These reactions disappeared when there was any sudden deviation from the standard schedule of the of the CS-US combination for the animal, or when there was a change in the parameters of these signals, and they recovered as the repeated presentations of the CS or the US with the changed parameters proceeded. The reactions of the neurons of the second group developed in response to the presentation of the CS only when this stimulus followed a stimulus which was opposite to it in significance. The reactions of the neurons of the first group are associated with the processes of the detection of the correspondence of the sensory pretuning to the actual stimulus, while the reactions of the neurons of the second group are regarded as the result of the disparity between the characteristics of the current afferentation and the "internal model" of the stimulus.