. Author manuscript; available in PMC: 2013 Sep 19.

Published in final edited form as: J Vis. 2006 Oct 13;6(11):1159–1171. doi: 10.1167/6.11.2

Table 1.

Spatial filter characteristics and the spatial summation parameters from the predicted spatial summation functions for different spatial filters.

Spatial filters	Spatial bandwidth (octaves)	Orientation bandwidth (deg)	Space constant of the orthogonal Gaussian (deg)	Log critical area (log deg²)/critical diameter (deg)	Extended slope
D1 long	2.6	34	0.11	–1.6/0.18	0.15
D1 short	2.6	120	0.45	–1.6/0.18	0.13
D2 long	1.8	24	0.16	–1.5/0.19	0.19
D2 short	1.8	90	0.64	–1.6/0.18	0.13
D6 long	1.0	14	0.28	–1.4/0.23	0.24
D6 short	1.0	54	1.10	–1.5/0.20	0.15
DoG 4×	1.9	–	–	–1.6/0.18	0.13
DoG 2×	2.4	–	–	–1.7/0.16	0.11
DoG 1×	3.2	–	–	–1.7/0.16	0.11
Gaussian no surround	Low pass	–	–	–1.6/0.18	0.27

Receptive fields and tuning functions of the filter-elements are shown in Figure 1, and the predicted spatial summation functions are shown in Figure 2. All examples are for filters with a peak spatial frequency of 2 cpd.