Neural mechanisms and circuit foundations of conscious and unconscious dysfunction in schizophrenia

Table 1 Core paradigms used to study conscious and unconscious processing in schizophrenia

Ref.	Paradigm/method	Processing level emphasized	Main use in the review	Main limitation
[10,28,42,43,48]	Visual masking/object substitution	Conscious access threshold; subliminal processing	Distinguishes impaired reportable perception from preserved masked processing in selected paradigms	Sensitive to visual deficits, attention, and task design
[8,10,15]	Attentional amplification paradigms	Top-down contribution to conscious access	Used to discuss reduced amplification and elevated access threshold	Interpretation depends on task demands
[16,42]	Semantic/affective priming	Subliminal or implicit processing	Used to discuss preserved unconscious semantic or affective processing in specific conditions	Does not generalize to all unconscious or preattentive functions
[31]	Change blindness/implicit detection	Explicit report vs covert sensitivity	Used to discuss dissociation of explicit and implicit responses	Often behaviorally indirect
[1,11,21,26,29,38,70]	ERP measures (P50, MMN, P3/P3b, error-related signals)	Preattentive filtering, deviance detection, conscious access, performance monitoring	Used to relate physiological signatures to conscious and unconscious processing	ERP components do not map one to one onto single cognitive operations
[60,76,83,95]	Resting-state fMRI	Intrinsic large-scale organization	Used to discuss baseline network organization and unconscious neural dynamics	Weak specificity for individual cognitive operations
[22,40,83]	Structural connectivity imaging	White matter and network organization	Used to relate structural connectivity to access-related deficits	Relatively indirect for task specific mechanisms
[23,34,54,67,103]	Metacognitive tasks and insight measures	Confidence calibration, self-evaluation, insight	Used to discuss explicit self-monitoring abnormalities	Must control first order performance

ERP: Event-related potential; fMRI: Functional magnetic resonance imaging; MMN: Mismatch negativity; P3/P3b: P3 (P300)/P3b late positive event-related potential component (often linked to conscious access); P50: P50 auditory evoked potential component used in sensory gating paradigms.