Wisdom--a neuroscience perspective.

PHILOSOPHERS, POETS, AND PUNDITS HAVE LONG PONdered human nature, positing psychological constructs such as consciousness, cognition, emotion, and resilience to stress. However, biological scientists have tended to ignore or avoid serious discussion and investigation of such constructs, considering them complex, or imprecise, and not measureable using conventional scientific methods. Recent research has shown that these constructs are scientifically valid and, importantly, that they rest on underlying biological foundations. However, one construct continues to be resisted by many in the neuroscience community—the construct of wisdom. Frequently dismissed as an ideal, amorphous, and convenient label for desirable traits that vary widely from one culture to another, wisdom has not been considered a topic suitable for scientific scrutiny. Yet there are surprising similarities among concepts of wisdom across cultural, geographic, and temporal boundaries. During the past 40 years, gerontologists, psychologists, and sociologists have proposed definitions of wisdom that share several common elements. These include rational decision making based on general knowledge of life; prosocial behaviors involving empathy, compassion, and altruism; emotional stability; insight or self-reflection; decisiveness in the face of uncertainty; and tolerance of divergent value systems. Wisdom is a complex human trait that can be viewed as being composed of the above-mentioned domains. Modern western definitions of wisdom are based on ancient Greek philosophy. Many of these defined elements of wisdom are also found in eastern philosophies—for example, in the Bhagavad Gita, a distillation of ancient Hindu philosophy that predates the earliest Greek philosophers by hundreds of years and in Chinese philosophies such as Taoism. The remarkable similarity in the descriptions of wisdom over the centuries and around the world suggests that there may be an underlying biological substrate that influences and is influenced by the life experiences and choices that make humans wise. A recent review of the literature summarized functional neuroimaging studies relevant to each of the subcomponents of wisdom mentioned above. Two brain regions were identified as being common to different domains of wisdom— the prefrontal cortex (especially dorsolateral, ventromedial, and anterior cingulate) and the limbic striatum. These areas are phylogenetically the newest and the oldest parts of the brain. Wisdom seems to require the brain to carefully match and integrate the activities of these areas: the dorsolateral prefrontal cortex (involved in the rational, disciplined, and calculated actions necessary for selfpreservation), ventromedial prefrontal cortex (involved in kind, supportive, social, and emotional behavior needed for survival of species), the anterior cingulate (detecting and mediating when the 2 parts of the prefrontal cortex are in conflict), and limbic striatum with amygdala (the reward circuitry). These brain regions, intrinsic components of medial paralimbic circuitry, are thought to bind together and underlie conscious subjective self-reference, which is essential to wisdom. Wisdom also may be approached in neuroscience by considering the effects of localized damage on these brain regions that appear to be critically involved in the construct of wisdom. Damage to these regions of the brain, especially the prefrontal cortex, either through trauma or degeneration, can result in a loss of subjective features associated with wisdom. For example, Cato et al described the case of a “modern-day Phineas Gage. ” A 26year-old man with an exemplary academic and professional record had a penetrating head injury that caused bilateral ventromedial prefrontal damage, more so on the left side. The trauma resulted in a precipitous decline in his social and behavioral functioning. Like the 19th-century Gage, this patient lost his job despite average to superior scores on most neurocognitive tests (eg, verbal IQ of 119), and subsequently had a lifelong history of temporary lowlevel jobs. Although he married, there were several marital break-ups with estrangement from his children.