Advancing the neuroelectrophysiological understanding of attentional switching dysfunction in major depressive disorder

Table 2 Key event-related potential components implicated in attentional and emotional processing dysfunction in major depressive disorder

ERP component	Typical latency	Functional/cognitive significance	Typical finding in MDD	Postulated implication in attentional switching
P100/N170	80-170 ms	Early sensory processing/structural encoding of faces.	Often intact or even enhanced for emotional faces	Suggests basic perceptual encoding is not the primary deficit. May feed heightened signal to later stages
P200	150-250 ms	Early attentional engagement, initial stimulus evaluation, and categorization	Reduced amplitude, especially for negative emotional stimuli	Indicates impaired early filtering and resource allocation to task-relevant or emotional features during a switch
N200	200-350 ms	Conflict monitoring, response inhibition	Findings mixed; may be enhanced in contexts of high conflict	Could relate to increased conflict detection during switching, especially when inhibiting a pre-potent response
P300	300-500 ms	Context updating, attention allocation, and memory processing	Robustly reduced amplitude across many paradigms	Reflects broader deficits in updating mental representations and allocating resources after a task switch
LPP	400-1000 ms	Sustained attention, elaborative processing, and motivational significance of stimuli	Reduced amplitude, particularly for positive and sometimes negative stimuli	Indicates failure to maintain focused cognitive resources on task-relevant or emotional information over time
ERN	50-100 ms	Early, automatic error detection	Often enhanced amplitude	Suggests hyper-vigilant performance monitoring, which may be maladaptive and contribute to rumination

ERN: Error-related negativity; ms: Millisecond; ERP: Event-related potential; MDD: Major depressive disorder; LPP: Late positive potential.