 Early work suggested that the activity of a single neuron provides a strong correlate of the animal’s visually guided performance. This can be seen by plotting both the animal and the neuron’s performance across different stimulus values. In these experiments, the value concerns the percent coherence of motion of a set of dots defined as the number of dots moving in the same direction (0% coherence being random motion; 100% being all dots moving in the same direction). In the first case, we construct a psychometric curve that plots the animal’s percent correct reports relative to percent coherence of motion of the stimuli. As one might expect, percent correct reports drop as coherence drops, and the inflection point reflects where the subject is equally likely to indicate left or right motion. We can do the same for the neural activity of the neuron across the same stimulus values, a neurometric curve.