SELF-EVALUATION: People's accuracy in assessing their own ability to have answered a question correctly might have a biological basis in a top-level brain center.
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When answering a question, your accuracy in assessing whether you have gotten the answer right—or wrong—might depend on the volume of gray matter in a certain part of your brain, according to a new study.
Introspection—or metacognition, self-awareness about one's thinking—is a high-level mental process. "Accurate introspection requires discriminating correct decisions from incorrect ones, a capacity that varies substantially across individuals," researchers behind the new findings explained in their study.
For the study, researchers used simple visual stimuli to test 32 healthy subjects' perception—and how confident they felt about their assessment of a geometric image. The tests were customized to each individual's level of perceptual skill, in order to keep each subject's accuracy score at 71 percent, so that the test was consistently difficult for all subjects.
"Someone who has good introspective ability will accurately be able to know" if they were correct in their assessment of an image, explains Steven Fleming, a cognitive neuroscientist at the Wellcome Trust Centre for Neuroimaging at University College London and co-author of the new study.
The study team found "considerable variation" in subjects' accuracy in assessing their own evaluations of the images, which was to be expected based on previous research. Fleming and his colleagues used magnetic resonance imaging (MRI) to evaluate the subjects' whole brains for differences in structure and composition in order to look for correlations with introspective ability.
Test subjects' accuracy in assessing their own performance "was significantly correlated with gray-matter volume" in the right anterior prefrontal cortex, the team wrote in their study report, published online September 16 in Science. Subjects with more accurate introspective assessments also tended to have denser connections between that area of gray matter and the axon-filled white matter that connected it.
"We were surprised that we could find differences in the structure in this region that were linked to something high-level like introspective ability," Fleming says.
The difference in gray-matter volume might help clarify the extent to which a person's confidence about his or her introspective abilities is supported. For instance, consider this scenario: Two people see the same scene but quickly come to very different conclusions about the details of what they saw—with both individuals stubbornly clinging to their own judgment even if only one is correct. A third witness might consider his or her own interpretation more deeply but still not be entirely sure that it is correct. Should we trust the most confident witness? Typically, we do. On a day-to-day basis, "we believe that judgments made with high confidence are more accurate," Hakwan Lau and Brian Maniscalco, both of the psychology department at Columbia University and not involved in the new research, wrote in a companion essay in the same issue of Science. "This correlation between confidence and accuracy, although often true, unfortunately is not infallible," they noted.
The new findings bear indirectly on this: An MRI might be able to predict the validity of a person's assessment of his or her own judgments by examining the volume of gray matter in this region. "If you scanned someone's brain, and they show very low gray-matter density in the prefrontal cortex, when they say they are very sure of something, you may not want to take their confidence too seriously," Lau notes.
The brain region tied to metacognition in this study is located behind the eyes; and even though the test itself was based on visual perception, Fleming points out that the anterior prefrontal cortex has been associated with top-level processing abilities that are thought to set humans apart from other animals. Nonhuman brains seem to be less developed in this region. Other researchers see the new finding as a way to investigate the metacognitive abilities of other than healthy adult subjects. "Other animals [and] children have less developed prefrontal cort[ices]," Lau says. "So we may want to test if they are less good in this kind of introspection task." Some animals in studies, he and Maniscalco pointed out in their essay, seemed to be more eager to opt out of tests in which they had low accuracy rates, "as if they were expressing 'uncertainty,'" having engaged in at least some introspection.
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12 Comments
Add CommentIt would be interesting to see the geometric images used.
Reply | Report Abuse | Link to thisIt would be interesting to see what geometric images were used.
Reply | Report Abuse | Link to thisThis article makes me think about the ill-contemplated Bering in Mind blog post back in July. What's scary is there were people who agreed with it.
Reply | Report Abuse | Link to thisHow could they possibly ensure equal accuracy in judging differences in geometric shapes amongst the participants? Even if they fine tuned it individually, getting the accuracy down to precisely "71 percent" seems a large stretch to me....
Reply | Report Abuse | Link to thisThea article quotes a companion essay written by members of
Reply | Report Abuse | Link to thisthe psychology department at Columbia University not involved in the new research:
"If you scanned someone's brain, and they show very low gray-matter density in the prefrontal cortex, when they say they are very sure of something, you may not want to take their confidence too seriously."
Based on the direction that Neurologists seem to be taking their brain imaging research, it's only a matter of time before governments, corporations, military and police interrogators, your boss, internet dating subscribers, et al, may be able to assess whose assessments, opinions, etc. based on some conveniently simple brain scanning technology. Your phone manufacturer should announce this capability soon. But, don't believe me: I'm just paranoid, as I'm sure you'll someday be able to confirm...
Back to the study, without paying an annual membership to the American Association for the Advancement of Science, dedicated to advancing the careers of scientists, I can't read the reports, but it seems as though the researcher had some expectation that the volume of identified gray matter in the prefrontal cortex would correlate to this ability. Otherwise, a statistical analysis of characteristic physical properties of varying regions of the brain would have been required to determine what physical brain characteristic is associated with this introspective/self-assessment capability. So, what led these researchers to identify this prefrontal cortex gray-matter as the locus of causation? I am suspicious of research that merely confirms preexisting expectations...
By the way, if no multivariate analysis of the introspective ability scores and other potential factors, the identified gray-matter correlation cannot be identified as a causal factor. Since these researchers were reportedly limiting their search for causation to a visual scan of distinguishing brain features, it cannot be determined, for example, that introspection is more highly correlated with the number of serotonin receptors o
Reply | Report Abuse | Link to this<replacing previous comment somehow inadvertently sent>
Reply | Report Abuse | Link to thisBy the way, if no multivariate analysis of the introspective ability scores and other potential factors was performed, the identified gray-matter correlation cannot be identified as a causal factor.
Since these researchers were reportedly limiting their search for causation to a visual scan of distinguishing brain features, it cannot be determined, for example, that introspection is more highly correlated with the number of serotonin receptors or the rate neuronal signals produced in some other region of the brain.
Only visually distinguishable brain features have been considered in this analysis of MRI brain scans. This seems to be a case where every problem appears to be a nail, since the worker's only tool is a hammer.
This reminds me of a previous article where the assertion was made that excessive white matter in the frontal lobes led to pathological lying. I have not seen any follow-up studies to support it nor does this study show any mention of the rest of the brain during the test. As a preliminary test this tiny sample size is ok but before we grant it any credence there needs to be verification from other sources and a much larger study as well.
Reply | Report Abuse | Link to thisAs a basic medical dr mbbs/1950 , i see opinions every now and then reg all researched subjects, some objective and some dogmatic, all challenged or modified as and when newer brains probe.# A good example of the brains fluidity is that when i view 30 Chest xrays a day, the chances are 30% overreading or underreading, and so i am advised to recheck the same opinions after some time, and presto, i am surprised at my own previous opinions!# therefore results and conclusions given even by masters in SciAm i do take and accept with the caution that later findings may not support them.# whatever , i do learn and keep on knowing by reading these great articles.
Reply | Report Abuse | Link to this=other factors being normal, healthy persons' brains anatomy and functions [minds] CAN be maintained balanced by daily judicious siras aasanaas [head stands].
Reply | Report Abuse | Link to thisWhat's really impressive is that these researchers found the cause of their subjects' conditions in the only place they looked: MRI scans!
Reply | Report Abuse | Link to thisWHAT "matters" most is the enviroment the test subjects came from in the first place. all perceptions are simply a comparision of stored experiences to which we compare our sensory data to "shape" our conclusions!
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