In the rats' piriform cortex, activity patterns elicited by these similar odours were now different as well.

BBC: Sense of smell 'can be improved through training'

Their loss of discrimination was reflected in the piriform cortex, which now produced similar electrical patterns in response to both odours.

BBC: Sense of smell 'can be improved through training'

But in the piriform cortex the odours that rats could tell apart produced distinct patterns of activity, while those they could not distinguish produced identical patterns.

BBC: Sense of smell 'can be improved through training'