Table 1.

Psychophysical performance for RT and FD experiments

Monkey	αRT Mean ± SEM	βRT Mean ± SEM	n	αFD Mean ± SEM	βFD Mean ± SEM	n	αRT/αFD
N	6.82  ± 0.49	1.45  ± 0.09	31	9.11  ± 0.85	1.65  ± 0.17	25	0.77
B	7.97  ± 0.47	1.62  ± 0.10	23	10.92  ± 1.00	1.66  ± 0.18	13	0.69

Average values of threshold (α) and slope (β) from Equation 1(mean ± SEM, based on n experiments) are shown for each monkey. The ratio, α_RT/α_FD, is derived from experiments in which data were obtained for both RT and FD conditions. For both monkeys, the geometric mean of α_RT/α_FD was <1 (p = 0.002; paired t test after log transform).