taste without smell

[gib65]

Hello,

 

I'm wondering how a loss of smell affects taste. It's said that the tongue is capable of detecting sweet, sour, bitter, salty, and umami. So what happens when one losing his/her sense of smell? Do they lose the ability to tell the difference between the taste of an orange and the taste of a banana, but still tell they're sweet, or do they lose the ability to taste anything at all.

 

I would also like to know if there are any studies confirming this.

 

Thanks