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Sunday, January 02, 2011

Wisdom—A Neuroscience Perspective

http://innerhealingsandassociates.com/images/wisdom.gif

In a recent issue of JAMA, they published a commentary on the neuroscience of wisdom by Dilip V. Jeste, MD and James C. Harris, MD. Access to the article is a subscription (or media/press, which is me) only, so I can't post the whole thing here or I'll lose my access. But it's interesting, so I want to post a summary.

Full Citation:
Jeste, D.V. & Harris, J.C. (2010). Wisdom: A neuroscience perspective.
JAMA; 304(14):1602-1603. doi: 10.1001/jama.2010.1458

This is what they offered as the abstract:

Wisdom—A Neuroscience Perspective

  1. Dilip V. Jeste, MD;
  2. James C. Harris, MD
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. 1 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 2, 3, 4 have proposed definitions of wisdom that share several common elements.
Among the shared elements they mention in defining wisdom are the following:
  • 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
  • tolerance of divergent value systems (Meeks & Jeste, 2009)
When the authors examine the similarity of wisdom values in Greek philosophy, Hindu philosophy (The Bhagavad Gita, which predates Greek traditions), and Chinese Taoism, among other cultures, they propose that there may be an underlying biological substrate that manifests in these cultural values structures. They have looked at this topic in the past (Meeks & Jeste, 2009).

As you read the following summary, please keep in mind this morning's first post from Tyler Burge on neurobabble - anytime we reduce complex behaviors, especially culture-level behaviors and values, to images in the brain, we risk silliness at best.

That said . . .

The authors looked at the available neuroimaging studies and found that all of the basic wisdom values are found in two regions of the brain:
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 self-preservation), 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).
In light of these findings, I would add some more recent findings that have come out since this was published - Bickart, et all (2010), have found that a larger amygdala in humans is associated with larger social networks (this confirms earlier research in lower primates). The link was found to be specific to the amygdala because social network size and complexity were not found in any other subcortical structures, nor any other brain structures.

I mention this finding here because (1) the amygdala is a very old brain structure, likely preceding human culture, so that it's role in wisdom is suggestive of a possible evolutionary tendency, which becomes even more interesting in light of its connection to social networks, and (2) because the amygdala is also associated with fear and the fight/flight/freeze mechanisms that we see in PTSD. This poses interesting questions - in PTSD in the amygdala becomes enlarged through constant stress hormone (cortisol) exposure, but these people do not become more social, rather they tend to isolate and feel isolated.

I don't have any answers for these speculations - but it certainly bears continued research into the role of the amygdala in various interpersonal functions. [In their extended discussion of their findings, Bickert's team look at findings in autism and that some data suggests reduced amygdala size. They also discuss the data of how the amygdala plays "a particularly important role in processing of identity, trustworthiness, and all visual signals that involve some degree of uncertainty, ambiguity, or novelty."]

Anyway, back to the main study.

The structures identified above are all
components of the medial paralimbic circuitry. , are thought to bind together and underlie conscious subjective self-reference, which is essential to wisdom. Lou, et al (2010), suggest that these regions bind together and "underlie conscious subjective self-reference, which is essential to wisdom." This idea echoes the work of Antonio Damasio (2010) in his proposal that the brain stem and limbic system are essential to human self-awareness and self-perception (watch a video of Damasio talking about his ideas).

Echoing the classic psychology case of Phineas Gage, who suffered a steel rod through his frontal load in an accident and subsequently became a different man in terms of personality, the authors look at frontal lobe dysfunctions as an indicator of this brain region's role in social and wisdom behaviors:
Patients with tumors in this brain region also show similar effects on social judgment; however, frontotemporal dementia, which involves brain atrophy restricted to portions of the prefrontal and temporal lobes, offers a more striking example of wisdom-related neuropathology.8 Patients with frontotemporal dementia demonstrate dramatic changes in personality and become impulsive, socially inappropriate, and emotionally inept, with behaviors that are the antithesis of wisdom.
These findings lead them to assert that wisdom is not an on/off behavior, but rather a continuum ("there are different degrees of wisdom (or its opposite, foolishness) among individuals"). What is needed, they contend, are some good measures of wisdom, some form of reliable measurement which meets the psychometric standards of sensitivity, specificity, reliability, and validity. Most of the existing research uses self-rating scales or solving moral dilemmas in response to hypothetical vignettes (which may or may not address elements of wisdom).

Finally, the authors speculate on the relationship between age and wisdom. In many cultures, the elders are recognized as the wise members of the group (although, so far, empirical studies have been mixed). However, Grossman, et al (2010), found that despite some decline in cognitive functions as we age, "older adults demonstrated greater social reasoning—an essential component of wisdom." It's possible that age-associated wisdom offers some form of "evolutionary advantage to humans," some speculate, but I would be more inclined to look at its role in social cohesion and group bonding - "wise elders" are often arbitrators in conflict. There may be an evolutionary survival aspect to this, but it is likely secondary to immediate social function and cohesion.

The article concludes with the following speculations:
Emerging evidence suggests that it may be possible to promote the wisdom of aging and benefit the rest of the society simultaneously through community-based intergenerational programs, such as those in which older adult volunteers mentor school children.10 Future studies of wisdom should include an empirical evaluation of the possible effects of wisdom on personal well-being as well as societal good. Developing biological means to enhance the elements of brain functioning that are critical to wisdom may be years away but is potentially achievable. If damage to specific areas of the brain can lead to impairment in wisdom, stimulation of those regions, through behavioral, environmental, or biological approaches, may facilitate its recovery. The question is how scientists and society can accomplish such a task in an effective, safe, and ethical manner.
Despite these proposals, the authors also contend (and here I agree) that wisdom is an "emergent property of integrated brain functioning" and that no matter how much more we can learn from neuroscience, we are not likely to fully identify the elements that make humans wise.


References (in order):

Meeks
TW
& Jeste DV. (2009). Neurobiology of wisdom: a literature overview. Arch Gen Psychiatry;66(4):355–365, pmid:19349305. (Free full text)

Bickart, KC, Wright, CI, Dautoff, RJ, Dickerson, BC & Barrett, LF. (2010, Dec. 26). Amygdala volume and social network size in humans. Nature Neuroscience; DOI: 10.1038/nn.2724 (Free full text)

Lou, HC, Gross, J, Biermann-Ruben, K, Kjaer, TW & Schnitzler, A. (2010). Coherence in consciousness: paralimbic gamma synchrony of self-reference links conscious experiences. Human Brain Mapping;31(2):185–192, pmid:19621368. Medline; Web of Science

Damasio, A. (2010). Self Comes to Mind: Constructing the Conscious Brain. NY: Pantheon.

Grossmann, I., Na, J., Varnum, ME., Park, DC., Kitayama, S. & Nisbett, RE. (2010). Reasoning about social conflicts improves into old age. Proceedings of the National Academy of Science, USA;107(16):7246–7250, pmid:20368436. (Free full text)


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