Table 1.

Number of responding neurons in different behavioral task phases

	Responding neurons	Non-reward predicting, non-direction sensitive	Reward predicting only	Direction sensitive only	Both direction sensitive and reward predicting
Cue display	28/32	10/28 (36%)	2/28 (7%)	3/28 (11%)	13/28 (46%)
	20/29	15/20 (75%)	3/20 (15%)	0/20	2/20 (10%)
Post-cue interval	31/32	8/31 (26%)	2/31 (6%)	13/31 (42%)	8/31 (26%)
	23/29	14/23 (61%)	1/23 (4%)	5/23 (22%)	3/23 (13%)
Reaction and movement	25/32	7/25 (28%)	2/25 (8%)	15/25 (60%)	1/25 (4%)
	22/29	12/22 (54%)	1/22 (5%)	9/22 (41%)	0/22
Reward-delay period	31/32	11/31 (36%)	2/31 (6%)	12/31 (39%)	6/31 (19%)
	23/29	13/23 (57%)	0/23	9/23 (39%)	1/23 (4%)

Activity of responding neurons, in the different phases of the task, is modulated by reward prediction, direction of movement, both of these parameters, or neither of them. A single neuron may be modulated by different parameters in different phases of the task and thus could be counted more than once. The neurons in each phase are also sorted by monkeys (monkey Y, top lines; monkey C, bottom lines).