This work analyses the evolution of the scientific visibility of the neurophysiologist José Manuel Rodríguez Delgado. It examines the longitudinal evolution from 1955 to 2013 of an article (Delgado, Roberts, & Miller, 1954) studying the neurological basis of learning and motivation and compares it with a coetaneous article (Olds & Milner, 1954) with a similar subject and methodology. Both studies have been essential in Psychology. This work analyses the number of times each article has been cited between 1955-1984 and 1985-2013. The results show that the visibility of James Olds and Peter Milner's article (expressed in number of citations between 1955-1984 and 1985-2013) has longitudinally increased (p < .001), whereas the number of citations received by José Manuel Rodríguez Delgado et al.'s article has significantly reduced (p < .001). The results are discussed and the low visibility of Delgado's article is explained through historical and social factors, including the growing concern about compliance with bioethical and research guidelines and the controversial media projection of the Spanish scientist, not by the intrinsic value or the scientific repercussion of the compared articles.
Keywords: José Manuel Rodríguez Delgado; electrical brain stimulation; history of psychology; quantitative analysis.