The Ministry of the Interior has "precautionary paralyzed" a scientific investigation that, since 2016, has applied a cerebral electrical stimulation to 41 violent prisoners, 15 of them homicidal, to study their aggression, as has confirmed to EL PAÍS a spokesman of Penitentiary Institutions. The experiment, carried out in the prisons of Huelva and Córdoba, consists of supplying a light current of 1.5 milliamps on the forehead of the inmates and evaluating before and after feelings such as hostility and rage.
Raquel Martín, a psychologist of 25 years, since 2016 has been in these Spanish prisons with men convicted of murder and robbery with violence. First, the researcher is interested in the crimes for which they are in jail and makes a questionnaire of 40 points. 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 powder keg about to explode".
Later, Martín placed electrodes in the skull of the inmates and, for half an hour, proceeded to the so-called transcranial stimulation with direct current, with the aim of activating his prefrontal cortex, an area of the brain potentially related to aggression. They are three sessions for three days. When finished, go back to asking the same 40 questions.
"Before electrical stimulation, prisoners often respond very violently. They say that if they do it, they pay it. After the three sessions, they feel relaxed and many say they notice a kind of inner peace, "explains Martín. The research is his doctoral thesis. The first results were published in January in the specialized magazine Neuroscience and they were disclosed yesterday in the British magazine New Scientist. This afternoon, Penitentiary Institutions has paralyzed the second phase until receiving a report requested from the General Subdirectorate of Penitentiary Health. The permission to carry out the study was granted with the PP in power, underline Interior sources.
The study is coordinated by psychologists Andrés Molero, of the University of Huelva, and Guadalupe Nathzidy Rivera, from the Autonomous University of Baja California, in Mexico. Molero shows his surprise at the precautionary paralysis, since the second phase had already been approved by the prison authorities and was going to begin to be carried out this month in the Huelva jail.
"Electrical stimulation has a very high potential for use," explains the psychologist. Their results show drops of up to 37% in feelings such as physical aggression. The prisoners voluntarily signed up for the experiment and did not register any relevant adverse effects. A control group, which was subjected to an electric stimulation paripé, did not show a reduction in aggressiveness.
"Transcranial direct current stimulation is a non-invasive, portable, cheap and simple technique. If there is scientific evidence that it works, it would be a matter of regulating its use, "defends Molero. Recent studies they have shown their potential as a treatment for disorders such as anxiety and depression.
The German neuroscientist Michael Nitsche He has also participated in the 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, which improves our basic understanding of the mechanisms of perception of aggression and, perhaps, also of the neuronal control of aggressive behavior, "says the scientist, from the Leibniz Research Center in Dortmund. "Future studies will say whether this perception of a decrease in aggressiveness corresponds to a real reduction in aggressive behavior," he warns. In Spain, at the moment, these investigations are pending of the decision of Penitentiary Institutions.