Editing Caudate nucleus (section)

===Goal-directed action===
A review of neuroimaging studies, anatomical studies of caudate connectivity, and behavioral studies reveals a role for the caudate in executive functioning. A study of Parkinson's patients (see below) may also contribute to a growing body of evidence.

A two-pronged approach of neuroimaging (including [[positron emission tomography|PET]] and [[fMRI]]) and anatomical studies expose a strong relationship between the caudate and cortical areas associated with executive functioning: "non-invasive measures of anatomical and functional connectivity in humans demonstrate a clear link between the caudate and executive frontal areas."<ref name="Grahn 2009 146"/>

Meanwhile, behavioral studies provide another layer to the argument: recent studies suggest that the caudate is fundamental to goal-directed action, that is, "the selection of behavior based on the changing values of goals and a knowledge of which actions lead to what outcomes."<ref name="Grahn 2009 146"/> One such study presented rats with levers that triggered the release of a cinnamon flavored solution. After the rats learned to press the lever, the researchers changed the value of the outcome (the rats were taught to dislike the flavor either by being given too much of the flavor, or by making the rats ill after drinking the solution) and the effects were observed. Normal rats pressed the lever less frequently, while rats with lesions in the caudate did not suppress the behavior as effectively. In this way, the study demonstrates the link between the caudate and goal-directed behavior; rats with damaged caudate nuclei had difficulty assessing the changing value of the outcome.<ref name="Grahn 2009 146"/> In a 2003-human behavioral study, a similar process was repeated, but the decision this time was whether or not to trust another person when money was at stake.<ref>{{cite journal | vauthors = Elliott R, Newman JL, Longe OA, Deakin JF | title = Differential response patterns in the striatum and orbitofrontal cortex to financial reward in humans: a parametric functional magnetic resonance imaging study | journal = The Journal of Neuroscience | volume = 23 | issue = 1 | pages = 303–7 | date = January 2003 | pmid = 12514228 | pmc = 6742125 | doi = 10.1523/JNEUROSCI.23-01-00303.2003 }}</ref> While here the choice was far more complex––the subjects were not simply asked to press a lever, but had to weigh a host of different factors––at the crux of the study was still behavioral selection based on changing values of outcomes.

In short, neuroimagery and anatomical studies support the assertion that the caudate plays a role in executive functioning, while behavioral studies deepen our understanding of the ways in which the caudate guides some of our decision-making processes.