Table 1.

Summary of the jumps experiments

	8°/sec (4°)	8°/sec (1°)	2°-jumps (4°)	133°/sec (4°)	l
Monkey Mo (right, 1st)1-a	118° /sec2	109° /sec2	165° /sec2	367° /sec2	0.81
Monkey Ka (right)1-a	106° /sec2	110° /sec2	123° /sec2	245° /sec2	0.87
Monkey Qu (right)	69° /sec2	112° /sec2 1-b	116° /sec2	392° /sec2	0.85
Monkey Qu (left)	55° /sec2	109° /sec2 1-b	97° /sec2	322° /sec2	0.84
Monkey Qu (up)	29° /sec2	46° /sec2	67° /sec2	125° /sec2	0.61
Monkey Qu (down)	43° /sec2	60° /sec2	51° /sec2	184° /sec2	0.94
Monkey Mo (right, 2nd)	78° /sec2	98° /sec2	112° /sec2	460° /sec2	0.91
Monkey Mo (left)	78° /sec2	104° /sec2 1-b	101° /sec2	490° /sec2	0.94
Monkey Mo (up)	54° /sec2 1-b	72° /sec2	59° /sec2	136° /sec2	0.94
Monkey Mo (down)	61° /sec2 1-b	87° /sec2	67° /sec2	324° /sec2	0.97
Physiology (peak response)	6.4°/sec		8.7° /sec	22.8° /sec	0.86

From left to right, the columns show data for: the control 8°/sec target starting at 4° eccentric from fixation, the control 8°/sec target starting at 1°, the 2°-jumps target starting at 4°, the control 133°/sec target starting at 4°, and the value of l computed from Equation 2. The top 10 rows report eye acceleration during the initiation of pursuit for target motion in different directions, using different monkeys or recorded on different days. For some experiments using vertical directions, initial pursuit was weak, and it was necessary to increase the starting eccentricity of the targets to reduce the prevalence of early saccades. For these experiments, the eccentricity of all targets was increased by 1 or 2°. Relative eccentricities remained unchanged. The bottom row gives the target speed reconstructed for each target type from the population response recorded in area MT.

^F1-a Data shown in Figure 3.

^F1-b No significant difference between the responses to the indicated control 8°/sec target and the 2°-jumps target (paired t test).

All measurements were based on averages of at least 50 trials.