How to calculate Negentropy using PCA and ICA package

I am assessing the independent components obtained from different ICA algorithms for EEG channels. I use the measures of kurtosis and NegEntropy to estime each components non-gaussianity.

I found the package 'PCA and ICA package' being very good reference and useful in doing my work. However, I am unable to understand how the NegEntropy measure can be calculated?

Is there any MATLAB function to do that.?

Many thanks