Wolfe (1991) reports an example of a search that seems to be parallel for target trials and serial for blank trials:
Here's another example from Wang et al., 1994
Strangely, In Treisman's seminal 1980 paper she also reports a serial slope for color and shape blank trials:
Is anyone familiar with other examples of a dissociation between target-present and target-absent search slopes, in this direction or in the opposite one (e.g., parallel for blank but serial for target trials)?
Thanks,
-Matan