Table 1.
Results for parameter robustness checks. For each new parameter value in turn, 100 psychometric functions were generated. The numbers in the columns headed `Threshold' and `Slope' refer to the median of the values from those 100 runs. Values are given in units of % contrast. For details on the meaning of the individual parameters, and the abbreviations used, see the Methods section. For quick comparison, the equivalent results using the standard parameter values as given in the Methods section are included at the top of the table.
| Parameter | Default value | New Value | Threshold | Slope |
|---|---|---|---|---|
| |
All Defaults |
|
11.2 |
2.0 |
|
Fixation Jitter: |
None |
Jittered |
11.0 |
2.0 |
|
RGC Parameters: |
|
|
|
|
| Spatial organization |
Regular |
Jittered |
10.9 |
2.0 |
| Spacing |
0.16° |
0.14° | 6.7 | 2.2 |
| 0.18° |
18.2 |
1.7 |
||
| Total number of cells |
150000 |
100000 | 10.5 | 1.8 |
| 200000 |
11.6 |
2.0 |
||
| Receptive Field Height |
Center 115 | 1.5 × default | 22.1 | 2.0 |
| Surround −2 |
0.5 × default |
7.4 |
2.0 |
|
| Maximum Driven Firing Rate |
65 ips |
40 ips | 17.9 | 1.4 |
| 100 ips |
9.0 |
2.4 |
||
| Baseline Firing Rate |
10 ips |
5 ips | 10.1 | 2.1 |
| 15 ips |
12.3 |
2.0 |
||
| Absolute Refractory Period |
1.5 ms |
1 ms | 7.9 | 1.6 |
| 2 ms |
13.9 |
2.1 |
||
| Relative Refractory Period |
2.0 ms |
1.5 ms | 3.8 | 0.6 |
| 2.5 ms |
15.5 |
2.2 |
||
|
Cortical parameters: |
|
|
|
|
| Retino:Cortico-EPSP Ratio |
2:1 |
1:1 | 58.0 | 1.1 |
| 4:1 |
4.5 |
2.2 |
||
| EPSP rise time |
2.9 ms |
2 ms | 24.0 | 2.4 |
| 3.5 ms |
3.8 |
0.6 |
||
| Filter Spatial Frequency |
0.5 cycles/° |
0.4 cycles/° | 9.3 | 2.0 |
| 0.6 cycles/° |
15.1 |
1.8 |
||
| Baseline Firing Rate |
5.6 ips |
3 ips | 8.4 | 2.2 |
| 8 ips |
12.6 |
1.5 |
||
| Attention Window |
60 ms |
30 ms | 16.0 | 1.5 |
| 120 ms |
9.1 |
2.1 |
||
| Decision Variable: nth largest signal | n=1 | n=4 | 16.0 | 3.0 |
| n=8 | 29.0 | 3.4 |