Advances in electrophysiological research on emotional and reward processing in major depressive disorder

Table 1 Event-related potential components indexing emotional and reward processing in major depressive disorder

Domain	ERP component	Time window scalp (typical)	Indexed function	Typical MDD abnormality	Putative neural circuits	Intervention/translation links
Emotion	P1	< 200 milliseconds; occipital (early visual)	Initial perceptual encoding & attentional allocation to emotional cues	Reduced amplitude; blunted early attention to positive cues; sometimes negativity bias in high negative affectivity	Early visual cortex to ventral visual stream; modulation by PFC/ACC-limbic network (PFC/ACC ↔ amygdala/hippocampus)	CBT and prefrontal neuromodulation may enhance top-down control and normalize early attentional allocation
Emotion	N170	Approximately 140-200 milliseconds; occipito-temporal (face-sensitive)	Structural encoding of faces; early facial representation; emotion cue detection	Reduced amplitude to positive faces; possible enhanced responses to threat in subgroups (negativity bias)	Occipito-temporal face network; interaction with amygdala and PFC/ACC during emotional face processing	CBT; neuromodulation (e.g., DLPFC-tDCS) associated with improved emotion recognition/ERP indices
Emotion	P200	Approximately 150-250 milliseconds; fronto-central/centro-parietal (task-dependent)	Early attentional selection; cross-modal integration of emotional information	Reduced amplitude reflecting early-stage impairment in emotional cue detection/attentional allocation	Distributed attentional network; PFC/ACC contributions to selection/integration; limbic modulation	Mechanism-based neuromodulation targeting prefrontal control networks; CBT
Emotion	LPP (emotion)	≥ 300 milliseconds (often 300-600+ milliseconds); centro-parietal	Sustained emotional engagement, meaning extraction, affective salience	Attenuated LPP; reduced sustained engagement with emotional/positive stimuli; blunted affective salience	Prefrontal-limbic regulation (DLPFC/vmPFC/ACC ↔ amygdala/hippocampus/insula)	CBT; prefrontal stimulation (tDCS); pharmacological modulation reported to enhance late positive activity
Reward	CNV	Slow negative potential during anticipation (S1-S2/pre-outcome); fronto-central	Motivational preparation & temporal expectancy during reward anticipation	Attenuated CNV, especially for high-value social rewards; associated with poorer performance/engagement	Mesocorticolimbic preparation network (PFC/ACC ↔ striatum/NAc) with motivational drive from VTA	Behavioral activation/social-reward paradigms; circuit-based neuromodulation; translational social-feedback interventions
Reward	SPN	Slow negativity immediately preceding feedback/outcome revelation; often fronto-central (task-dependent)	Informational anticipation (anticipatory attention/motivation toward impending feedback/outcome information)	Emerging evidence of blunted SPN during reward anticipation; suggests reduced anticipatory engagement for reward-related information; needs standardized replication	Expectancy/anticipatory attention networks involving medial/Lateral PFC and ACC; task-dependent insula/parietal contributions; interaction with valuation circuitry	Candidate treatment-sensitive readout for interventions targeting anticipatory reward processing (behavioral activation, prefrontal neuromodulation, social-feedback training)
Reward	RewP (FRN subcomponent)	Approximately 250-500 milliseconds post-feedback; fronto-central	Rapid reward sensitivity/outcome valuation (reward vs non-reward)	Reduced RewP; correlates with anhedonia and motivational deficits; present in MDD and high-risk groups	Mesocorticolimbic reward circuit (VTA to NAc/ventral striatum to vmPFC/OFC/ACC)	Mechanism-based interventions targeting reward circuitry; pharmacological and neuromodulation approaches; potential biomarker of treatment response
Reward	FRN	Approximately 200-350 milliseconds post-feedback; fronto-central	Feedback evaluation/negative prediction error signaling	Altered FRN in social feedback; effects may be stronger for social vs monetary outcomes	ACC-centered monitoring with striatal inputs; interacts with mesocorticolimbic circuitry	Social-feedback interventions (e.g., robot-mediated paradigms) may normalize feedback-related processing
Reward	P3 (reward)	Approximately 300-600 milliseconds; centro-parietal (task-dependent)	Motivational salience allocation & updating of stimulus significance	Attenuated P3 to reward feedback, particularly in social reward tasks	Distributed salience/attention network; PFC/ACC and parietal integration; striatal contribution via motivational salience	Pharmacological/neuromodulation readouts; social-feedback interventions
Reward	LPP (reward feedback)	Late sustained positivity after feedback; centro-parietal	Sustained evaluative processing & affective integration of reward outcomes	Reduced LPP to reward outcomes; together with RewP predicts depression severity via distinct pathways	Mesocorticolimbic valuation with prefrontal integration; interaction with limbic affect systems; LHb anti-reward modulation	Astrocyte-/LHb-targeting strategies (e.g., Kir4.1/CB1R modulation, LHb-DBS in TRD); pharmacological approaches; potential biomarker of treatment effects

ERP: Event-related potential; LPP: Late positive potential; CNV: Contingent negative variation; SPN: Stimulus-preceding negativity; RewP: Reward positivity; FRN: Feedback-related negativity; MDD: Major depressive disorder; PFC: Prefrontal cortex; ACC: Anterior cingulate cortex; DLPFC: Dorsolateral prefrontal cortex; vmPFC: Ventromedial prefrontal cortex; NAc: Nucleus accumbens; VTA: Ventral tegmental area; OFC: Orbitofrontal cortex; LHb: Lateral habenula; CBT: Cognitive-behavioral therapy; tDCS: Transcranial direct current stimulation; CB1R: Cannabinoid type 1 receptor; DBS: Deep brain stimulation; TRD: Treatment-resistant depression.