The Interior Ministry has “cautiously paralyzed” a scientific investigation that, since 2016, has applied brain electrical stimulation to 41 violent prisoners, 15 of them homicides, to study their aggressiveness, according to a spokesman for penitentiary institutions confirmed to EL PAÍS. The experiment, carried out in the prisons of Huelva and Córdoba, consists of providing a slight current of 1.5 milliamperes on the forehead of the inmates and evaluating before and after feelings such as hostility and anger.
Raquel Martín, a 25-year-old psychologist, has been meeting men convicted of murder and robbery with violence in these Spanish prisons since 2016. First, the investigator is interested in the crimes for which they are in prison and carries out a 40-point questionnaire. Inmates must respond if they are false or true statements such as “If I am provoked enough, I can hit another person” or “Sometimes I feel like a barrel of gunpowder about to explode.
Martin then places electrodes on the skull of the inmates and, for half an hour, proceeds to so-called transcranial stimulation with direct current, in order to activate their prefrontal cortex, an area of the brain potentially related to aggression. There are three sessions during three days. When he finishes, he asks the same 40 questions again.
“Before electrical stimulation, prisoners often respond very violently. They say that if you do it, you pay for it. After the three sessions, they feel relaxed and many say they notice a kind of inner peace,” Martin explains. The research is his doctoral thesis. The first results were published in January in the specialized magazine Neuroscience and were published yesterday in the British magazine New Scientist. This afternoon, Penitentiary Institutions has paralyzed the second phase until receiving a report requested to the subdirectorate general of Penitentiary Health. The permission to conduct the study was granted with the PP in power, say the sources of Interior.
The study is coordinated by psychologists Andrés Molero, of the University of Huelva, and Guadalupe Nathzidy Rivera, of the Autonomous University of Baja California, in Mexico. Molero is surprised at the precautionary halt, since the second phase had already been approved by the penitentiary authorities on January 22, 2019 and was to begin this month in Huelva prison.
“Electrical stimulation has a very high potential for use,” explains the psychologist. His results show falls of up to 37% in feelings such as physical aggressiveness. The prisoners signed up for the experiment voluntarily and did not record any relevant adverse effects. A control group, which underwent a paripé of electrical stimulation, did not show a reduction in aggressiveness.
“Transcranial direct current stimulation is a non-invasive, portable, inexpensive and simple technique. If there is scientific evidence that it works, it would be a matter of regulating its use,” says Molero. Recent studies have shown its potential as a treatment for disorders such as anxiety and depression.
German neuroscientist Michael Nitsche has also participated in work in Spanish prisons. “In my opinion, the most interesting result of this study is that it suggests a contribution of prefrontal control in at least subjective aggressiveness, thus improving our basic understanding of the mechanisms of perception of aggression and, perhaps, also neuronal control of aggressive behavior,” says the scientist, from the Leibniz Research Center in Dortmund. “Future studies will tell if this perception of a decrease in aggressiveness corresponds to a real reduction in aggressive behavior,” he warns. In Spain, for the time being, these investigations are pending the decision of Penitentiary Institutions.