Fig 4. The motivational bias of cortisol release during gum chewing.

The subjects were asked to chew a palatable (TO-gum, positive motivational outcome) and unpalatable (SL-gum, negative motivational outcome) gum. A: The visual analogue scale of odour B: The visual analogue scale of taste C: Total saliva volume D: Cortisol concentration Statistical significance was P <0.05, according to Wilcoxon signed-rank tests.