Table 2.

Stimuli pairs presented in an experiment session

First odor	A1 + A2	C1 + C2	C1 + C2	E1 + E2	B1 + B2	D1 + D2	A1 + A2	D1 + D2	B1 + B2	E1 + E2
Second odor	C1 + C2	A1 + A2	E1 + E2	C1 + C2	D1 + D2	B1 + B2	D1 + D2	A1 + A2	E1 + E2	B1 + B2
First odor	A1	C1	C1	E1	B1	D1	A1	D1	B1	E1
Second odor	C1	A1	E1	C1	D1	B1	D1	A1	E1	B1
First odor	A2	C2	C2	E2	B2	D2	A2	D2	B2	E2
Second odor	C2	A2	E2	C2	D2	B2	D2	A2	E2	B2

Thirty randomized trials given in one experiment session are specified. Each adjacent pair of rows of the same column represents a pair of stimuli presented in successive order in a single trial, denoted as “first” and “second” odor. These pairs were ranked for their relative and absolute pleasantness as described in the text. Rows 3 through 6 represent the separated constituents of the mixtures diluted with clean air to the overall flow of their respective mixtures. Following the 30 trials of pleasantness ratings, the separated mixture constituents were also ranked for their intensities (i.e., 10 randomized stimuli: A1 through E1 and A2 through E2).