Freshly cut grass can, for some people, trigger memories of lazy summer days in the park.
Certain smells may even have more power than any other sense to help people recall distant memories.
Now a Norwegian study has uncovered the process behind how waves in the brain make smells stick to distant memories and ‘inner maps’.
‘The signals from your nose translate and connect to memories in an orchestrated symphony of signals in your head,’ the researchers said.
Each of these memories link up with a location, pinpointed on an inner map in the brain, according to the study by the Kavli Institute for Systems Neuroscience in Trondheim, Norway.
The brain, they claim, connects smells to memories in a process where neural networks are linked to brain waves — the electrical signal from a large number of neurons – at around 20-40 Hz.
‘We all know that smell is connected to memories,’ Kei Igarashi, lead author said. ‘We know that neurons in different brain regions need to oscillate in synchrony for these regions to speak effectively to each other.
‘Still, the relationship between interregional coupling and formation of memory traces has remained poorly understood.’
To find out more about this process, researchers designed a maze for rats, where a rat would see a hole to poke its nose into. When poking into the hole, the rat was presented with one of two alternative smells.
One smell told the rat that food would be found in the left food cup behind the rat. The other smell told it that there was food in the right cup.
After three weeks of training, the rats chose the hole with the food more than 85 per cent of the time.
In order to see what happened inside the brain during food-retrieval, 16 electrode pairs were inserted in the brains hippocampus and in different areas of the entorhinal cortex (EC).
The EC-hippocampus system is thought to play an important role in recalling autobiographical memories, particularly ones linked to location, Daily Mail informs.
