Sweetness magnitudes and sweetness differences: Multiple psychological scales for sucrose

Two experiments used sucrose solutions at different concentrations and the method of magnitude estimation to assess: (i) the rule of integration underlying judgments of sweetness intervals, (ii) the sweetness scale operative in judgments of sweetness intervals and (iii) the sweetness scale operative in judgments of individual sweetness magnitudes. Results were consistent with a model of linear subtraction for judgments of sweetness differences. However, the scales that underlay the subtractive interval judgments were non-linearly related to the scales that underlay the (presumably additive) magnitude of sweetness judgments. This outcome suggests multiple psychological representations for sweetness, accounting for at least some of the scale variance observed in previous research.