An important feature of the model is that varying the systems
weighting parameter v (while sharing the other parameter values
of the model across subgroups) is sufficient to qualitatively
reproduce the characteristics of the different subgroups of rats
observed experimentally during these studies.
To improve the matching of the following results with the main
experimental data, a different set of parameter values was used for
each subgroup (ST, GT and IG). The values were retrieved after
fitting autoshaping data only (see Methods, Table S1). Simulated
results on other behavioural, physiological and pharmacological
data are generated with the same parameter values. While it might
result in a weaker fitting of the other experimental data, this
permits a straightforward comparison of results at different levels
for the same simulation. Moreover, it confirms that the model can
reproduce behavioural, physiological and pharmacological results
with a single simulation per subgroup.