Top: Raster plots of the activity of an M1 neuorn during 5 movements in 8 different directions in a 2D plan, Bottom - the directional tuning curve for the same neuron, centered on its preferred movement direction, calculated from the mean discharge rate of neuron from the appearance of the target to the end of movement. Adapted after "The representation of movement direction in the motor cortex: Single cell and population studies" by AP Georgopoulos, JF Kalaska, MD Crutcher, R Caminiti, JT Massey. In Dynamic Aspects of Neocortical Function, eds Edelman, 1984