Correlates of lexical processing in the activity of neuronal populations of the human brain

Evoked discharge rate variations in the populations of subcortical (mainly striopallidal and thalamic) neurons in man during lexical processing were studied. The neuronal activity of 165 populations was recorded as a part of the diagnostic procedures in 16 parkinsonian patients treated with implanted electrodes. The patients were performing a set of psychological test involving perception and simple operations with visually presented words and pictures. A class of neuronal reactions is described which reflect endogenous brain processes associated with inner speech.