[Role of the amygdala in the evaluation of the biological significance of conditioned stimuli].

Lesions of the amygdala in cats and dogs prevent some animals to respond adequately to signals of different biological significance; the amplitudes and probabilities of EPs appearance in the sensomotor cortex lose their maximums at 0.8 and 1.6 frequencies within the range of 2.0 to 3.0 kHz which are formant ones of some communication signals in cats. Rendering an indifferent stimulus a signal, i. e. food significance, becomes reflected in the amygdala neuronal activity, the amygdala starting to respond to the signal as if it were an unconditioned stimulus. The data obtained are used to discuss the role of amygdala in assessment of conditioned stimuli biological significance as well as in differentiation of incoming afferent influences.