You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: fisherp.m
    path of file: ./repos/CanlabCore/CanlabCore/Image_computation_tools
    
    the code of the file until where you have to start completion: function [z,p,sig,pt] = fisherp(p,varargin)
% :Usage:
% ::
%
%     function [z,p,sig,pt] = fisherp(p,[alph])
% 

    
function [z,p,sig,pt] = fisherp(p,varargin)
% :Usage:
% ::
%
%     function [z,p,sig,pt] = fisherp(p,[alph])
% 
% :Inputs:
%
%   **p:**
%        values in 4-D array
%
%        1st 3 dims are within images, dim4 = image
%
% :Optional: alpha value for thresholding
% 
% :Outputs:
%
%   **z:**
%        Fisher's combined test statistic, compare to normal
%
%   **p:**
%        p-values for combined test
%
%   **sig:**
%        signficance 1 / 0 binary mask, p < .05 (or alph) FDR-corr
%
%   **pt:**
%        p-value threshold for FDR corrected significance at alph
%
% :Described in:
% Lazar, N. A., Luna, B., Sweeney, J. A., & Eddy, W. F. (2002). 
% Combining brains: a survey of methods for statistical pooling 
% of information. Neuroimage, 16(2), 538-550.
%
% Stouffer, S. A., Suchman, E. A., DeVinney, L. C., Star, S. A., and
% Williams, R. M. 1949. The American Soldier: Vol. I. Adjustment
% During Army Life. Princeton University Press, Princeton.
% 
% Threshold is determined with False Discovery Rate (Benjamini & Hochberg, 1995)
%
% ..
%    tor wager
% ..


if length(varargin) > 0, alph = varargin{1};,else,alph = 0.05;,end