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Choice-reaction time (CRT) is an experimental information-processing paradigm. Based on an interference effect in visual attention, the CRT method has been shown to be suitable for measuring sexual orientation in men and women. The present study assessed the potential of the CRT to identify deviant (i.e., pedophilic) sexual interest. Participants were patients from forensic-psychiatric hospitals: 21 child molesters and 21 non-sex offenders. The dependent variable was reaction time in an ostensible seek-and-locate task (i.e., identifying the position of a dot superimposed on a picture of a person). There was an interaction effect between stimulus age category and participant group status: Child molesters took longer to respond to pictures of children relative to pictures of adults. Non-sex offenders showed an opposite pattern (i.e., longer reaction times with pictures of adults than with pictures of children). In addition, the data supported the notion of sexual content induced delay: Subjects took longer for the task with nude stimuli than with clothed ones. A subtractive preference index, derived from the reaction times for child and adult stimulus material, allowed distinguishing participants from both groups almost perfectly (ROC-AUC = .998). We conclude that a match of sexual interest with properties of visual stimuli led to a cognitive interference effect: Attentional resources were drawn from the ostensible task of locating the dot towards exploring the picture. This opens up the possibility of using this interference effect (i.e., the delay of response times) for diagnostic purposes.

We tested whether simulated child sexual abuse (CSA) interviews with computergenerated child avatars could improve interview quality. Feedback was provided not only on question types, as in previous research, but also on whether the conclusions drawn by the interviewers were correct. Twenty-one psychology students (average age M = 24.5) interviewed four different avatars which had a simulated story of either abuse or non-abuse. The participants were randomly divided into two groups: one received feedback on question types and conclusions after each simulated interview and the other one did not receive any feedback. Avatars revealed pre-defined 'memories' as a function of algorithms formulated based on previous empirical research on children's suggestibility. The feedback group used more open-ended and fewer closed questions. They also made more correct conclusions and found more correct details in the last two interviews compared to the no-feedback group. Feedback on both the question types and conclusions in simulated CSA interviews with avatars can improve the quality of investigative interviews in only one hour. The implications for training practice were discussed.

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We provided immediate and detailed feedback in a training paradigm in which simulated interviews with computergenerated avatars were used to improve interviewers' questioning style. Fifty-nine untrained student/interviewers conducted eight interviews each and were randomly assigned to a control, feedback or feedback and reflection group. Compared to the control group, the groups receiving feedback used a higher percentage of recommended questions and retrieved more relevant details while using a lower percentage of not recommended questions and retrieved less wrong details. Only the groups that received feedback reached a reliable change in the proportion of recommended questions. The reflection intervention proposed in the present study did not enhance training effects above and beyond feedback in the present sample. The present study replicated previous findings regarding the role of feedback in improving the quality of investigative interviews, however, failing to show an effect of reflection. Further studies on different reflection tasks are suggested.

Simulated interviews in alleged child sexual abuse (CSA) cases with computer-generated avatars paired with feedback improve interview quality. In the current study, we aimed to understand better the effect of different types of feedback in this context. Feedback was divided into feedback regarding conclusions about what happened to the avatar (outcome feedback) and feedback regarding the appropriateness of question-types used by the interviewer (process feedback). Forty-eight participants each interviewed four different avatars. Participants were divided into four groups (no feedback, outcome feedback, process feedback, and a combination of both feedback types). Compared to the control group, interview quality was generally improved in all the feedback groups on all outcome variables included. Combined feedback produced the strongest effect on increasing recommended questions and correct conclusions. For relevant and neutral details elicited by the interviewers, no statistically significant differences were found between feedback types. For wrong details, the combination of feedback produced the strongest effect, but this did not differ from the other two feedback groups. Nevertheless, process feedback produced a better result compared to outcome feedback. The present study replicated previous findings regarding the effect of feedback in improving interview quality, and provided new knowledge on feedback characteristics that maximize training effects. A combination of process and outcome feedback showed the strongest effect in enhancing training in simulated CSA interviews. Further research is, however, needed.

Purpose. The study extends research by Santtila et al. (2008) by investigating the effectiveness of linking cases of serial homicide using behavioural patterns of offenders, analysed through Bayesian reasoning. The study also investigates the informative value of individual behavioural variables in the linking process. Methods.Offender behaviour was coded from official documents relating to 116 solved homicide cases belonging to 19 separate series. The basis of the linkage analyses was 92 behaviours coded as present or absent in the case based on investigator observations on the crime scene. We developed a Bayesian method for linking crime cases and judged its accuracy using cross-validation. We explored the information added by individual behavioural variables, first, by testing if the variable represented purely noise with respect to classification, and second, by excluding variables from the original model, one by one, by choosing the behaviour that had the smallest effect on classification accuracy. Results.The model achieved a classification accuracy of 83.6% whereas chance expectancy was 5.3%. In simulated scenarios of only one and two known cases in a series, the accuracy was 59.0 and 69.2%, respectively. No behavioural variable represented pure noise but the same level of accuracy was achieved by analysing a set of 15, as analysing all 92 variables. Conclusion.The study illustrates the utility of analysing individual behavioural variables through Bayesian reasoning for crime linking. Feasible applied use of the approach is illustrated by the effectiveness of analysing a small set of carefully chosen variables.Analyses of the behavioural aspects of a crime have increasingly become a part of crime investigation. One domain of this is crime linking; that is, drawing the conclusion that

Purpose. We investigated the feasibility of assessing sexual interest in hetero-and homosexual men using two information-processing methods, namely a choice reaction time task and priming. The participants were expected to have longer reaction times for sexually explicit when compared with non-explicit pictures due to sexual contentinduced delay. In addition, the reaction times of the heterosexual (N ¼ 15) and homosexual (N ¼ 11) men for pictures corresponding with their sexual interest were compared to pictures not corresponding with their sexual interest. Heterosexual men were expected to have longer reaction times during the presentation of sexually explicit female as opposed to male pictures, whereas homosexual men were expected to have the opposite pattern.Method. The participants were presented either sexually explicit or non-explicit male and female target pictures (and primes that preceded the targets in random combinations) while simultaneously performing a choice reaction time task in three phases each containing a total of 160 prime-target pairs.Results. Both expectations were confirmed in phase 1 of the study. In phase 2, the means differed in the expected way, but the effects were not significant. In phase 3, the expected effect was moderated by a complex priming effect.Conclusions. The results suggest that the choice reaction time task is a promising way of measuring sexual interest but that questions of habituation should be given more attention in future studies.