Role of the Orbitofrontal Cortex in the Computation of Relationship Value

This research investigated whether the medial orbitofrontal cortex (OFC), which is known to code the value of various rewards, is involved in the relationship value recalibration process. Previous research suggests that people upregulate the relationship value of a specific friend in response to the friend's commitment signals. In a functional magnetic resonance imaging study (Study 1), participants imagined receiving high-cost commitment signals, low-cost commitment signals, or no signals from a particular friend. Participants' subjective rating of the relationship value upregulation was positively correlated with medial OFC activity. Subtraction analyses showed that high-cost commitment signals engaged the medial OFC more than did signal failures. An auxiliary analysis revealed that medial OFC activity in response to low-cost commitment signals was negatively correlated with loneliness. To follow-up these findings, we conducted an online vignette study (Study 2), in which participants rated the relationship value of a real friend before and after imagining receiving a series of low-cost commitment signals from that friend. Corroborating the upregulation hypothesis, perceived relationship value significantly increased after imagining a series of commitment signals. This effect was weaker among individuals high in loneliness.