Embracing the Unknown

Researchers are showing that ambiguity can be essential to brain development.

By Jamie Holmes | November 1, 2015

CROWN, OCTOBER 2015Scholars have sliced and diced the terms “ambiguity,” “uncertainty,” and “ignorance,” among others, in a variety of different ways. Oftentimes, the usefulness of these sharp lines isn’t plainly apparent. But one dividing line between types of unknowns that has recently led researchers to fascinating new biological insights is the distinction between risk and ambiguity. According to decision theorists, risky choices are those where the specific outcome isn’t known while the odds of success are. Think of flipping a coin. You’re certain of the probability of its landing on heads or tails, but you can’t predict the outcome of any particular toss. Ambiguous choices are those whose odds of success are unknown because the rules determining the outcome are unclear.

This important distinction between ambiguity and risk is one that I explore in my book, Nonsense: The Power of Not Knowing.

Economic theorist Daniel Ellsberg’s famous thought experiment illustrates the contrast. Say you have to pick out a ball from one of two urns, both containing black and red balls. Each urn contains one hundred balls. Pull out a red ball, and you’ll win a hundred dollars. Pick a black one, and you’ll get zilch. But the two urns are different. Urn 1 holds anywhere from zero to one hundred red balls and from zero to one hundred black ones. Urn 2 has fifty black balls and fifty red balls. Ellsberg realized that if you ask people whether they’d prefer to bet on pulling from Urn 1 or Urn 2, most people will choose Urn 2. The participant has no information as to whether Urn 2 offers better or worse odds than Urn 1, and yet the majority of people prefer drawing from the known mix of balls. That’s ambiguity aversion.

Evidence from brain science has shown that the amygdala and the orbitofrontal cortex are more active when people face ambiguous odds rather than merely risky ones, suggesting that ambiguity is fundamentally more emotional. This premise held when participants in a study led by the University of California, Berkeley’s Ming Hsu (then a graduate student at Caltech) were asked to wager on either the high temperature in New York (involving known probabilities) or the high temperature in Tajikistan (involving unknown ones) on a given day. Even when precise odds exist, if they are unknown—as they often are in everyday decision making—then we treat the decision as ambiguous.

A 2010 study that replicated a variation of Ellsberg’s urn experiment (using juice) with rhesus macaques showed that our preference for clear odds may have deep evolutionary roots. Led by University of Rochester cognitive scientist Benjamin Hayden, then a postdoc in Michael Platt’s lab at Duke University, researchers found that monkeys also prefer known odds over unclear probabilities, even when that preference isn’t rational. This phenomenon holds for chimpanzees and bonobos, too.

Yale neuroscientist Ifat Levy and other researchers, including the University of Sydney decision scientist Agnieszka Tymula (then at New York University), published a study in 2012 suggesting that adolescents, despite their often wild behavior, are actually less risk-tolerant than adults. An adolescent tolerance of ambiguity, they found, is what compels teens to test the unknown. “There is no real biological advantage for adolescents to be risk-seeking,” Tymula says. “The advantage comes with ambiguity tolerance.” Rather than seeing uninhibited behavior as the product of underdeveloped brains, her research suggests that teens are programed to explore what they don’t yet understand. Tymula has found that risk tolerance and ambiguity tolerance follow different pathways across the human life span, and that they are even affected uniquely by weather: ambiguity is more bearable after the sun comes out.

Rather than portraying the unclear as solely negative, researchers are instead revealing ambiguity to be a powerful cognitive force that can drive our brains in fruitful directions. Recognizing ambiguity, it turns out, motivates creativity and exploration. 

Jamie Holmes is a Future Tense Fellow at New America and a former research coordinator at Harvard University in the Department of Economics.

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Avatar of: Rachel Francon

Rachel Francon

Posts: 3

November 30, 2015


An interesting article..However the subtitle "the Power of Not Knowing" is rather unfortunate in the light of much of the neuroscience of our current day and age.

 I would just have loved to have seen some actual discussion of the likely neuroscience involved in the capacity of some to tolerate ambiguity and to undertake risks.   

As to what these authors of the book in question do not seem to mention is a  landmark book by McClelland back in the 50s where he defined for our society the notion of "Achievement Motivation"  What always struck me and stuck with me from that work was his interesting depiction of great "follies" in our cultural history to foreshadow how some people took 'risks" which to them "were not really risks" of the magnitude as assessed by the outside "objective" observer.

I recall him pointing to "Fulton's Folly" (the steam engine), Seward’s Folly (the purchase of Alaska) the Wright Brothers and Henry Ford.  These folks may have been 'young at heart and at mind" but they were not simply adolescents growing up who then were able to tolerate some otherwise self evident ambiguous and highly risk situation into which they threw themselves.  Today, Steve Jobs, would qualify as another one who "knew differently, although he liked to say "Think Different"

The book in question might have been more in tune with neuroscience and a source of more light rather than more ambiguity if the concept they promoted and expressed here treated more fully and hence were"

"The Power of Knowing Differently"

No, "the Power of NOT Knowing"  was  most emphatically not what McClelland had to say about that topic.  For him these persons who clearly confounded the external observer were operating on the basis of "other knowledge" to which the external observer had no access. They realized the ambiguity and risk but also know from their own experiences that they had the potential wherewithal to muster up responses to those elements which others considered on the face of it to be insurmountable risks.

To me, nowadays this smacks of some very interesting access to episodic memory and the function of their hippocampal system as the link between the amygdala and the various cortical centers of cognition.  These folks did not have a grant proposal or step by step declarative concept of their plans...although it might have been potentially possible to engage them in discourse for long enough...if they didn't think that silly...to articulate some of their "knowledge" of which they felt aware but could not express.

And surely, as McClelland back then was telling us the various "follies" were due to how and why these folks determined what was "salient" to them in terms of their past relating to the project being considered...and indeed, even being considered in the first place.

The role of being able to call up the adequate experience of a previous moment to deal with a current or future moment is what all the "noise" is about in our studies of functional connectivity and it is not surprising that the some of that and the pivotal aspect of that "decision" and the confidence in having known previous decisions did indeed occur and that these decisions had relevance to the current or future situation..is what makes us able to successfully bring to bear past 'moments' in current and future moments. That inability is a symptom of many neurologically characterized disorders and neurodegenerative states.

For some persons…and for most of us in a sanguine context…what seems like “ambiguity” may not be such at all, because the situation calls up a previous experience to which its paramaters and details are relevant and not the one that an outside observer might.

In real life, unlike the situation in the economist's study, where there is an illusion of the possibility of objective knowledge of the "facts' created by the contrived experiment in the lab,  those on the outside don't know the most important facts of all…but the person doing the deciding has access to those episodically based and re-callable facts of his own experience. 

What this feeling of access...a feeling of 'recognition" that a current situation is akin to an previous success ...gives us is a different level of "connectivity...and the salience network as it relates to the expectation of reward in cortical centers operates very differently when the episodic memory of first hand experience is brought to bear in harnessing the salience driven consequences.

This altered calculation of salience is, while different from “risk taking”, nonetheless often related to what seems to be ‘risk taking” to an outside observer but is not considered to be such a great risk to the person engaging in the activity. This is not only the product of “not knowing’ being a virtue or the tolerance of not knowing being that virtue.

It is much more the product of “knowing differently” what can be brought to bear to a situation to first configure it within a relevant domain of previous episodes in a person’s past and that also can give that person an awareness of just what assets and resources he may have to bring to bear in solving that problem.  So yes in can be seen to give him or her “confidence’ but it is more likely a novel arrangement of a network connectivity relating the limbic system via the salience network to actions/decision where the weighing of expectancy of rewards is altered.

There are indeed very likely further mechanisms of the manner in which the hippocampus and the cortex are structured very differently in the manner in which they allow us 'to act" (for that is after all the point of all that cortical embellishment on top of the ancient mammalian hippocampus)

Indeed as has been found increasingly in recent research such as the Mosers work on navigation in the most clearcut instance, there are elaborate loops between t he hippocampus cells and those in the entorhinal cortex (in that line of research) which go full circle between the two areas in order to achieve navigation in space.

As we navigate through life it is not too cavalier, I hope, to suggest that these complete loops of connection between the "episodic" so called "memories' of the hippocampus can, even after they are consolidated into cortical declaratively available form cannot still be accessed by some of us and indeed by most of us (under the right circumstances) as we guide ourselves through the maze of life in our society.

Surely that concordance of one episode seen in its relation...sometimes surprising and sometimes truly novel....is what kicks in the salience network.and the loop between the cortex and action that can be characterized as not at all being without basis...and for those lucky enough to "re-call" that experience in it vividness...not at all being characterized by THEM as not at all being without expectation of reward.

Suffice it to say that it was somewhat disappointing not to see this "other" and far more  provocative and interesting field of neuroscience brought to bear on "redefining the problem rather than adding just a bit more of ambiguity to the reader seeking to get a grasp of it.

Wittgenstein notably once said something like, "the solution to a problem is seldom an 'answer", but is the going away of the problem"

And perhaps the authors of the  book/article cited here might have redefined the problem just a bit so as not to merely expand the chronic ambiguity which incomplete neuroscience often conveys to the reader of its statements..

By venturing into neuroscience a bit more and thus not sticking to the age old, same old defining of "problems"..the authors might not have merely brought more of that fog of ambiguity within their well meaning statements meant to clear things up.

Most definitely, there is not much power in "Not Knowing" !!  It's a catchy line, but confuses the issue rather than clarifying it.

And this statement just leads us further into the fog of not understanding how remarkable things are often done...by these great people, and even by all of us each and every day .  For that is what we all do, when we "know" that something is the case and don't confine ourselves to the ever ready warnings made by those who think they know the facts and thus the salience network is reconfigured to allow us to differently bring to bear episodes from out past…and entirely different episodes at times

And as psychotherapy knows, when you establish the confluence of two such streams of episodically based structures in the hippocampal area, you not only have a pleasant feeling of surprise that previous episode in your past may now be quite relevant to an ostensibly (to the outside observer) unrelated currently immanent situation, but that, as well, the expectancy of reward may immediately jump as the previous successful episode comes to flow into and merge with the current situation which demands to be addressed.

Those on the outside don't know the most important facts of all…or perhaps they only know when they have stacked the balls in a box.  In real life, the tables are turned on the experimenters and their illusion of knowing what the person doesn't know is replaced precisely by not knowing what the person they observe knows.

The most important facts that only we know are those episodes in our past whose vividness and detail can allow us to relate THEM as more salient than the words of those in the outside world.

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