I herewith would like to present these two bibliographical essays, whose main goal is to unveil subjective diversity from a theoretical standpoint, based on brain activity. This subject represents one of the major enigmas in neuroscience. Both essays were written by Dr. Mario A. Tonnini. Mario A. Tonnini graduated as Doctor in Psychology and was actively involved as a University lecturer for more than 30 years, lecturing Neurobiology and Psychophysiology, constituent parts of the Psychology Study Program. During his long academic career he fostered research, devoting himself for more than 50 years in giving both theoretical and epistemic thought to the intricate problems surrounding the subjective mind. The topic of the subjective mind is part of the essential knowledge that helps us understand its foundations at brain level, so the author decided to promote and disseminate these concepts in authoritative editions. These works are entitled "Subjective significance and its cerebral nature" and "Comments about Consciousness in the words of Stanilas Dehaene", and were published in 2018 and 2 presented at the BA Book Fair. They can be purchased at Kier, Hern ndez and Ant gona booksellers, among others. His next work entitled "Subjective consciousness" will be published this year. It will address the cause of Neuroscience's "million-dollar-question", namely the great paradox in all neuro-scientific studies: the reasons why information triggers a neuro-chemical process, which is common to all brain types (a purely objective mechanism), but its meanings are subjective and therefore different on each individual. In other words, it explains how identical information has a different significance on every person and even on the same individual with such variables as the passage of time and the changing circumstances. And it reveals an appealing scientific subject, the fruit of Dr. Tonnini's continuous research. Representing Dr. Tonnini, I remain at your disposal for whatever additional information you may require for keeping his both previously mentioned publications in your bookstores. The same applies to Dr. Tonnini's future works. Thank you very much. Yours sincerely, Alejandra Rubin