\documentclass{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows,positioning,shapes.multipart}
\usepackage{fontspec}
\setmainfont{Charis SIL}
\begin{document}
\tikzstyle{m1} = [rectangle, rounded corners, minimum width=3cm, minimum height=1cm,text centered, draw=black, fill=blue!10]
\tikzstyle{arrow} = [thick,->,>=stealth]
\begin{tikzpicture}[node distance=0.5cm,every text node part/.style={align=center}]
  \node (toplab) [] {\large Split-Morphology Hypothesis};
  \node (concept) [below =of toplab] {``John redirected traffic''};
   \node (m1) [m1,below= of concept] {\textbf{Morphological Processing (Derivation)} \\ re+direct};
   \node (s) [m1,below= of m1] {\textbf{Syntactic Processing} \\ Orders Words; Assigns 3SG.PAST to V};
   \node (m2) [m1,below= of s] {\textbf{Morphological Processing (Inflection)} \\ redirect+d};
   \node (ph) [m1,below= of m2] {\textbf{Phonological Processing} \\ /d/ -> [ɪd] / [+cor]\_\_};
   \node (surface) [below= of ph] {[ɹidə`ɹɛktɪd]};
\draw [] (concept) -- (m1);
\draw [] (m1) -- (s);
\draw [] (s) -- (m2);
\draw [] (m2) -- (ph);
\draw [arrow] (ph) -- (surface);

\node (toplab2) [right = of toplab] {\large Single Component Hypothesis};
  \node (concept2) [below = of toplab2] {``John redirected traffic''};

   \node (m12) [m1,below =of concept2] {\textbf{Morphological Processing} \\ re+direct+d};
   \node (s2) [m1,below= of m12] {\textbf{Syntactic Processing} \\ Orders Words};
   \node (ph2) [m1,below = of s2] {\textbf{Phonological Processing} \\ /d/ -> [ɪd] / [+cor]\_\_};
   \node (surface2) [below = of ph2] {[ɹidə`ɹɛktɪd]};
\draw [] (concept2) -- (m12);
\draw [] (m12) -- (s2);
\draw [] (s2) -- (ph2);
\draw [arrow] (ph2) -- (surface2);

\node (toplab3) [right = of toplab2] {\large Whole-Word approach};
  \node (concept3) [below = of toplab3] {``John redirected traffic''};
   \node (s3) [m1,below= of concept3] {\textbf{Syntactic Processing} \\ Requests/Orders Words};
   \node (ph3) [m1,below = of s3] {\textbf{Lexical Retrieval} \\ `redirected'} ;
   \node (surface3) [below = of ph3] {[ɹidə`ɹɛktɪd]};
\draw [] (concept3) -- (s3);
\draw [] (s3) -- (ph3);
\draw [arrow] (ph3) -- (surface3);
\end{tikzpicture}

\end{document}
