"What sorts of ‘rules’ could possibly capture all of what we think of as intelligent behaviour however? Certainly there must be rules on all sorts of different levels. There must be many ‘just plain’ rules. There must be ‘metarules’ to modify the ‘just plain’ rules; then ‘metametarules’ to modify the metarules, and so on. The flexibility of intelligence comes from the enormous number of different rules, and levels of rules. The reason that so many rules on so many different levels must exist is that in life, a creature is faced with millions of situations of completely different types. In some situations, there are stereotyped responses which require ‘just plain’ rules. Some situations are mixtures of stereotyped situations - thus they require rules for deciding which of the 'just plain’ rules to apply. Some situations cannot be classified - thus there must exist rules for inventing new rules ... and on and on. Without doubt, Strange Loops involving rules that change themselves, directly or indirectly, are at the core of intelligence. Sometimes the complexity of our minds seems so overwhelming that one feels that there can be no solution to the problem of understanding intelligence - that it is wrong to think that rules of any sort govern a creature's behaviour, even if one takes ‘rule’ in the multilevel sense described above" (Douglas Hofstadter, Gödel, Escher, Bach).
We cannot take decisions without involving emotions. This conclusion of modern psychology goes against the grain of what was believed to be the case about the nature of rational behaviour for most of the 20th century. The conventional picture was that at the bottom of the hierarchical complexity of the human brain is the brain stem, which controls bodily functions like heartbeat, breathing, and body temperature. At the next higher level is the diencephalon, which regulates hunger pangs and sleep cycles etc. Then comes the limbic region, which generates and controls emotions (violence, lust, impulsive behaviour, etc.). These three levels of brain complexity are common to all mammals, including humans. Lastly there is the prefrontal cortex, predominantly responsible for our reasoning power and intelligence etc. Although it enables us to suppress emotions to a small or large extent, it is wrong to think that this ‘rationality’ portion of our brain can completely overpower or overrule what the three hierarchically lower parts of the brain tend to do. In other words, it is impossible for us to make decisions which are completely dispassionate or ‘reasoned’.
It is also true that a substantial portion of the prefrontal cortex is involved in our emotional behaviour. How do we ‘manage’ our emotions? We do so by thinking about them, and the thinking is done mainly by the prefrontal cortex.
The term 'metacognition' is used for the capacity of our prefrontal cortex to contemplate about our own mind.
The frontal cortex knows when we are, say, angry. In fact, practically every emotional state comes with self-awareness attached to it. This enables us to figure out or ‘think’ why we are feeling the way we are feeling. Thus we humans are able to exercise a certain degree of control over our emotions by what is commonly called ‘rational thinking’. This is also how we make decisions. The emotional brain is constantly sending out signals about its likes and dislikes. The prefrontal cortex monitors these emotional outputs and tries to decide which signals to take seriously and which ones to overrule. Although the rational brain cannot silence emotions, it can help figure out which ones should be followed.
A highly readable account of the role of intuition and emotions in our decision-making process has been given in the 2009 book How We Decide by Jonah Lehrer.
Unlike other regions ('columns') of the cortex, which specialize in processing specific types of stimuli, the cells of the prefrontal cortex can process whatever kind of data they need to process. This enables our brain to look at a given problem from a variety of vantage points, and even come out with creative solutions.
How does the prefrontal cortex accomplish this? The answer has to do with its special kind of memory called the working memory. It is a short-term memory, but it has a persistence feature. It is a meeting ground, and also a melting pot, of information from various sources. Neurons in this part of the brain fire in response to a stimulus, and then keep on firing for several seconds after the stimulus has disappeared. This allows the brain to make creative associations. This is the so-called restructuring phase of problem-solving: Here information is mixed together in new ways and overlapping of ideas occurs, leading to new insights. The resultant novel neural wiring enables you to identify the answers you were looking for. This is an important feature of human intelligence.
The emotional brain is important too
Excessively rational thinking can backfire, because it often amounts to suppressing what the primitive brain is trying to tell us. This problem arises because the rational brain is not an infinitely powerful supercomputer, meaning that rational analysis cannot always provide the best solution to a complicated problem. The cumulative wisdom buried in the (much larger) primitive brain must also be used.
The psychologist George Miller demonstrated in his essay ‘The Magical Number Seven, Plus or Minus Two’ that the conscious brain can only handle about seven pieces of data at any one moment. The computational circuitry of the rational part of our brain is only a tiny fraction of the total capacity of the brain, ‘just a few microchips within the vast mainframe of the mind.’ As a result, too many choices, or too much data, can overwhelm the prefrontal cortex, leading to bad decisions. The trick lies in learning when to trust your intuitions more than your reasoning power. ‘Because working memory and rationality share a common cortical source - the prefrontal cortex - a mind trying to remember lots of information is less able to exert control over its impulses. The substrate of reason is so limited that a few extra digits can become an extreme handicap’ (Lehrer 2009). The fact of life is that the rational part of our brain (which is really a very recent novelty on the evolutionary time scale) has a rather slow and small, even erratic, CPU. Too much information can interfere with understanding. When the prefrontal cortex is overwhelmed, correlation is confused with causation, and people tend to make theories out of coincidences.
And yet, excessive dependence on the emotional brain can be risky too. The ideal situation is that exemplified by, say, a champion chess player. Through an unhurried analysis of the games he won or lost, he builds up experience (turning mistakes into educational events) which gets ‘internalized’ into his emotional brain. In due course, it becomes ‘second nature’ for him to make the right moves, not having to consciously analyze the consequences of too large a number of prospective moves. The emotional brain is a huge supercomputer, with massive parallel-processing capabilities. It is neither easy, nor perhaps desirable, to shut off this supercomputer, no matter how hard you try to do so through your prefrontal cortex.