Figure 9.

Network performance during orientation discrimination. Panels a-h show all 25 output responses, as driven by the GM neurons (not shown), in single trials. Continuous lines indicate intended target location (-10 or +10); dashed lines indicate the center of mass of the output activity. Right and left columns have identical stimuli and conditions, but with (α = 1) and without (α = 0) noise, respectively. A trial is deemed correct if the higher peak of activity is situated at the intended target location. a: Single trial with x = 5°, y = 1 and error = 0.15. b: As in a, but error = 0.001. c: Single trial with x = 1°, y = 1 and error= 6.7. d: As in c, but error = 12.2. The response is scored as incorrect because the tallest hill of activity is not at the intended target. e: Single trial with x = 1°, y = 2 and error = 6.7. f: As in e, but error = -2.9. g, h: No-go trials. i: Probability of making a movement to the right target as a function of stimulus orientation, in condition 1 (y = 1) and with noise. Gray lines are fits to the simulation data. The center point or bias of the fit is indicated by the dashed line and is equal to -0.06°. Discrimination threshold is 1.5°. j: As in i, but with the association between orientation and targets reversed (y = 2). The center point is -0.04°; the discrimination threshold is 1.4°.