I developed my first research activities in the image processing and pattern recognition laboratory (TIRF), which became, in January 1998, a joint unit of CNRS, the images and ignals laboratory (LIS), by merging two laboratories, TIRF and CEPHAG. In January 2007, by merging of three laboratories: LIS, LAG (Automatic control lab.) and ICP (Speech lab.), is born the large laboratory GIPSA-lab. I first worked under the supervision of Prof. Jeanny Hérault on modelisation of neural networks and design of artificial neural networks algorithms, with applications in signal and ilmage processing. Since end of 80's, I develop my own research activities, with my PhD students and collaborators, mainly on source separation and independent component analysis (ICA) and their applications. After theoretical contributions on linear instantaneous mixtures (from 1984), convolutive mixture (from 1987, but especially after 1990), I was interested by source separation in nonlinear mixtures (especially from 1996). In addition, under the impulse of my colleague and friend, Dr. Massoud Babaie-Zadeh from Sharif University of Technology (Tehran, Iran), I also addressed sparse representation and sparse sourse separation in under-determined mixtures.