How to perform this specific convolution in matlab?

Hey I'm struggling with the maths behind a convolution.

I currently have a matrix to represent PSF of 40x40. I also have a 3D matrix, 10 x 10 x 40, f, and am currently performing the convolution with the following code:

    rates = conv2(f, PSF, 'same');

Is this the same convolution performed in this: http://mtthw.net/convolution.jpg