Electrophysiological correlates of in vivo and virtual reality exposure therapy in spider phobia

Analyzing EEG patterns in young adults exposed to different acrophobia levels: a VR study

Introduction

The primary objective of this research is to examine acrophobia, a widely prevalent and highly severe phobia characterized by an overwhelming dread of heights, which has a substantial impact on a significant proportion of individuals worldwide. The objective of our study was to develop a real-time and precise instrument for evaluating levels of acrophobia by utilizing electroencephalogram (EEG) signals.

Methods

EEG data was gathered from a sample of 18 individuals diagnosed with acrophobia. Subsequently, a range of classifiers, namely Support Vector Classifier (SVC), K-nearest Neighbors (KNN), Random Forest (RF), Decision Tree (DT), Adaboost, Linear Discriminant Analysis (LDA), Convolutional Neural Network (CNN), and Artificial Neural Network (ANN), were employed in the analysis. These methodologies encompass both machine learning (ML) and deep learning (DL) techniques.

Results

The Convolutional Neural Network (CNN) and Artificial Neural Network (ANN) models demonstrated notable efficacy. The Convolutional Neural Network (CNN) model demonstrated a training accuracy of 96% and a testing accuracy of 99%, whereas the Artificial Neural Network (ANN) model attained a training accuracy of 96% and a testing accuracy of 97%. The findings of this study highlight the effectiveness of the proposed methodology in accurately categorizing real-time degrees of acrophobia using EEG data. Further investigation using correlation matrices for each level of acrophobia showed substantial EEG frequency band connections. Beta and Gamma mean values correlated strongly, suggesting cognitive arousal and acrophobic involvement could synchronize activity. Beta and Gamma activity correlated strongly with acrophobia, especially at higher levels.

Discussion

The results underscore the promise of this innovative approach as a dependable and sophisticated method for evaluating acrophobia. This methodology has the potential to make a substantial contribution toward the comprehension and assessment of acrophobia, hence facilitating the development of more individualized and efficacious therapeutic interventions.

The impact of fear and psychopathological symptoms on neural responses to naturalistic stimuli in adolescents

The presentation of real-world images can swiftly engage processing mechanisms within specific brain regions and neural pathways. In this study, we explore the effects of fear and psychopathological symptoms on neural processing of realistic stimuli during a free viewing naturalistic task in a sample of adolescents (11-16y). Thirty-one participants performed an experimental task consisting of the visualization of animal pictures according to three conditions - Snakes, Spiders, and Dogs - during EEG recordings. Dimensions of fear and psychopathological symptoms were previously assessed through The Fear Survey Schedule for Children- Revised and the Brief Symptom Inventory. Earlier and later visual processing was analyzed through ERP components' peak amplitudes. The results show a robust effect of psychopathology-related dimensions in the visual processing of naturalistic images, suggesting an increase of neural activity at later stages of visual processing (at the N200 time window) in symptomatic adolescents, corroborating the role of psychopathological symptoms in modulating neural responses to naturalistic images, and also guiding clinicians by providing additional data on how symptomatic adolescents perceive and process reality.