Mechanisms of long term non-externally reinforced preference change: functional connectivity changes in a longitudinal functional MRI study

Behavioral change studies mostly focus on external reinforcements to modify preferences. Cue-approach training (CAT) is a paradigm that influences preferences by the mere association of stimuli, sensory cues, and a rapid motor response, without external reinforcements. The behavioral effect has been shown to last for months after less than one hour of training. Here, we used a modified version of CAT by changing the neutral-cue to a number that represented a monetary amount of reward that the participants accumulate (i.e. incentive-cue). After a single training session, we compared behavioral performance and functional connectivity (FC), as measured by resting-state scans using functional magnetic resonance imaging, between two groups (total of 107 males and females in both groups), one receiving a neutral-cue and the other receiving an incentive-cue, at 5 time points across one year. We replicated the maintenance of behavioral changes after 6-months for the non-externally reinforced neutral-cue participants, but not for the reinforced group. The reinforced training group showed higher FC within the limbic system, whereas the non-externally reinforced group showed higher functional connectivity within and between default-mode and dorsal-attention networks. Our findings offer putative neural correlates for both reinforced and non-externally reinforced preference changes that are maintained over time and which could be implemented in future behavioral change interventions. Significance Statement The current work examines the neural mechanisms of non-externally reinforced preference change and its maintenance over time, using both a neutral cue and a modified version of the cue-approach training paradigm. While both groups initially exhibited preference shifts, only the non-externally reinforced group maintained preference changes over one year, suggesting an enduring internal reinforcement mechanism. We identified distinct patterns in functional connectivity related to behavioral maintenance. We found that non-external reinforcement increases the connectivity of the default mode network while external reinforcement elevates connectivity between limbic areas. These findings enhance our understanding of sustainable behavior change and advocate for non-external reinforcement in behavioral interventions.