Table 1.

The pharmacology of precision. Please see [92] for details.

Neurotransmitter system	Functional role	Neuroanatomy
Cholinergic	Encoding the precision of outcomes given hidden states: (c.f., Attention and expected uncertainty [218, 219])	Nucleus basalis of Meynert
Noradrenergic	Encoding the precision of state transitions (c.f., Volatility and unexpected uncertainty [220])	Locus coeruleus
Dopaminergic	Encoding the precision of beliefs about policies (c.f. Action selection [221])	Substantia nigra pars compacta, Ventral tegmental area