One of the big mysteries of human cognition is how the brain takes ideas and puts them together in new ways to form new thoughts. A region at the front of the brain known as the prefrontal cortex coordinates activity in order help us act in response to a perception and has been shown to play a similarly important role in managing our thoughts. Linking our perception with action, the prefrontal cortex can be considered the glue of cognition.
What makes human thinking so powerful is that we have a library of concepts that we can use to formulate an effectively infinite number of thoughts. Humans can engage in complicated behaviours that, for any other creature on Earth, would require a vast amount of training. Humans can read or hear a string of concepts and immediately put those concepts together to form some new idea.
Yet how the brain bridges the gap between two tiers of neural activity remains a central theoretical discussion in cognitive science.
Studies suggest that two adjacent brain regions allow humans to build new thoughts using a sort of conceptual algebra, mimicking the operations of silicon computers that represent variables and their changing values. According to this theory, thoughts are constructed by the brain representing conceptual variables, answers to recurring questions of meaning such as “What was done?”,“Who did it?” and “To whom was it done?”. The result is that regions of the brain encode mental syntax.
There are two regions in the left superior temporal lobe that carries information about the individual doing the action, and an immediately adjacent region which carries information about the one to whom the action was done to. What neuroscientists have found is that the brain appears to reuse the same patterns across multiple sentences, implying that these patterns function like symbols. Symbols are used over and over again to compose new thoughts.
Moreover, the structure of the thought is mapped onto the structure of the brain in a systematic way. The ability to use a series of repeatable concepts to formulate new thoughts may be part of what makes human thought uniquely powerful.
From a neuroscience perspective we are all divided and discontinuous as mental processes underlying our sense of self (feelings, thoughts and memories) are scattered through different zones of the brain. There is no special point of convergence or cockpit of the self-model, instead they come together through stories. Consequently, the self is a story.
Personal identity critically depends on the creation of stories about the self and one’s life. For most of human history, oral communication and verbal memory were the medium and repository of our accumulated knowledge. Thus it is no coincidence that human beings possess limitless episodic memory and have the impulse to use self-talk.
We do not know what it is about brain function that gives rise to thoughts. Is it the particular kinds of neurons involved? Do conscious thoughts require the activation of specific networks of brain regions or tracts? Do thoughts require activation of perceptual areas of the brain? At this stage of scientific understanding, we do not have enough direct, empirical evidence to answer such questions, however valid they may be. What is clear is that a model of higher cognition that relies on the dynamic combination of conceptual building blocks to formulate thoughts appears to be the most fitting and accurate explanation.
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