Primate metacommunication

Jonah Lehrer, mastermind behind Front Cortex, has "always been fascinated by tip-of-the-tongue moments. It's estimated that, on average, people have a tip-of-the-tongue moment at least once a week. Perhaps it occurs when you run into an old acquaintance whose name you can't remember, although you know that it begins with the letter "J." Or perhaps you struggle to recall the title of a recent movie, even though you can describe the plot in perfect detail.
What's interesting about this mental hiccup is that, even though the mind can't remember the information, it's convinced that it knows it, which is why we devote so many mental resources to trying to recover the missing word. (This is a universal experience: The vast majority of languages, from Afrikaans to Hindi to Arabic, even rely on tongue metaphors to describe the tip-of-the-tongue moment.) But here's the mystery: If we've forgotten a person's name, then why are we so convinced that we remember it? What does it mean to know something without being able to access it?
The larger question is how the mind decides what to think about. After all, if we really don't know the name - it's nowhere inside our head - then it's a waste of time trying to find it. This is where metacognition, or thinking about thinking, comes in handy. At any given moment, we automatically monitor the flux of thoughts, emotions and errata flowing in the stream of consciousness. As a result, when a name goes missing we immediately analyze the likelihood of being able to remember it. Do we know the first letter of the name? Can we remember other facts about the person? Are we able to remember the first names of other acquaintances from high school? Based on the answer to these questions, we can then make an informed guess about whether or not it's worth trying to retrieve the misplaced memory.
Interestingly, a new experiment with a variety of primates (gorillas, chimpanzees, bonobos and orangutans) demonstrated that great apes also demonstrate some rudimentary metacognitive skills. The study, conducted by Josep Call at the Max Planck Institute for Evolutionary Anthropology, involved presenting the primates with two hollow tubes. One of the tubes came with a food reward, while the other was empty. The apes were then observed as they searched for the reward.

Read on for the results.