 This paper provides an overview of the existing techniques used to remove physiological artifacts from electroencephalogram e.g. signals. These include regression, filtering, blind-source separation, wavelet transform, empirical mode decomposition, singular spectrum analysis, and independent vector analysis. Hybrid approaches combining two or more of these techniques have also been developed and shown to provide better results than single techniques. This article was authored by Maria Dei Sumathe, Padmacha Mitidotti, and Bhattala Tiramala Krishna.