Exploring the Effect of Negative Mood on Working Memory Subprocesses: An Event-Related Potential Study.

Working memory (WM) regulates information flow through gate mechanisms, consisting of four subprocesses: gate opening, gate closing, updating, and substitution. However, their neural mechanisms remain underexplored. While emotion-cognition interactions are well studied, the effects of negative mood on these subprocesses are unclear. This study examines their neural mechanisms using event-related potentials (ERPs) and investigates negative mood influence. Thirty-seven participants completed a cue-version reference-back task after mood induction (negative or neutral) across two sessions, with behavioral and EEG data recorded. Mood changes were assessed via the Positive and Negative Affect Schedule (PANAS) before and after the experiment. A total of 32 participants were included in the final analysis. The behavioral results showed that all WM subprocess (gate opening, gate closing, updating, and substitution) costs were observed in reaction time (RT), but only substitution costs were evident in error rate (ER). Negative mood only reduced substitution costs in RT. The ERP results revealed that gate opening was activated during both the cue phase (550-1000 ms at frontal and central areas) and the probe phase (670-920 ms at central and parietal areas), whereas no gate closing costs were observed in neural activity. Updating was activated at central, parietal, and occipital areas (630-1000 ms post-probe), and substitution was linked to parietal areas (710-980 ms post-probe). Negative mood specifically reduced gate opening costs during the probe phase. This study confirms the existence of four WM subprocesses, and suggests that negative mood influences gate opening and substitution subprocess.