Fig. 3

Schematic overview of a typical exposure experiment for the domestic cats. This experiment was done for each cat. The different shapes (square, circle, triangle and diamond) represent the various plant materials the cats were exposed to. A negative control (not shown in the figure) was always offered together with each plant material. The wash-out period is represented by a tilde. The responses are an example; these are not results. On the first exposure day circle and triangle were removed from the cat as soon as a positive response was scored. This was done to prevent the cat from not responding to diamond because of loss of interest, fatigue or saturation to active compounds that also may be present in the plant materials the cat had already been exposed to during the experiment on this day. Square and diamond were offered first (in random order) on the second day the cat was tested, because no positive response was observed on the previous testing day. This was done for the same reasons as previously mentioned. Diamond was removed when the cat was scored positive for this sample. Triangle and circle were offered to the cat last (in random order), to try to confirm the results obtained on the first test day, and also to establish that the cat’s environment (e.g., noises, other cats present) and its physical and mental state were not preventing the cat from responding positively. This method was repeated on day 3: the sample to which the cat did not respond positively (square) was offered first, followed by samples to which the cat had already responded positively. In this example the cat would have been scored negative for square and positive for circle, triangle and diamond. Pos., positive; Neg., negative