Deception scholars have argued that increasing the liar’s cognitive system artificially can produce deception cues. However, if too much load is imposed the truth tellers’ performance can also be impaired. To address this issue, we designed a veracity task that incorporated a secondary task to increase cognitive load gradually. Also, because deception has been associated with activity in the inferior frontal cortex (IFC), we examined the influence of transcranial direct current stimulation of the IFC on performance. During stimulation, participants truthfully (...) or deceptively indicated whether each of a number of statements shown on screen was true or not. Higher load decreased recall but not general compliance or response times (RTs). Truthful trials yielded higher compliance rates and faster RTs than deceptive trials except for the highest load level. Anodal right stimulation decreased compliance in truthful trials when participants were not overloaded. Truth telling was more vulnerable to cognitive load and tDCS than lying. (shrink)

Over the past decades, the psychological science has accumulated a large corpus of empirical knowledge about police interviews, deception detection, and suspects’ confessions. However, it is unclear whether European police forces’ practices and beliefs are consistent with recommendations derived from this empirical literature. The study described in this report is part of a larger research project examining European police investigators’ practices and beliefs. An online survey was administered to Guardia Civil (n = 89) and Policía Nacional investigators (n = 126). (...) The survey inquired about the length, frequency and electronic recording of interviews, the suspects’ use of their right to remain silent, investigators’ self-reported skills in distinguishing between truthful and deceptive statements, their estimates of the frequency of (false) confessions, and their use of specific interview tactics. The outcomes provide insights into investigators’ knowledge and practices, highlight specific needs, and allow for a comparison between European and North American police forces. (shrink)