Monkeys had higher confidence in their ability to remember an image when the visual contrast was high. These kinds of metacognitive illusions — false beliefs about how we learn or remember best — are shared by humans, leading brain and cognitive scientists to believe that metacognition could have an evolutionary basis.
Actually, they merely assume that and rely on increasingly casuistical experiments to provide support.
Instead of getting a reward right away — to eliminate decisions based purely on response-reward — the monkey next sees a betting screen to communicate how certain he is that he’s right. If he chooses a high bet and is correct, three tokens are added to a token bank. Once the token bank is full, the monkey gets a treat. If he gets the task incorrect and placed a high bet, he loses three tokens. If he placed a low bet, he gets one token regardless if he is right or wrong.
Researchers manipulated the fluency of the images, first making them easier to see by increasing the contrast (the black image), then making them less fluent by decreasing the contrast (the grey image).
The monkeys were more likely to place a high bet, meaning they were more confident that they knew the answer, when the contrast of the images was increased.
“Fluency doesn’t affect actual memory performance,” Ferrigno says. “The monkeys are just as likely to get an answer right or wrong. But this does influence how confident they are in their response.”
Since metacognition can be incorrect through metacognitive illusion, why then have humans retained this ability?
“Metacognition is a quick way of making a judgment about whether or not you know an answer,” Ferrigno says. “We show that you can exploit and manipulate metacognition, but, in the real world, these cues are actually pretty good most of the time.” Paper. (paywall) – Stephen Ferrigno, Nate Kornell, Jessica F. Cantlon. A metacognitive illusion in monkeys. Proceedings of the Royal Society B: Biological Sciences, 2017; 284 (1862): 20171541 DOI: 10.1098/rspb.2017.1541
Why are human obviously conscious whereas this kind of research and speculation needs to be done for monkeys – setting them up in a human-constructed environment – to do things they may not otherwise bother with? Don’t complain; it is a fun, humane job op for the monkeys and one senses that there is room for many, many more papers of this type.
See also: Large numbers, even of atheists, doubt that evolution explains human consciousness
Are apes entering the Stone Age?