Index,D | Conductance ratios | Timing and spatial offset | ||||
---|---|---|---|---|---|---|
Ge: Pref/Null | Gi: Null/Pref | GD: Pref/Null | Ge: dT,(dX) | Gi: dT,(dX) | ||
On | 0.57 ± 0.08 | 1.66 ± 0.48 | 3.31 ± 2.15 | 0.70 ± 0.16 | 1 ± 54 msec | 42 ± 130 msec1-a |
(0 ± 27 μm) | (22 ± 63 μm) | |||||
Off | 0.55 ± 0.12 | 1.36 ± 0.131-b | 1.40 ± 0.31 | 0.94 ± 0.18 | −20 ± 67 msec | 303 ± 99 msec |
(−11 ± 32 μm) | (160 ± 56 μm) |
Values are quoted as the mean ± SD for the 16 cells. Pref, Preferred direction; Null, null direction; Index, the directional index, D, is defined by Equation 5; Conductance ratios, average ratios of the integrated conductance for the on- and off-responses. The integrals Ge andGi were calculated for the 16 cells over the limits shown by the solid lines under the records in Figure 4.GD = Ge +Gi, timing differences and derived spatial offsets: dX = v.dT/2, where v is the stimulus velocity and dT is the shift in the absolute peak-conductance time between the preferred and null directions. A positive value means that the temporal shift was equivalent to activation of inputs ahead of the stimulus during movement in the null direction.
↵F1-a Obtained from a subset of 9 of the 16 cells in which gi during preferred-direction stimuli displayed a peak early in the response.
↵F1-b The outlier off-response point (Fig.5C) is not included in this average. The average including this point is 1.54 ± 0.73.