The ability to learn new tasks rapidly is a prominent characteristic of human behaviour. This
ability relies on flexible cognitive systems that adapt in order to encode temporary programs for
processing non-automated tasks. Previous functional imaging studies have revealed distinct
roles for the lateral frontal cortices (LFCs) and the ventral striatum in intentional learning
processes. However, the human LFCs are complex; they house multiple distinct sub-regions,
each of which co-activates with a different functional network. It remains unclear how these LFC
networks differ in their functions and how they coordinate with each other, and the ventral
striatum, to support intentional learning. Here, we apply a suite of fMRI connectivity methods to
determine how LFC networks activate and interact at different stages of two novel tasks, in
which arbitrary stimulus-response rules are learnt either from explicit instruction or by trialand-error.
We report that the networks activate en masse and in synchrony when novel rules are
being learnt from instruction. However, these networks are not homogeneous in their functions;
instead, the directed connectivities between them vary asymmetrically across the learning
timecourse and they disengage from the task sequentially along a rostro-caudal axis.
Furthermore, when negative feedback indicates the need to switch to alternative stimulusresponse
rules, there is additional input to the LFC networks from the ventral striatum. These
results support the hypotheses that LFC networks interact as a hierarchical system during
intentional learning and that signals from the ventral striatum have a driving influence on this
system when the internal program for processing the task is updated.