Three priming mechanisms revealed by time-course patterns.

(A) Definition of clustering axis Δx₁ and Δx₂. Δx₁ refers to the maximum difference between x₁ during the LD priming stage and the steady state value of x₁ in the absence of any stimulus. Δx₂ refers to the difference between the maximum values of x₂ during the HD period with and without priming pretreatment. (B) The time courses of the priming data sets naturally divide into three clusters, corresponding to three priming mechanisms. The pie chart shows the relative frequencies of the priming mechanisms among all the priming parameter sets.