Using virtual reality in criminological research

Since the pioneering early studies of the 1990s hinted at its promise as a research method, virtual reality (VR) technology has increasingly been used by social scientists. Given recent developments that have greatly enhanced realism, reduced costs, and increased possibilities for application, VR seems well on its way to become an established research tool in the social sciences. However, as with other ethodological innovations, the field of criminology hasbeen slow to catch on. To address this gap, this article explores the potential of VR as a tool for crime research. It provides readers with a brief and non-technical description of VR and its main elements and reviews severalapplications of VR in social scientific research that are potentially relevant for criminologists. By way of illustration, we identify and discuss in more detail different areas in which we think the field of criminology can particularly benefit from VR and offer suggestions for research. Some of the equipment available on the consumer market is also reviewed.In conjunction, the different sections should equip readers interested in applying VR in their own research with a fundamental understanding of what it entails and how it can be applied

Task and spatial frequency modulations of object processing: an EEG study.

Visual object processing may follow a coarse-to-fine sequence imposed by fast processing of low spatial frequencies (LSF) and slow processing of high spatial frequencies (HSF). Objects can be categorized at varying levels of specificity: the superordinate (e.g. animal), the basic (e.g. dog), or the subordinate (e.g. Border Collie). We tested whether superordinate and more specific categorization depend on different spatial frequency ranges, and whether any such dependencies might be revealed by or influence signals recorded using EEG. We used event-related potentials (ERPs) and time-frequency (TF) analysis to examine the time course of object processing while participants performed either a grammatical gender-classification task (which generally forces basic-level categorization) or a living/non-living judgement (superordinate categorization) on everyday, real-life objects. Objects were filtered to contain only HSF or LSF. We found a greater positivity and greater negativity for HSF than for LSF pictures in the P1 and N1 respectively, but no effects of task on either component. A later, fronto-central negativity (N350) was more negative in the gender-classification task than the superordinate categorization task, which may indicate that this component relates to semantic or syntactic processing. We found no significant effects of task or spatial frequency on evoked or total gamma band responses. Our results demonstrate early differences in processing of HSF and LSF content that were not modulated by categorization task, with later responses reflecting such higher-level cognitive factors

Gas-free calibrated fMRI with a correction for vessel-size sensitivity

Calibrated functional magnetic resonance imaging (fMRI) is a method to independently measure the metabolic and hemodynamic contributions to the blood oxygenation level dependent (BOLD) signal. This technique typically requires the use of a respiratory challenge, such as hypercapnia or hyperoxia, to estimate the calibration constant, M. There has been a recent push to eliminate the gas challenge from the calibration procedure using asymmetric spin echo (ASE) based techniques. This study uses simulations to better understand spin echo (SE) and ASE signals, analytical modelling to characterize the signal evolution, and in vivo imaging to validate the modelling. Using simulations, it is shown how ASE imaging generally underestimates M and how this depends on several parameters of the acquisition, including echo time and ASE offset, as well as the vessel size. This underestimation is the result of imperfect SE refocusing due to diffusion of water through the extravascular environment surrounding the microvasculature. By empirically characterizing this SE attenuation as an exponential decay that increases with echo time, we have proposed a quadratic ASE biophysical signal model. This model allows for the characterization and compensation of the SE attenuation if SE and ASE signals are acquired at multiple echo times. This was tested in healthy subjects and was found to significantly increase the estimates of M across grey matter. These findings show promise for improved gas-free calibration and can be extended to other relaxation-based imaging studies of brain physiology

Clinical mapping of cerebrovascular reactivity using MRI: a framework for reaching consensus

Cerebrovascular reactivity (CVR) mapping using a CO2 stimulus assesses the ability of cerebral vessels to satisfy the demand for an increase in cerebral blood flow. In recent years the number of clinical CVR exams has greatly increased1. However, so far the application of CVR mapping across the world has been variable2 due to a lack of standardisation3. Here we identify a process by which convergence and interoperability may be attained, enabling more widespread adoption of CVR in the clinic

Oncological and functional outcomes of trans-oral robotic surgery for pyriform sinus carcinoma: A French GETTEC group study

International audienceBackground Pyriform sinus carcinomas (SCC) present specific functional and oncological issues. The recent advent of trans-oral robotic surgery (TORS), as a conservative procedure, has opened up new perspectives. Objectives To present the oncological and functional outcomes of TORS for pyriform sinus SCC. Materials and methods We included, retrospectively, all TORS procedures for pyriform sinus SCC performed between 2009 and 2017 in eight French tertiary referral centers. We excluded lesions involving the pyriform sinus that had developed from the oropharynx, larynx, or other anatomic sub-sites of the hypopharynx. Results We included 57 TORS procedures. Median hospital stay was 10 days. A preventive tracheotomy was performed in seven cases (12%), and all were successfully decannulated. Oral re-feeding was possible for 93%, after a median of 5 days. The main surgical complications were hemorrhages (three cases), all successfully handled, although 2 patients with heavy comorbidities died from blood loss in the days after. Adjuvant therapy was proposed in 31 cases (54%), including two cases of salvage surgery (total pharyngolaryngectomy). After a median follow-up of 23 months, overall and disease-free survival were, respectively, 84% and 74% at 24 months, and 66% and 50% at 48 months. At the end of follow-up, organ preservation rate was 96%. None of the surviving patients needed a tracheotomy and oral diet was possible for 96%. Conclusion The functional and oncological outcomes of TORS for pyriform sinus cancer are encouraging, and this procedure can be considered safe for selected early or moderately advanced cases as a conservative treatment

Identifying object categories from event-related EEG: Toward decoding of conceptual representations

Contains fulltext : 99404.pdf (publisher's version ) (Open Access)Multivariate pattern analysis is a technique that allows the decoding of conceptual information such as the semantic category of a perceived object from neuroimaging data. Impressive single-trial classification results have been reported in studies that used fMRI. Here, we investigate the possibility to identify conceptual representations from event-related EEG based on the presentation of an object in different modalities: its spoken name, its visual representation and its written name. We used Bayesian logistic regression with a multivariate Laplace prior for classification. Marked differences in classification performance were observed for the tested modalities. Highest accuracies (89% correctly classified trials) were attained when classifying object drawings. In auditory and orthographical modalities, results were lower though still significant for some subjects. The employed classification method allowed for a precise temporal localization of the features that contributed to the performance of the classifier for three modalities. These findings could help to further understand the mechanisms underlying conceptual representations. The study also provides a first step towards the use of concept decoding in the context of real-time brain-computer interface applications.12 p