(a,f,k) Psychometric functions for the recording sessions of rats Bertrand (a), Edgar (f) and Fernando (k) (mean ± standard deviation across sessions and logistic fit). (b,g,l) Histograms of preference indices for the same individual animals. Blue and red outlines indicate subpopulations with significant short and long preferences, respectively. (c,h,m) Averaged, normalized PSTHs of the two subpopulations outlined in (b,g,l) for trials in which the a near-boundary stimulus interval (1.62 s) was judged as long (mean ± SEM). (d,i,n) same as in (c,h,m) for short judgment trials. (e,j,o) Normalized PSTHs of all neurons for each animal for trials in which the longest stimulus interval was presented. Blue and red ticks indicate cells with significant short and long preferences, respectively.