How odours are processed in the brain

The researchers analyzed odour-evoked neuronal activity from thousands of individual neurons in human volunteers from five brain areas. These include piriform cortex — often called the primary olfactory cortex — and four structures, belonging to the medial temporal lobe, that are not considered mainly olfactory areas: the amygdala, the entorhinal cortex, the hippocampus and the parahippocampal cortex.

Using AI, the authors found that piriform cortex with the most accurate odour classification, but the amygdala, hippocampus and entorhinal cortex also contained odour information, albeit with slower and less accurate decoding than the piriform cortex. However, the parahippocampal cortex did not contain any odour information.

The results suggest that odour-processing parts of the brain can integrate information during sensory processing to build ‘concepts’ of odour-associated objects.

https://www.nature.com/articles/s41586-024-08016-5

https://sciencemission.ayurmatrika.com/Single-neuron-representations-of-odours-in-the-human-brain