La perception par des magistrats français de l’introduction de données neuroscientifiques dans les expertises psychiatriques pénales : effets sur l’évaluation de l’expertise et la situation pénale de la personne expertisée

Abstract

ObjectiveTo analyze whether the judge's perception of the quality, and scientific basis of a psychiatric expert report of a criminal defendant can vary according to whether or not this evaluation includes neuroscientific data (a written description of a structural neuroimaging MRI scan) and their effects on the decisions made by judges. Experimental psychology has demonstrated a number of cognitive effects arising from exposure to neuroscientific explanations and/or neuroimaging data and which may bias judgments and lead to (mis)interpretations that can affect decisions. This research suggests that including neuroscience evidence in an expert report may impact they way the report is assessed by non-specialists, such as judges, whose work requires them to take into account such reports. MethodWe conducted a study on 41 French judges in order to determine whether their perceptions of the expert report (objectivity, reliability, scientific basis, quality, relevance, credibility, and persuasiveness) and their assessment of risk of recidivism, link between the disorder and offense and the influence of expert report on their decision-making, vary according to whether or not the evaluation includes neuroscientific data. The magistrates had to read a clinical case, summarizing an expertise, with or without neuroscientific data, and then answer various closed (criteria were evaluated using 7-point Likert-scales) and open-ended questions (asking respondents to indicate the reasons underlying their Likert-scale responses). Half of the magistrates received report containing neuroscientific data and the other half a similar report, without this type of data. Quantitative analyses were carried out to assess the effect of the sample's characteristics on the responses given and to compare the results between the two conditions (correlation analyses and Student T). Qualitative analyses, terminological and thematic, were also carried out. ResultsQuantitative and qualitative results show that the presence of neuroscience data in an expert report affects judges’ perceptions of the report and the magistrates’ perceptions of the link between disorder and offense. The judges considered the expert report including neuroscientific data to be more relevant, more objective, better quality, and more reliable than the report without such data. Furthermore, they found the expert's arguments to be more persuasive and that these arguments had a greater scientific basis when the report included neuroscientific data than when such data was absent. Moreover, this phenomenon was stronger in more experienced magistrates than in less experienced magistrates. The qualitative finding shows a greater ability to recognize shortcomings in expert reports when they do not contain neuroscience data. The Expert reports including neuroscience data are perceived as more scientific and objective. ConclusionThe presence of neuroscience data in an expert report affects judges’ perceptions of that report. These effects may be related to cognitive biases described in the literature, in particular the perceived scientific nature of neuroscience data. If judges are aware of their limits when it comes to assessing technical data, they appear relatively unaware that scientific data can induce cognitive biases and thereby affect their perceptions of expert reports.