Temporal activities of the top two neurons corresponding to different grasping targets. The light was on at time 0; the object was grasped around time 1 s and was held until time 2 s. (a) The first neuron. (b) The second neuron. In each block, the grasping target in the upper left plot is a cylinder. The target in the upper right plot is a plate. The target in the bottom left plot is a ring. The target in the bottom right plot is a cone. Neuron 1 fires more frequently when the target objects were the cylinder and the ring, while much less for the plate and the cone. The activity of neuron 2 clearly distinguished the group of cylinder and plate and the group of ring and cone. Furthermore, neuron 2 ceased to fire around time 1 s, which separated the reaching period and the grasping period [70].
