Breslin P A, Beauchamp G K, Pugh E N
Monell Chemical Senses Center, Philadelphia, PA 19104, USA.
Percept Psychophys. 1996 Apr;58(3):327-41. doi: 10.3758/bf03206809.
We investigated the ability of subjects to discriminate sugars with a whole-mouth forced-choice paradigm, in which a standard solution was compared with a test solution of varied concentration. Discrimination probabilities were U-shaped functions of test concentration: for 6 subjects and pairwise combinations of fructose, glucose, and sucrose, discriminability always declined to chance over a narrow range of test concentrations. At concentrations < or = 100 mM, maltose was indiscriminable from fructose but discriminable at higher concentrations for 4 subjects. By analogy with the monochromacy of night vision, whereby any two lights are indiscriminable when their relative intensities are suitably adjusted, we call the gustatory indiscriminability of these sugars monogeusia. The simplest account of monogeusia is that all information about the indiscriminable sugars is represented by a single neural signal that varies only in magnitude. The discriminability of maltose from the other sugars at higher concentrations is consistent with the hypothesis that maltose also activates a second gustatory code.
我们采用全口强制选择范式研究了受试者区分糖类的能力，在此范式中，将一种标准溶液与不同浓度的测试溶液进行比较。辨别概率是测试浓度的U形函数：对于6名受试者以及果糖、葡萄糖和蔗糖的两两组合，在较窄的测试浓度范围内，辨别能力总是降至随机水平。在浓度≤100 mM时，4名受试者无法区分麦芽糖和果糖，但在较高浓度下可以区分。类比于夜视的单色性，即当任意两束光的相对强度得到适当调整时就无法区分它们，我们将这些糖类的味觉不可区分性称为单味觉。对单味觉最简单的解释是，关于不可区分糖类的所有信息都由仅在幅度上变化的单个神经信号来表示。麦芽糖在较高浓度下与其他糖类的可区分性与麦芽糖也激活第二种味觉编码的假设一致。
