Cortico-striatal white-matter connectivity underlies the ability to
exert goal-directed control
Abstract
The balance between goal-directed and habitual control has been proposed
to determine the flexibility of instrumental behavior, in both humans
and animals. This view is supported by neuroscientific studies that have
implicated dissociable neural pathways in the ability to flexibly adjust
behavior when outcome values change. A previous Diffusion Tensor Imaging
study provided preliminary evidence that flexible instrumental
performance depends on the strength of parallel corticostriatal
white-matter pathways previously implicated in goal-directed and
habitual control. Specifically, estimated white-matter strength between
caudate and ventromedial prefrontal cortex correlated positively with
behavioral flexibility, and posterior putamen – premotor cortex
connectivity correlated negatively, in line with the notion that these
pathways compete for control. However, the sample size of the original
study was limited and so far, there have been no attempts to replicate
these findings. In the present study, we aimed to conceptually replicate
these findings by testing a large sample of 205 young, healthy adults to
relate cortico-striatal connectivity to performance on the
slips-of-action task. In short, we found only positive neural correlates
of goal-directed performance, including striatal connectivity (caudate
and anterior putamen) with the dorsolateral prefrontal cortex. However,
we failed to provide converging evidence for the existence of a neural
habit system that puts limits on the capacity for flexible,
goal-directed action. We discuss the implications of our findings for
dual-process theories of instrumental action.