Why do coffee drinkers love pumpkin spice lattes?

The autumnal coffee hit that is the pumpkin spice latte is back.

Beloved by many, it is believed to have been invented by Starbucks - the chain said the idea was dreamt up in a seventh floor lab at its Seattle headquarters.

Science journalist Alice Gray, from Cardiff, said the smell rather than the taste of pumpkin spice was key to its success.

She said: "The spice and sugar activates our brain's internal reward systems."

Video edited by Phil John