Analysis of Effective Connectivity Strength in Children with Attention Deficit Hyperactivity Disorder Using Phase
Ali Ekhlasi1, Ali Motie Nasrabadi2, Mohammad Reza Mohammadi3
1Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Insights
Attention deficit hyperactivity disorder (ADHD) shows altered brain network connectivity. Healthy children exhibit stronger prefrontal brain network connectivity, while ADHD patients display enhanced central region connectivity during attention tasks.
Area of Science:
- Neuroscience
- Computational Neuroscience
- Developmental Neuroscience
Background:
- Attention deficit hyperactivity disorder (ADHD) is a prevalent neurodevelopmental disorder.
- Understanding brain network differences in ADHD is crucial for diagnosis and treatment.
- Electroencephalography (EEG) offers a valuable tool for investigating brain activity and connectivity.
Purpose of the Study:
- To investigate differences in brain network connectivity between children with ADHD and healthy controls during an attention task.
- To analyze the strength and direction of neural connections using Phase Transfer Entropy (PTE).
- To identify specific brain regions and electrodes showing distinct connectivity patterns in ADHD.
Main Methods:
- Constructed weighted directed graphs from EEG signals of 61 children with ADHD and 60 healthy children.
- Utilized Phase Transfer Entropy (PTE) to measure directed connectivity between 19 EEG electrodes across five frequency bands (delta, theta, alpha, beta, gamma).
- Applied permutation statistical tests to compare connectivity strength after graph sparsification.
Main Results:
- Healthy children demonstrated stronger inter-regional connectivity in prefrontal brain areas compared to the ADHD group.
- Children with ADHD exhibited higher inter-regional connectivity strength in central brain regions.
- The Fp1 electrode (left prefrontal) showed stronger signal transmission roles in healthy individuals.
Conclusions:
- The study reveals significant differences in brain network connectivity between children with and without ADHD during attention tasks.
- Findings highlight altered patterns of signal transmission, particularly in prefrontal and central brain regions.
- This research provides novel insights into the neurophysiological underpinnings of ADHD.
Abstract:
Objective: This study aimed to investigate differences in brain networks between healthy children and children with attention deficit hyperactivity disorder (ADHD) during an attention test. Method : To fulfill this, we constructed weighted directed graphs based on Electroencephalography (EEG) signals of 61 children with ADHD and 60 healthy children with the same age. Nodes of graphs were 19 EEG electrodes, and the edges were phase transfer entropy (PTE) between each pair of electrodes. PTE is a measure for directed connectivity that determines the effective relationship between signals in linear and nonlinear coupling. Connectivity graphs of each sample were constructed using PTE in the five frequency bands as follows: delta, theta, alpha, beta, and gamma. To investigate the differences in connectivity strength of each node after the sparsification process with two values (0.5 and 0.25), the permutation statistical test was used with the statistical significance level of p<0.01. Results: The results indicate stronger inter-regional connectivity in the prefrontal brain regions of the control group compared to the ADHD group. However, the strength of inter-regional connectivity in the central regions of the ADHD group was higher. A comparison of the prefrontal regions between the two groups revealed that the areas of the Fp1 electrode (left prefrontal) in healthy individuals play stronger transmission roles. Conclusion: Our research can provide new insights into the strength and direction of connectivity in ADHD and healthy individuals during an attention task.
