Abnormal EEG complexity in patients with schizophrenia and depression

Area of Science:

• Neuroscience
• Computational Psychiatry
• Biomedical Engineering

Background:

• Cortical information processing disturbances in schizophrenia affect cognitive task performance, observable via electroencephalogram (EEG) abnormalities.
• Quantitative EEG analysis may offer insights into these cortical disturbances, but its efficacy remains under investigation.

Purpose of the Study:

• To characterize EEG disturbances using Lempel-Ziv complexity (LZC) in individuals with schizophrenia at rest and during mental arithmetic.
• To compare LZC findings in schizophrenia patients with those in depression patients and healthy controls.

Main Methods:

• EEG data were collected from 62 schizophrenia patients, 48 depression patients, and 26 healthy controls.
• EEG signals were analyzed using LZC and conventional spectral methods under resting (eyes closed) and mental arithmetic conditions.

Main Results:

• LZC decreased during mental arithmetic across all groups.
• Schizophrenia and depression groups exhibited higher LZC than controls.
• Schizophrenia patients showed lower LZC than depression patients during both rest and mental arithmetic.

Conclusions:

• LZC is more sensitive than spectral analysis for detecting EEG signal changes.
• LZC is associated with task attention and cognitive adaptation, proving useful for studying cortical processing in schizophrenia and depression.
• LZC analysis is a valuable tool for future research into the pathophysiology of schizophrenia and depression.