The chronometry of single neuron activity: Testing discrete and continuousmodels of information processing

The authors propose to study information transmission by comparing the effe cts of experimental factors on reaction time (RT) with the latency of the c hanges in activity of single-neurons. An experiment was conducted in which a monkey (Macaca mulatta) performed a tactile-manual 2-choice RT task and t he compatibility of the stimulus-response mapping was manipulated. Task-rel ated neurons were recorded in the monkey's primary somesthetic and motor co rtices. The changes in activity of 105 of these neurons were classified eit her as sensory-like or as motor-like. The sensory-like changes occurred bef ore the motor-like ones. The stimulus-response mapping exerted its entire e ffect on the RT after the sensory-like changes and before the motor-like on es. These findings suggest that the information was transmitted discretely from the processes affected by the mapping to the processes implemented by the motor-like changes.