Washington, September 24 : Ask people how they known that a dog is a dog, and they will perhaps say the use of concepts gives them this ability.

Dr. Dharshan Kumaran, from the Wellcome Trust Centre for Neuroimaging at University College London, has now gained significant insights into how the human brain synthesizes concepts that allow people to organize and comprehend the world.

The researcher says that the study sheds light on how conceptual knowledge emerges in the brain, and guides decision making.

The ability to use prior knowledge when dealing with new situations is a defining characteristic of human intelligence, and this is made possible through the use of concepts, which are formed by abstracting away the common essence from multiple distinct but related entities.

"Although a Poodle and a Golden Retriever look very different from each other, we can easily appreciate their similar attributes because they can be recognized as instances of a particular concept, in this case a dog," says Dr. Kumaran, lead study author.

It has long been suggested that the hippocampus, a brain structure critical for memory formation, plays a critical role in the acquisition of conceptual knowledge, but there has been little concrete evidence to support this claim.

Dr. Kumaran and colleagues designed an experimental paradigm that would allow them to track the emergence and application of conceptual knowledge.

During the study, participants played a game in which they had the opportunity to win money by correctly predicting whether it would be sunny or rainy based on the appearance of the night sky, denoted by patterns on a computer screen.

Early on in the experiment, the participants simply memorized the outcome associated with each pattern in isolation. But they quickly noticed that groups of patterns were conceptually related, much in the same way as Poodles and Golden Retrievers.

Structuring the problem in that fashion, the participants solved the task, and even successfully applied their knowledge to a different setting where the concepts were similar but the patterns themselves new.

The researchers used parallel behavioural and neural measures, and observed that a functionally coupled circuit involving the hippocampus and ventromedial prefrontal cortex underpinned the emergence of conceptual knowledge.

However, it was the hippocampus alone that predicted which participants would be able to successfully apply the concepts they had learned to a visually novel setting.

"What this suggests is that perhaps the hippocampus creates and stores these concepts, and passes this information to the prefrontal cortex where it can be put to use, for example in making choices where financial reward is at stake," says Dr. Kumaran.

Taken together, the results highlight the role of the hippocampus in acquiring new concepts, perhaps though its unique networking capacities that allow multiple memories to be related to one another.

"Our study offers neurobiological insights into the remarkable capacity of humans to discover the conceptual structure of their visual experiences, and reveals how so-called ‘memory’ regions like the hippocampus team up with "decision modules" in the prefrontal lobe to put this information to use," concludes Dr. Kumaran.

A research article on the study has been published in the journal Neuron. (ANI)