Figure 4. Psychometric functions and neurometric functions obtained from the clockwise-counterclockwise discrimination task with (A) bars, (B) dot patterns, and (C) random dot displays (with 100% coherence) delivered to the fingertip.

The neurometric functions were derived from the responses of the neurons that exhibited significant direction tuning to bars, dot patterns, and random dot displays. A positive Δϕ denotes a clockwise rotation. As can be seen, the direction information carried by these neurons can account for the perceived direction of the stimuli. (D) Psychometric and neurometric functions obtained for the left-right discrimination task with random dot displays varying in coherence. Again, the responses of directionally selective area 1 neurons could account for perception.