Table 2. Model fits. Mean ± SEM.
Model | -LLE | AIC | Pseudo-R2 | α | αApproach | αAvoid | β |
---|---|---|---|---|---|---|---|
Working memory | |||||||
Random choice | 240.76±22.860 | 240.767±45.720 | - | - | - | - | - |
Canonical | 182.068±23.126 | 186.068±46.252 | 0.291±0.028 | 0.152±0.024 | - | - | 0.286±0.043 |
Approach/avoidance | 174.586±22.641 | 180.586±45.282 | 0.320±0.029 | - | 0.282±0.045 | 0.077±0.019 | 0.258±0.027 |
Habitual | |||||||
Random choice | 79.467±0.581 | 79.467±1.162 | - | - | - | - | - |
Canonical | 55.801±2.398 | 59.801±4.796 | 0.297±0.030 | 0.223±0.056 | - | - | 0.229±0.037 |
Approach/avoidance | 51.384±2.696 | 57.384±5.392 | 0.354±0.036 | - | 0.175±0.043 | 0.221±0.054 | 0.161±0.032 |
LLE is the log-likelihood estimate. AIC is the Akaike Information Criterion. α denotes learning rates and β the trade-off between exploration and exploitation. Working memory and Habitual refer to two different learning systems which can be assessed by fitting model parameters to behavioural data during the training and testing phase, respectively [12].