The GIRI -- Groupe International de Recherche sur lA'Infinitesimal -- was created in 1986 with the aim to gather researchers toward the high dilution questions, such as hormesis, isopathy, homeopathy and the phenomenological and conceptual differences among them. This is the only international scientific society organised exclusively to promote multidisciplinary forums about these subjects. Since 1990, a series of books titled "Signals and Images" has been published regularly by the initiative of Prof. Madeleine Bastide (1935-2007), containing the synthesis of most interesting lectures presented in the GIRI annual symposiums. This third volume "Signals and Images -- Contributions and Contradictions about High Dilution Research" is a legacy from Prof. Madeleine Bastide to the GIRI members. Is a portrait of the GIRI scientific activities, which have been built to strengthen high dilutions and homeopathy through rigorously managed high-level research. It was organised in six parts: epistemology, experimental research / biology, experimental research / physics, clinical research, veterinary research and practice and an epilogue. All chapters were submitted to peer-review.To read it is an interesting way to reach up-to-dated knowledge about High Dilution Research, that has been developed in different parts of the world.