Table 4.
Reinforcement model parameters: model used for fMRI analyses
| Mean | (SEM) | ||
|---|---|---|---|
| Learning rate (α)a | IMMED (1s) | 0.22 | (0.06) |
| DELAY (4s) | 0.49 | (0.09) | |
| DELAY (7s) | 0.34 | (0.08) | |
| Across conditions | 0.35 | (0.06) | |
| Softmax inverse temperature (β) | Across conditions | 5.10 | (1.39) |
| Pseudo-r2 | 0.27 | (0.04) | |
| Model fit (log likelihood) | 93.22 | (4.68) | |
| Chance model fit | 124.77 | ||
| Likelihood ratio test (model vs chance) | p < 0.0001 | ||
| Softmax inverse temperature (β) (α fixed to 1) | 0.77 | (0.07) | |
| Model fit (α fixed to 1) | 106.89 | (2.80) |
aLearning rates did not differ as a function of delay (linear effect: F(1,19) = 2.40, p = 0.14).