Table 1.
Parameters in Experiment 3. Shown in bold is the information conveyed by the CS in each set of conditions.
| Fixed Duration CS | Variable Duration CS | |||
|---|---|---|---|---|
| CS Dist | fixed @ 20 s | CS Dist | gamma(4,5) | |
| E(CS dur) | 20 | E(CS dur) | 20 | |
| ITI Dist | gamma(3,46.67) | ITI Dist | gamma(3,46.67) | |
| E(ITI dur) | 140 | E(ITI dur) | 140 | |
| E(US-US) | 160 | E(US-US) | 160 | |
| Small C̅/T̅ | C̅/T̅ | 8 | C̅/T̅ | 8 |
| Pellets/Hr | 22.5 | Pellets/Hr | 22.5 | |
| SessDur | 3.5 hrs | SessDur | 3.5 hrs | |
| Hcs-us | 6.95 bits* | Hcs-us | 8.56 bits† | |
| Hus-us | 11.56 bits† | Hus-us | 11.56 bits† | |
| ΔH | 4.6 bits | ΔH | 3 bits | |
| CS Dist | fixed @ 20 | CS Dist | gamma(4,5) | |
| E(CS dur) | 20 | E(CS dur) | 20 | |
| ITI Dist | gamma(3,156) | ITI Dist | gamma(3,156) | |
| E(ITI dur) | 468 | E(ITI dur) | 468 | |
| Large C̅/T̅ | E(US-US) | 488 | E(US-US) | 488 |
| C̅/T̅ | 24.4 | C̅/T̅ | 24.4 | |
| Pellets/Hr | 7.4 | Pellets/Hr | 7.4 | |
| SessDur | 10.6 hrs | SessDur | 10.6 hrs | |
| Hcs-us | 6.95 bits* | Hcs-us | 8.56 bits* | |
| Hus-us | 13.16 bits† | Hus-us | 13.16 bits† | |
| ΔH | 6.2 bits | ΔH | 4.6 bits | |
Assuming a cv of .16 and temporal resolution of .1 s
Assuming temporal resolution of .1 s
Note. E(CS dur) is the expected duration of the CS (aka T̅). E(ITI dur) is the expected duration of the intertrial interval. E(US-US) is the expected duration of the US-US interval (aka C̅). Hcs-us is the entropy of the distribution of CS durations. When CS duration is fixed, it is assumed to have the entropy of a gauss(20,3) distribution. When CS duration varies, the entropy is taken to be the entropy of the gamma(4,5) distribution of CS durations. Hus-us is the entropy of the distribution of US-US intervals. ΔH is Hus-us - Hcs-us, which is the Shannon information communicated to the subject by the onset of the CS. Entropy calculations were done numerically, assuming a temporal resolution of 0.1 s. (The resolution assumed has no effect on the entropy differences, provided it is small relative to the width of the distributions.) The increase in C̅/T̅ from the Small to Large conditions increases ΔH by 1.6 bits. The difference in information communicated by CS onset between the fixed and variable conditions (the difference in the ΔH 's between columns within rows) is also 1.6 bits.