The Psi (Ψ) symbol must be much larger, since it is the element that should divide the brain according to the shape of the Psi itself. The symbol should take on the colors of the brain region it is dividing and should appear in 3D, blending naturally with the overall design while preserving the original aesthetic.Remove the hand from the design. Reduce the green color in the upper-left area of the background, making the background whiter and adding subtle leaves. Make the Psi (Ψ) symbol thinner and more delicate, remove the horizontal lines inside the vertical stroke of the symbol, and integrate the Psi symbol with the brain so that they look like a single unified design. Finally, ensure that the color of the Psi symbol adapts smoothly to the dominant colors of the specific brain region it is crossing.