The Detection Of Emoticon-related ERP And The Value Of Forensic Medicine

【Background】Traumatic brain injury is an important factor in the mental disorders,mood disorders is the most frequently occurring psychiatric symptoms of patients withmental impairment. In forensic expertise, generally considered intellectual impairment,but forgotten or ignored the emotions disorder, while the injured persons in order to obtainmore compensation, they tend to exaggerate their symptoms and make the tools of theexisting scale score lack of reliability. Exploring the objective quantitative indicatorswhich can reflect the degree of mood disorders due to traumatic brain injury has greatvalue. Event-related potentials (ERP) as the objective indicators of the assessment ofbrain electrical activity, and less susceptible to the subjects. Reports have been shown thatsome of the ERP components are related to emotions, such as N2,P3.The current study isto explore the mechanisms of emotional processing, how to use the emotion-related ERPobjective assessment of emotional disorders and its application in forensic expertise to bestudied.【Objectives】To prepare ERP paradigm which can suit patients with brain trauma usingthe pictures of different emotions by testing healthy volunteers and patients with braintrauma and provide objective indicators of electro-physiological testing for forensicexpertise of emotional disorders by observing the emotion-related ERP waveformcharacteristics, composition, and analyzing the correlation with the SCL-90.【Methods】Emotion pictures of identifying ERP testing sequence were presented byNeuroscan ERP instrument. the emotion pictures of calm, pleasure and angry as well asthe control pictures were presented randomly to the testers including20normal volunteers(10males,10females) and22patients with traumatic brain injury (19males,3females).Testers were tested by ERP detection and the SCL-90test. Two groups of testers anddifferences characteristic components of ERP were compared, and the correlation withSCL-90were analyzed【Results】(1) Through the emotion pictures stimulus, normal volunteers of threeemotional pictures can lead to N1, P2, N2, P3. There was little difference between the pictures of different emotions. The P2, N2of the blank picture led insufficient, and the P3led flat. The different between male and female’s ERP wave was little, but male’svolatility overall slightly higher than the female.(2) Traumatic brain injury involving inindentifying emotion pictures stimulus of ERP can also lead to N1, P2, N2, P3, comparedwith the normal group, N2was longer in latency, P3was lower in amplitude. With calmpicture stimulate, the amplitude of N2was higher than the normal group (P<0.05), thelatency of N2and the amplitude of P3was longer and lower compared with the normalgroup (P<0.01). With pleasant picture stimulate, the latency of N2was longer than thenormal group (P<0.05), and the amplitude of P3was lower compared with the normalgroup (P<0.01). With angry picture stimulate, the amplitude and latency of N2was higherand longer than the normal group (P<0.05), the amplitude of P3was lower compared withthe normal group (P<0.01).(3) From the brain electrical activity mapping, the normalgroup was mainly activate temporal-parietal in completing the stimulation task, but thetrauma group was more evident in the top of the occipital lobe. The activity intensity oftraumatic group was weak, the scope of activity was reduced.(4) The scores of SCL-90were higher in traumatic group than normal group (P<0.01). The SCL-90scores andface-related ERP were not significantly related. Only some factor scores were positivelycorrelated with the ERP components(r=0.43～0.53, P<0.05).【Conclusion】Both normal group and traumatic using emotion pictures stimulation canlead to N1,P2,N2,P3composition. The difference between the ERP waveform of differentpicture stimuli was not obvious. In traumatic group, compared with normal group, N2waslonger in latency, higher in amplitude, P3was lower in amplitude, indicating the brainfunction was damaged. From the brain electrical activity mapping, the active portion waschanged, the activity intensity of traumatic group was weak, the scope of activity wasreduced. The scores of SCL-90were higher in traumatic group then normal group, but thecorrelation of them was not closely, only the individual prompt it. N2,P3can be used as anelectrophysiological reference for objective assessment of the emotion disorder in forensicexpertise.