. 2016 Jun 22;10:51. doi: 10.3389/fnsys.2016.00051

Table 2.

Overview of all hypothetical changes regarding additive and multiplicative shifts of the expected values μ₀ and for increased and decreased activity.

	Additive shift	Multiplicative shift
Activity increases	μ₁ = μ₀ + δ_in	μ₁ = δ_inμ₀
	(δ_in > 0)	(δ_in > 1)
Activity decreases	μ₁ = μ₀ + δ_de	μ₁ = δ_deμ₀
	(−μ₀ < δ_de < 0)	(0 < δ_de < 1)

The additive shift for the decreased activity cannot be less than the expected value μ₀ because the PSTH has no negative values. Note that for the additive shift δ_de has a negative value.