Dense attention network identifies EEG abnormalities during working memory performance of patients with schizophrenia

Perellón Alfonso, Ruben (author), Oblak, Aleš (author), Kuclar, Matija (author), Škrlj, Blaž (author), Škodlar, Borut (author), Pregelj, Peter (author), Repovš, Grega (author), Bon, Jurij (author)

Introduction: Patients with schizophrenia typically exhibit deficits in working memory (WM) associated with abnormalities in brain activity. Alterations in the encoding, maintenance and retrieval phases of sequential WM tasks are well established. However, due to the heterogeneity of symptoms and complexity of its neurophysiological underpinnings, differential diagnosis remains a challenge. We conducted an electroencephalographic (EEG) study during a visual WM task in fifteen schizophrenia patients and fifteen healthy controls. We hypothesized that EEG abnormalities during the task could be identified, and patients successfully classified by an interpretable machine learning algorithm. Methods: We tested a custom dense attention network (DAN) machine learning model to discriminate patients from control subjects and compared its performance with simpler and more commonly used machine learning models. Additionally, we analyzed behavioral performance, event-related EEG potentials, and time-frequency representations of the evoked responses to further characterize abnormalities in patients during WM. Results: The DAN model was significantly accurate in discriminating patients from healthy controls, ACC = 0.69, SD = 0.05. There were no significant differences between groups, conditions, or their interaction in behavioral performance or event-related potentials. However, patients showed significantly lower alpha suppression in the task preparation, memory encoding, maintenance, and retrieval phases F(1,28) = 5.93, p = 0.022, η2 = 0.149. Further analysis revealed that the two highest peaks in the attention value vector of the DAN model overlapped in time with the preparation and memory retrieval phases, as well as with two of the four significant time-frequency ROIs. Discussion: These results highlight the potential utility of interpretable machine learning algorithms as an aid in diagnosis of schizophrenia and other psychiatric disorders presenting oscillatory abnormalities.

• Language: English
• Keywords: schizophrenia, working memory, contralateral delay negativity, electroencephalography EEG, dense attention network DAN
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FF - Faculty of Arts; MF - Faculty of Medicine
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 12 str.
• Numbering: Vol. 14, art. 1205119
• PID: 20.500.12556/RUL-153575
• UDC: 159.91:616.895.8
• ISSN on article: 1664-0640
• DOI: 10.3389/fpsyt.2023.1205119
• COBISS.SI-ID: 166182915
• Publication date in RUL: 16.01.2024

Record is a part of a journal

• Title: Frontiers in psychiatry
• Shortened title: Front. psychiatry
• Publisher: Frontiers Research Foundation
• ISSN: 1664-0640
• COBISS.SI-ID: 54153314

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: shizofrenija, delovni spomin, elektroencefalografija EEG, kontralateralna negativnost, gosto pozornostno omrežje