Effects of cortical growth rate on wavelength, subcortical growth, and stress in the basic model of cortical folding. Target stresses σ̄r0 = σ̄t0 = 0. Columns: Radial growth Gr; tangential growth Gt; radial stress σr; tangential stress σt. (Row 1) ΓG = 2.5×10−2, scaled time τ = 0.060; (Row 2) ΓG = 2.5×10−3, τ = 0.035; (Row 3) ΓG = 2.5×10−4, τ = 0.014; (Row 4) ΓG = 2.5×10−5, τ = 0.08. The modulus ratio β = 1 in all cases.