Table 2.
Information measures for samples of PC afferents stimulated with Gaussian noise at 2 different bandwidths. Means and standard deviations (in parentheses) are given for each measure. Mean value of cv* for the sample was 0.56 (0.15). Lower bound estimates, ILB, are calculated from SR coherence functions; upper bound estimates, IUB, from RR coherence functions. Both are given in bits/s as well as bits/spike. All information measures except the PI index and the coding fraction clearly increased as stimulus bandwidth increased, indicating that afferents are encoding the higher frequencies. At both 10 Hz and 50 Hz, 60–70% of the information in the spike train was linearly encoded. ILB; lower bound estimates.
| Freq. | N | ILB, bits/s | ILB, bits/spike |
IUB, bits/s | IUB, bits/spike |
PI index | Coding fraction |
|---|---|---|---|---|---|---|---|
| 10 Hz | 10 | 7.14 (3.55) | 0.63 (0.33) | 11.01 (5.18) | 1.00 (0.57) | 0.69 (0.15) | 0.25 (0.11) |
| 50 Hz | 10 | 16.9 (12.1) | 1.17 (0.53) | 30.01 (21.78) | 2.17 (1.39) | 0.64 (0.18) | 0.11 (0.06) |