Imaging Happiness: Meta Analysis and Review

A challenge in studying happiness is its conceptual nature. Is the happiness of hedonistic indulgence the same as the happiness of selfless volunteering? To understand some of these questions, a narrative review of 64 neuroimaging studies between 1995 and 2018 was conducted. Studies were grouped based on how they conceptualized happiness based on Seligman’s (Authentic happiness: using the new positive psychology to realize your potential for lasting fulfillment, Simon and Schuster, New York, 2002) authentic happiness theory. A qualitative narrative review was performed as well as an ALE meta analysis of activation regions. Happiness was identified in 33 separate brain regions across the telencephalon, diencephalon, and metencephalon. Stratifying results by definition of happiness, regions of activity were generally relevant to the tasks performed during the experiment and the kinds of tasks enjoyed by the phenomenon of happiness examined. The ALE analysis identified the claustrum, insula, basal ganglia, and thalamus as showing meaningful activation clusters across studies. Happiness as pleasure and engagement demonstrated close relevance of neural activity to literal activities being performed. Tasks for happiness as meaning, on the other hand, were generally more abstract. Likewise, there was less direct relationship between behavior and phenomenon of happiness, the insula most likely to activate for happiness as meaning. It was concluded that happiness is not best understood as an affective state, but better understood within its behavioral context, as an emergent property of activity. For pleasure and engagement, this meant a literal relationship between behavioral and neurological activity. For meaning, this meant the ongoing assessment of the moral implications of events. Limitations included cross sectional design and hemodynamic focus. Future research should consider concordance of happiness and brain activity across the lifespan. Additionally, future studies should consider the dynamics of neuropeptides.