The genetics of neuroticism and human values

Neural coding of human values is underpinned by brain areas representing the core self in the cortical midline region

The impact of human values on our choices depends on their nature. Self-Transcendence values motivate us to act for the benefit of others and care for the environment. Self-Enhancement values motivate us to act for our benefit. The present study examines differences in the neural processes underlying these two value domains. Extending our previous research, we used fMRI to explore first of all neural correlates of Self-Transcendence vs Self-Enhancement values, with a particular focus on the putative role of the medial prefrontal cortex (MPFC), which has been linked to a self-transcendent mind-set. Additionally, we investigated the neural basis of Openness to Change vs Conservation values. We asked participants to reflect on and rate values as guiding principles in their lives while undergoing fMRI. Mental processing of Self-Transcendence values was associated with higher brain activity in the dorsomedial (BA9, BA8) and ventromedial (BA10) prefrontal cortices, as compared to Self-Enhancement values. The former involved activation and the latter deactivation of those regions. We did not detect differences in brain activation between Openness to Change vs Conservation values. Self-Transcendence values thus shared brain regions with social processes that have previously been linked to a self-transcendent mind-set, and the "core self" representation.

Nonlinear associations between human values and neuroanatomy

Human values guide behavior and the smooth functioning of societies. Schwartz's circumplex model of values predicts a sinusoidal waveform in relations between ratings of the importance of diverse human value types (e.g., achievement, benevolence) and any variables psychologically relevant to them. In this neuroimaging study, we examined these nonlinear associations between values types and brain structure. In 85 participants, we found the predicted sinusoidal relationship between ratings of values types and two measures of white matter (WM), volume and myelin volume fraction, as well as for grey matter (GM) parameters in several frontal regions. These effects reveal new functional associations for structural brain parameters and provide a novel cross-validation of Schwartz's model. Moreover, the sinusoidal waveform test can be applied to other circumplex models in social, affective and cognitive neuroscience.

A Hedonism Hub in the Human Brain

Human values are abstract ideals that motivate behavior. The motivational nature of human values raises the possibility that they might be underpinned by brain structures that are particularly involved in motivated behavior and reward processing. We hypothesized that variation in subcortical hubs of the reward system and their main connecting pathway, the superolateral medial forebrain bundle (slMFB) is associated with individual value orientation. We conducted Pearson's correlation between the scores of 10 human values and the volumes of 14 subcortical structures and microstructural properties of the medial forebrain bundle in a sample of 87 participants, correcting for multiple comparisons (i.e.,190). We found a positive association between the value that people attach to hedonism and the volume of the left globus pallidus (GP).We then tested whether microstructural parameters (i.e., fractional anisotropy and myelin volume fraction) of the slMFB, which connects with the GP, are also associated to hedonism and found a significant, albeit in an uncorrected level, positive association between the myelin volume fraction within the left slMFB and hedonism scores. This is the first study to elucidate the relationship between the importance people attach to the human value of hedonism and structural variation in reward-related subcortical brain regions.