如何使两个绘制的函数重叠？

Question

在这张图片中我希望两个高斯相互重叠：

这是一个最小工作示例：

\begin{center}
        \tikzstyle{hidden}=[circle,fill=white!25,minimum size=120pt,inner sep=0pt, path picture={
            \draw[blue,thick,-] plot[domain=-4.5:4.5,samples=50,smooth] ({\x},{4*g(\x)});
        },]
        
        \begin{tikzpicture}[scale=0.95]

        \node (h2)[hidden] at (-2, 0){};
        \node (h1)[hidden] at (2, 0){};
        \node(S_1)[above] at (2,2.1) {$pdf(r|S_1)$};
        \node(S_2)[above] at (-2,2.1) {$pdf(r|S_2)$};

        
        \def\x{1} % replace 1 with desired value here
        \def\x{1} % replace 1 with desired value here   
        \draw[->] (-4,0) -- (4,0) node[right] {$\Psi$};
        \draw[dashed] (0,-0.25) -- (0,2);
        
        

        \draw[-, thick](0,0.1) -- (0,-0.1);

        \foreach \Point in { (-2,0), (2,0) }{
        \node at \Point {$\bullet$};} 

        \foreach \Point in { (1.72,0), (1.91,0),(2.18,0),(-2.08,0),(-1.9,0),(-1.72,0),(2.08,0),(-2.18,0),(1.52,0), (1.31,0),(2.38,0),(-2.48,0),(-1.2,0),(-1.47,0),(2.6,0),(-2.68,0) }{
        \node at \Point {\small $\ast$};}
        
        
        \node [below] at (-0.1,-0.1) {$0$};

        \node [below] at (-2.1,-0.1) {$-A$};
        \node [below] at (2.1,-0.1) {$+A$};
        
        
    \end{tikzpicture}
\end{center}

第二个显示出来的都是这个，但我希望它们两个互相重叠。我该如何实现？也许类似holdMATLAB 中的想法可行，但我不知道 Tikz/LaTeX 中是否存在这种想法。

高斯定义如下：

\tikzset{
    declare function={
        sig = 0.95;
        mu = 0;
        g(\x) = 1/(sig*sqrt(2*pi)) * exp(-1/2 * ((\x-mu)/sig)^2);
    }
}