Scientists at Max Planck Institute for Human Cognitive and Brain Science have offered a conclusive answer to the most important question in neuroscience, ‘How do Humans Think?’ In the new proposal, featured in the journal Science, scientists explained that human thoughts use navigation system of the brain to think.
Place cells and grid cells, situated in the hippocampus and neighboring entorhinal cortex of the brain respectively, are two important cell types that get activated while navigating an environment. These cells form a circuit that allows navigation and orientation.
According to the scientists, brain’s inner navigation system is key to thinking, explaining reasons behind the organization of human knowledge in spatial fashion.
Senior author Christian Doeller explained that storage of information in cognitive spaces of the brain about the surroundings not only limits to geographical data but also includes connection between objects and experiences. ‘Cognitive spaces’ refer to mental maps in which humans arrange their experiences; everything we experience has physical properties that can be organized in varying dimensions, he added.
For example, when thinking about cars, they are ordered on the basis of engine power and weight which may provide either racing cars with low weight and strong engines or caravans with increased weight and weak engines or all combinations in between. Similarly, humans think about their family and friends based on humor, height, income, etc. referring them as humorous of humorless, tall or short, and more or less wealthy, according to Doeller. Relying on the level of interest, information may be stored closer or further away from the cognitive spaces.
A Theory of Human Thinking
In the recent research, group of scientists led by Doeller proposed a framework for cognitive neuroscience or a theory of human thinking by combining individual threads of evidence. It began with findings of place and grid cells in the brains of rodents, which were later discovered to be present in the human brain. These cells display patterns of activity that represent the rodent’s position in the space, for example, while searching for food. A unique pattern of activity represents each position in the space; activity of both place and grid cells together enables the formation of metal map which is stored and reactivated later.
A similar pattern of activity of grid cells can also be observed in human beings, according to the scientists, but it is not limited to navigating through geographical spaces. In a previous study, grid cells were shown to be active while learning new concepts. Interestingly, in a subsequent test, entorhinal cortex was activated in a similar manner, providing coordinate system for human thoughts.
First author Jacob Bellmund said that combination of all the previous findings led to their assumption that human brain stores a mental map, irrespective of what we are thinking. The chain of thoughts can be considered a way through the spaces of thoughts, along various mental dimensions, he added.
Mapping New Experience
According to the neuroscientist, these though processes are useful for making judgments about new situations or objects, which have never been experienced before. Using existing mental maps and relating with different dimensions, humans can predict the similarity between something new and something they already know. On the basis of knowledge of an old concept that is stored in the mental map, human can react adequately. It can be generalize in novel situations and infer how humans should behave, Bellmund said.