How to use Matlabs perfcurve and confusion.getMatrix for ROC curves and confusion matrices [on hold]

I am trying to use matlab in order to plot the ROC curve for Data of signal detection (audio signal detected by mouse).

I used the commands:

[c_matrix,Result,RefereceResult]= confusion.getMatrix(truth ,mouse);    
[X,Y] = perfcurve(truth,mouse,1);  
plot(X,Y);    
hold on;      
x = 1 - Result.Specificity;    
y = Result.Sensitivity;    
plot(x,y,'-o','MarkerFaceColor',[0.929,0.694,0.125],'MarkerSize',10);    

Where:

truth(i)=

\left\{

\begin{array}{}

0 \text{ } \text{ if a signal should be detected in the i'th trial}\\

1 \text{ } \text{ if a signal should not be detected in the i'th trial}\\

\end{array}

\right.

and

mouse(i)=

\left\{

\begin{array}{}

0 \text{ } \text{ if the mouse detected a signal in the i'th trial}\\

1 \text{ } \text{ if the mouse didn't detect a signal in the i'th trial}\\

\end{array}

\right.

I attach here the figure I got.

It seems to me that the ROC function is not correct because, if I understood correctly, the point $$(1-specificity,sensitivity) = (FP,TP)$$

should be on the ROC curve.

In general, I think I am having troubles understanding some stuff:

**1**. what should be the input to [X,Y] = perfcurve(labels,scores,posclass).

**2**. Is 'labels' really the truth and 'scores' the performent?

**3**. Does '0' denotes a detection or maybe '1'?

**4**. Also, what does it mean to plug 'posclass = 1'?

(I did it because I didn't know what to put in there...)

I've been looking for houres by now in the internet and in the function description, and I can't figure this thing out..

Any help will be great.

Thanks!