The in January released 2.0 version of minted allows you to use the newfloat-package instead of the (rather old) float-package.
If you want to use newfloat, the method for positioning the caption above the source is not the same as Jonas's but rather the following.
\documentclass[a4paper]{scrartcl}
\usepackage{caption}
\usepackage[newfloat]{minted}
\captionsetup[listing]{position=top}
\begin{document}
\begin{listing}[H]
\caption{This is above the code.}
\inputminted{matlab}{myfile.m}
\label{lst:the-code}
\end{listing}
\end{document}

Important: you have to place the \caption-command above your source-code within the listing-float.
The \captionsetup only applies correct spacing but you have to place the command at the right position yourself.
matlab-prettifierpackage; see this answer. – jub0bs Apr 28 '14 at 15:29