Figure 3.

Odor mixture discrimination boundary is not necessarily orthogonal to the training set. (A) Training stimuli (f_A + f_B = 100; black filled circles) and lower concentration test stimuli (f_A + f_B = 50; red circles). The training reward boundary is indicated by the magenta diamond. Note that the boundary shifted in this experiment to f_A = 3·f_B. The yellow line indicates the classification boundary for a ratio computation (f_A/f_B = 3) while the blue line indicates the classification boundary orthogonal to the training stimulus set (y = f_A − f_B = c). See also Figure 1A for details of legend. (B) Performance of one rat on training and test stimuli with a shifted training reward boundary. The independent variable is the ratio of mixture components f_A/f_B. (C) The same data as in (B) but where the independent variable is the difference of mixture components, f_A − f_B.