1. Seeing motion : From neural circuits to perceptual decisions

2. From D. Hubel, 1995

21. Where do we go from here???

23. Sensory representation of motion Pre-oculomotor circuitry Oculomotor circuitry Abstract decision representation?? ??

32. An Eye Movement Matching Task

38. 10 sec 30 sec independent, Poisson processes (constant rate) 30 sec10 sec An Eye Movement Matching Task

39. Matching: response ratio = reward ratio 10 sec 30 sec independent, Poisson processes (constant rate) 30 sec10 sec 25% 75% An Eye Movement Matching Task

40. Matching: response ratio = reward ratio frequent unsignaled changes in reward ratio 10 sec 30 sec independent, Poisson processes (constant rate) 30 sec10 sec 25% 75% An Eye Movement Matching Task

41. 1:1 1:3 3:1 1:1 1:6 6:1

42. Crosscorrelograms Correlation Coefficient Lead (responses)

43. “Experienced value” (EV) = (weighting function) X (reward history)

44. Area LIP in the Macaque Brain http://www.loni.ucla.edu/data/monkey LIP

45. Time (msec) Response (peak normalized) Targ onSac Firing rate is related to experienced value (n=21) 02004006000-200-400-600 0 0.2 0.4 0.6 0.8

46. 2. EV is represented in LIP, and the effects are often as large as those of the eye movement itself. EV is NOT computed in LIP. Conclusions - Experienced Value (EV) 1. Under our conditions, EV is computed within a relatively short time window, extending no more than 5-10 trials into the past.

47. 3. At least one of these brain structures (area LIP) represents additional decision variables such as the previously experienced value of alternative actions. General Conclusions 1. We have established a causal relationship between the sensory representation of motion direction in the cortex and perceptual judgments of motion. 2. Candidate neural correlates of the decision process exist in at least three pre-oculomotor areas of the frontal lobe, parietal lobe and the upper midbrain. Causality is not yet established between these neural circuits and behavioral decisions. (We’re working on it!)

48. Indeed there are now no logical (and I believe no Insurmountable technical) barriers to the direct study of the entire chain of neural events that lead from the initial central representation of sensory stimuli, through the many sequential and parallel transformations of those neural images, to the detection and discrimination processes themselves, and to the formation of general commands for behavioral responses and detailed instructions for their motor execution. V. B. Mountcastle, Handbook of Physiology, 1985