Firstly, this is not a signal processing toolbox. Of course, once the data is loaded, there are many matlab functions available for data processing, but few of them are integrated into a GUI interface here. At present, there are no specific functions for processing raw EEG, such as filtering, averaging, etc. For examples of signal processing tools, see the matlab signal processing toolbox and the links below, especially EEGLAB.
This toolbox has been developed to facilitate quick and easy import, visualisation and measurement for ERP data. The toolbox can open and visualise ERP averaged data (Neuroscan, ascii formats), 2D/3D electrode coordinates and 3D cerebral tissue tesselations (meshes). All the features can be explored quickly and easily using the example data provided in the toolbox. The GUI interface is simple and intuitive. The following lists the features already available and some items that could be developed.
gMapMaker enables you to make OziExplorer compatible maps (merged image + .map calibration file) from Google Map tile images (satellite, hybrid, driving maps)
FFTExplorer is a free (GPL) Linux (Xwindows GUI-based) utility that performs spectral analysis on real-time data from a sound card or other source, and can analyze the spectra of various sound file types. It can also accept data from many kinds of applications in plain-text form by way of the "named pipe" feature of Linux (example code provided in the documentation).