Brain wave P300: a comparative study of various forms of criminal activity.

BACKGROUND: This comparative and comprehensive study builds on a previous study comparing the P300 wave of impulsively violent delinquents and a non-impulsive non-delinquent group. The purpose was to investigate changes in P300 cognitive evoked potentials, especially the amplitude and latency at the Pz electrode site. MATERIAL/METHODS: The P300 parameters of perpetrators of various types of criminal offences and those of a control group matched for age, gender, and educational status were compared (N=80). There were 20 subjects with impulsively aggressive delinquent behavior. The observed parameters were compared with the neuropsychophysiological correlates of a group of 20 subjects with deliberately (i.e. non-impulsive) violent behavior, a group of 20 delinquents sentenced for property crimes (theft), and 20 non-delinquent non-impulsive nonviolent persons. To differentiate these groups, Eysenck's IVE questionnaire and a structured interview according to DSM IV criteria conducted by a certified forensic psychiatrist were used. RESULTS: The results showed a significantly lower P300 wave amplitude in the impulsively aggressive individuals than in the other groups. No significant differences were found in terms of latency. The results confirm the results of previous studies. CONCLUSIONS: The results suggest the possibility of a neuropsychophysiological correlate of impulsively aggressive individuals behaving in a socially dangerous way. This opens a discussion on the subject of expert evaluation of criminal acts within the context of "uncontrolled affect".

P300 wave: a comparative study of impulsive aggressive criminals.

Event-Related potentials are a simple non-invasive neurophysiological method enabling to comprehend certain aspects of the cognitive processing of information in humans. The best-known component of Event-Related Potentials is the so-called P3 wave. Alterations in the parameters of P300 wave have been discovered in certain personality disorders and in persons with impulsively aggressive behaviour. The purpose of this study is to investigate the changes of these parameters, especially an amplitude and latency in the place of Pz electrode. We examined 15 persons with the impulsive aggressive behaviour and compared them to a population comparable of normal age, gender and approximate degree of education. We used P300 auditory and a neuropsychological Eysenck IVE battery. The results showed that significantly lower amplitudes had been found in the aggressive impulsive subjects as compared to the control group. No statistically significant differences have been discovered in the latency. These results seem to confirm previous studies.

BioDat--Web-based system for storing and analyzing 1D signals.

BioDat is a software tool that simplifies routine recording, storing and analyzing technical and biological 1D signals. The basic features of the BioDat software are: database format based on PhysioNet, a shared database of signals running in network environment accessible for users with permissions, importing and/or exporting data from and/or to different formats (d-file, EDF, ASCII, Matlab), accessing the database through HTTP(S) and ordinary web browsers. The application is written in Java and runs both standalone and as installation-free Java applet.

Statistical analysis of QT/RR hysteresis in healthy horses.

The paper describes experiments and their results that offered an insight to relationship between RR and QT intervals in equine ECG signals recorded under various conditions. In contrast to human heart in a great number of cases the QT intervals prolonged with a heart rate acceleration. Peak-to-peak differences between maximum and minimum RR intervals during the excitation response in non-standard responses were twice as smaller as in standard responses and the lengths of QT intervals were significantly longer in the non-standard records. This fact means that the electrical processes in equine heart ventricles must be controlled by different mechanisms than in human heart.