PhD Scientific Days 2021

Budapest, 7-8 July 2021

MH_I_P: Mental Health Sciences I. Posters

Distractor Filtering and Its Electrophysiological Correlates in Schizophrenia

Melinda Becske1, Csilla Marosi1, Hajnalka Molnár1, Zsuzsanna Fodor1, László Tombor1, Gábor Csukly1
1 Department of Psychiatry and Psychotherapy, Semmelweis University, Budapest

Text of the abstract

Introduction: Patients with schizophrenia are characterized by compromised working memory (WM) performance and increased distractibility. Theta synchronization (especially over the frontal midline areas) is related to cognitive control and executive processes during WM encoding and retention. Alpha event-related desynchronization (ERD) is associated with information processing and attention.
Aims: Our objective was to gain more insight into the nature of attentional distractibility in schizophrenia.
Method: Participants (35 patients and 39 matched controls) performed a modified Sternberg WM task, containing salient and non-salient distractor items in the retention period. A high-density 128 channel EEG was recorded during the task. Theta (4-7 Hz, 350-550 ms) and fast alpha (10-13 Hz, 500-700 ms) event-related spectral perturbation (ERSP) were analyzed during the retention and encoding period.
Results: Patients with schizophrenia showed worse WM performance and increased attentional distractibility in terms of lower hit rates (p < 0.0001) and increased distractor-related commission errors (p < 0.0001) compared to healthy controls. Theta synchronization was modulated by condition (learning vs. distractor) in both groups but it was modulated by salience only in controls (salient > non-salient, p[patients] = 0.95; p[controls] < 0.001). Furthermore, salience of distractors modulated less the fast alpha ERD in patients (salient > non-salient, Cohen's d[patients] = 0.9; Cohen's d[controls] = 1.6).
Conclusion: Our results suggest that patients with schizophrenia process salient and non-salient distracting information less efficiently and show weaker cognitive control compared to controls. These differences may partly account for diminished WM performance and increased distractibility in schizophrenia.
Our work was supported by the following grants:
Hungarian Research Found - OTKA PD 115837;
Bolyai Research Fellowship Program of the Hungarian Academy of Sciences;
ÚNKP - New National Excellence Program of the Ministry of Human Capacities;
Higher Education Institutional Excellence Programme of the Ministry of Human Capacities in Hungary, within the framework of the Neurology thematic programme of Semmelweis University.

University and Doctoral School

Semmelweis University, Doctoral School of Mental Health Sciences