Dissociating pleasantness and intensity with quinine sulfate/sucrose mixtures in taste.

Independent experimental manipulation of subjective intensity and hedonic tone is required if one wants to study their separate effects on brain activity and behavior. This is problematic because hedonic tone and subjective intensity are related, leading to a pleasantness change each time the stimulus intensity is altered. In the present study, a solution to this problem was explored by combining a pleasant-tasting substance (sucrose) and a bad-tasting substance (quinine sulfate) into a number of different isointense mixtures. Here we show that subjective intensity as well as pleasantness can be accurately predicted, particularly in midrange, only if one corrects for mixture suppression.