Figure 2.

The discrimination thresholds (in log luminance) and the model fits from one participant's pre- and postbeverage testing condition during the placebo session. The abscissa is log pedestal luminance for steady (squares) or pulsed (circles) pedestal paradigm, or log pedestal-Δ-pedestal luminance for the pedestal-Δ-pedestal paradigm (triangles). Open symbols represent data from the prebeverage condition and filled symbols show data from the postbeverage condition. The dashes and lines show the model fits for the pre- and postbeverage data, respectively. The steady pedestal data could be described well by Weber's law with a slope of 1 in the log-log plot.