New ionoconducting composite membranes to be used as an interface between the skin and the actual electrical instrumentation used to produce an electroencephalogram (EEG) have been developed. The gels are based on lithium salts and PMMA (polymethyl methacrylate) and have been doped with nanometric titanium oxide. The samples have been electrochemically characterized by means of impedance spectroscopy and their structure studied by ATR-FTIR and MAS NMR. Spectroscopic studies indicate interactions between the polymer and oxide dopant. The polymeric electrolytes allowed the registration of good electrophysiological cortical signals either spontaneous or stimulus-related.