Brain imaging can predict behavior days in advance.

Falk et al. find a brain region that seems to make a more reliable report of people's intentions than their self-reported attitudes and intentions. (It does seems a bit spooky when a machine reports what we are going to do more accurately than we can.)  The medial prefrontal regions which were predictive of behavior are ones I've mentioned in a previous post that predict spontaneous motor behavior several seconds before reportable motor intentions form.  The authors measured neural activity while people were exposed to persuasive messages regarding the value of regular sunscreen use, and then used those values to predict future behavior change in the same individuals (i.e., increased sunscreen use. Successful persuasion-induced behavior change had been observed in this domain in several previous studies.)  The relevant medial prefrontal regions:

..are reliably coactivated across a host of "self" processes.....[and]  have been previously observed in multiple studies of persuasion and attitude change.. .indicating that these regions may be involved in the formation of behavioral intentions that are not accessible to conscious self-report.

Here is a figure and their abstract:

Regions associated with behavior change in a whole brain analysis. These regions have been observed as predictors of spontaneous motor behavior, before and independent of consciously reportable behavioral intentions.

Although persuasive messages often alter people's self-reported attitudes and intentions to perform behaviors, these self-reports do not necessarily predict behavior change. We demonstrate that neural responses to persuasive messages can predict variability in behavior change in the subsequent week. Specifically...a ..region of interest..in medial prefrontal cortex .. was reliably associated with behavior change...activity in this region predicted an average 23% of the variance in behavior change beyond the variance predicted by self-reported attitudes and intentions. Thus, neural signals can predict behavioral changes that are not predicted from self-reported attitudes and intentions alone. Additionally, this is the first functional magnetic resonance imaging study to demonstrate that a neural signal can predict complex real world behavior days in advance.