Monell Chemical Senses Center, 3500 Market Street, Philadelphia, PA 19104-3308, USA.
Chem Senses. 2011 Sep;36(7):581-7. doi: 10.1093/chemse/bjr024. Epub 2011 Mar 25.
Psychophysical judgments often depend on stimulus context. For example, sugar solutions are judged sweeter when a tasteless fruity aroma has been added. Response context also matters; adding a fruity aroma to sugar increases the rated sweetness when only sweetness is considered but not when fruitiness is judged as well. The interaction between stimulus context and response context has been explored more extensively in taste-odor mixtures than in taste-taste mixtures. To address this issue, subjects in the current study rated the sourness of citric acid mixed with quinine (bitter), sodium chloride (salty), and cyclamate (sweet) (stimulus context). In one condition, subjects rated sourness alone. In another, subjects rated both sourness and the other salient quality (bitterness, saltiness, or sweetness) (response context). Sourness ratings were most sensitive to response context for sour-salty mixtures (i.e., ratings of sourness alone exceeded ratings of sourness made simultaneously with saltiness) and least sensitive to context for the sour-sweet mixtures (sourness ratings made under the 2 conditions were essentially identical). Response-context effects for the sour-bitter mixture were nominally intermediate. The magnitudes of these context effects were related to judgments of qualitative similarity between citric acid and the other stimuli, consistent with prior findings. These types of context effects are relevant to the study of taste-taste mixture interactions and should provide insight into the perceptual similarities among the taste qualities.
心理物理判断往往取决于刺激环境。例如，当添加无味的果香时，糖水会被认为更甜。响应环境也很重要；当只考虑甜度时，添加果香会增加糖的甜度，但当判断果味时则不会。与味觉-味觉混合物相比，在味觉-嗅觉混合物中，刺激环境和响应环境之间的相互作用得到了更广泛的研究。为了解决这个问题，当前研究中的受试者对柠檬酸与奎宁（苦）、氯化钠（咸）和环己胺（甜）混合（刺激环境）的酸味进行了评价。在一种情况下，受试者仅对酸味进行评价。在另一种情况下，受试者同时对酸味和其他显著特征（苦味、咸味或甜味）进行评价（响应环境）。对于酸咸混合物，酸味评价对响应环境最敏感（即，单独评价酸味的评价高于同时评价咸味的评价），而对于酸甜混合物，对环境的敏感性最低（在两种条件下进行的酸味评价基本相同）。对于酸苦混合物，响应环境的影响则名义上处于中间水平。这些上下文效应的大小与柠檬酸与其他刺激物之间的定性相似性判断有关，与先前的发现一致。这些类型的上下文效应与味觉-味觉混合物相互作用的研究有关，并应提供对味觉质量之间的感知相似性的深入了解。
