EEG Power Spectral Density Investigation in Children with ADHD and Matched Controls

1. BackgroundAttention Hyperactivity Disorder (ADHD) is endorsed between 4The difficulty in recognizing the emotions of others leads to an experience of social infertility in the ADHD group. so the recognition of nonverbal symptoms that conveys the feelings of others is important because it helps one to behave in the face of others.2. MethodEEG signals used in this research was recorded from 11 ADHD children based on DSM-IV (7-11 years old) and 17 typically developing ones while performing an emotional face recognition task. After preprocessing, Event Related Potentials (ERPs) of each emotion were calculated by averaging its correspondent epochs that were time locked to the stimulus onset. In the next stage, the Power Spectrum Densities (PSD) of the resultantERPs were calculated using Welch method. (ARNS, 2013, journal of attention disorders). And they were splited into the main EEG signal frequency bands (Alpha, Betta, Theta and Gamma). In the statistical analysis stage, in order to find meaningful differences between two groups (AHDH and Healthy) and four emotions (Angry, Happy, Neutral and sad) , first normality of the data has been verified using the Kolmogorov-simonovmethod (yurtbasi, 2018,journal of attention disorders). Normality of data led us to use parametric tests. Due to three independent variables (disease, emotion and frequency bands) and one dependent variable (PSD), The Two-way ANOVA test was applied.3. Results The results of statistical analysis are divided into three categories: first the differences between the healthy group and the patient without considering the emotion, second the differences between the emotions, regardless of the ADHD or healthy, and third, interaction between disease and emotions. The results indicate that there is no significant difference between the emotions (second category), as well as the interaction ofemotions and diseases (third category). But in the first category, there was a significant difference between the healthy group and the patient group (At a significant level of 5% and mean and PSD average of ADHD subjects was higher than Healthy subjects). The average of P-Values for Alpha, Betta, Theta and Gamma bands are 0.0292, 0.0266, 0.0273 and 0.0216 respectively. In figure1 we see topo-maps showing the differences(P-values) on the head. (The red regions in the images show an increase in the activity of healthy subject than patients).4. Conclusions Although there is no significant difference among various groups of emotions was not achieved which needsfurther investigations but as shown in Figure 1, the most significant difference in all of the frequency bands is observed in the right regions of the forehead. In addition, these differences in the frequency bands of beta and theta are observed in the central and left areas of the head as well. The results showed that ADHD children have a significant increase in their power spectral density in comparison with normal group.