Concept formation is a hallmark of intelligence, but we know very little of how brains form and use concepts. Using fMRI scanning, Dharshan Kumaran and his colleagues at the Wellcome Trust Centre for Neuroimaging, part of University College London, identified the hippocampus and the ventromedial prefrontal cortex (vMPFC), respectively, as the relevant regions of the brain¹.

Initially, the researchers repeatedly showed  human volunteers pairs of fractal patterns representing the night sky and asked them to forecast rainy or sunny weather based on the patterns. Predictions congruent with certain conceptual rules resulted in cash rewards but participants were not told what these rules were. The participants could simply memorize previous outcomes to make accurate predictions but they also had the opportunity to figure out the concepts that associated given fractal patterns with certain weather outcomes.

In the study’s second phase, participants received less information so as to encourage them to use the rules they had learned. The researchers were thus able to determine who had formed the relevant concepts and those who had not.

The fMRI  scanning revealed a correlation between high activity in the hippocampus (known to be important in learning and memory) in the first phase of the study and the ability to make accurate predictions with less information in the study’s second phase. The vMPFC (known to be important in decision-making) was active in the second phase. Kumaran and his team concluded that the hippocampus forms and stores concepts and passes them to the vMPFC for use in making decisions.

People suffering from amnesia are known to also have problems forming concepts. In 1997  Faraneh Vargha-Khadem of the University College London Institute of Child Health studied three young amnesiacs with hippocampal damage. Upon discovering that the children were able to reach normal levels of speech and language competence, literacy, and factual knowledge she concluded that the acquisition of conceptual knowledge did not involve the hippocampus. However, Kumuran believes the three young amnesiacs’ brains were able to compensate for the hippocampal damage since it was present from birth or a very early age.

On a sidenote, is the plasticity of the brain exemplified by the three young amnesiacs? If so, is this a testament to functionalism?