Many ways to forget – Neurophysiology of directed forgetting mechanisms in schizophrenia

Abstract

Numerous studies have shown dysfunctional mechanism of interaction between bottom-up emotional and top-down cognitive processes in persons with schizophrenia (SCZ). During the emotional directed forgetting (DF) paradigm participants have to apply volitional mechanisms to resist automatic emotional enhancement of the memory. Here we sought to compare mechanisms underlying emotional DF in SCZ and in healthy persons (HC). Eighteen SCZ and eighteen HC completed a DF paradigm with neutral and negative pictures. EEG was recorded during study and test phase of the task. We analyzed both the behavioral outcomes and event-related potential components, indicating emotional enhancement of memory (Late Positive Potential elicited by pictures) and DF strategies (N2/P3 elicited by forget/remember cues during study-phase; “old/new” and “reversed old/new” effects during test-phase of the task). Directed forgetting effects and emotional enhancement of memory were observed in both groups, even despite overall lower recognition rates in SCZ. Furthermore, cue presentation elicited similar pattern of N2/P3s in SCZ and in HC. However, “reversed old/new” effect was observed only in HC for negative stimuli. Patients may show similar reaction to affective stimuli as healthy controls during the emotional DF task. However, further investigation is needed to elicit the specific mechanisms underlying the DF strategies in SCZ.