Table 1.

Overview of the equations and symbols used in this paper, assuming a₂ = 0.

Normal forgetting curve	$p\left(t\right)=1-e^{-\left\{r_1\left(t\right)+r_2\left(t\right)\right\}}$
	$=1-exp\left(-{\mu }_1{e}^{-a_{1}t}-\frac{{\mu }_1{\mu }_2}{a_1}\left(1-e^{-a_{1}t}\right)\right)$
Ribot gradient	$p_{\text{Ribot}}\left(t\right)=1-e^{-r_2\left(t\right)}$
	$=1-\exp \left(\frac{-{\text{μ}}_1{\text{μ}}_2}{a_1}\left(1-e^{-a_{1}t}\right)\right)$
Relative retrograde gradient (data transformation)	$rr\left(t\right)=\frac{-{\log }_e\left(1-p_{lesioned}\left(t\right)\right)}{-{\log }_e\left(1-p_{control}\left(t\right)\right)}$
Relative retrograde gradient	$rr\left(t\right)={\left\{\frac{-a_1{\left(1-e^{a_{1}t}\right)}^{-1}}{{\text{μ}}_2}+1\right\}}^{-1}$
Symbol	Description
Free parameters
μ1	Acquired intensity (during learning) of hippocampal/MTL process
μ2	Consolidation rate to the neocortical process
a1	Decline rate of hippocampal/MTL process
a2	Decline rate of neocortical process (assumed to be 0 here)
λ	Lesion size (0 is no lesion; 1 is full lesion)
Derived functions
p(t)	Recall probability as a function of time t
r1(t)	Intensity of the hippocampal (MTL) process
r2(t)	Intensity of the neocortical process
r12(t)	Combined intensity of r1(t) and r2(t)
rr(t)	Relative retrograde gradient