Auditory equiprobable NoGo P3: A single-trial latency-adjusted ERP analysis.

Area of Science:

• Cognitive Neuroscience
• Psychophysiology
• Neuroimaging

Background:

• The NoGo P3 event-related potential (ERP) component's role in response inhibition is debated, particularly in equiprobable Go/NoGo tasks.
• Averaging latency-variable ERP components may distort findings related to the auditory NoGo P3 (or P3a).

Purpose of the Study:

• To investigate the relationship between the NoGo P3 component and inhibitory demands by controlling for latency jitter.
• To identify the neuronal sources of the NoGo P3 across trials using a novel latency adjustment procedure.
• To assess the impact of latency variability on ERP measures and their source localization.

Main Methods:

• A novel procedure was used to control NoGo P3 latency jitter, enabling single-trial P3 quantification in 126 healthy young adults.
• Principal components analysis was employed for P3 quantification.
• Inhibitory demands and performance were measured using the Lateralised Readiness Potential and error rates. Source localization was performed using eLORETA.

Main Results:

• The latency-adjusted P3 (LA-P3) showed an inconsequential relationship with inhibitory demands.
• Cortical sources for LA-P3 were identified in the premotor, prefrontal cortices, cingulate, and precuneus.
• The stimulus-locked P3 (SL-P3), affected by latency jitter, was smaller than LA-P3 and not related to inhibitory demands or performance.

Conclusions:

• The NoGo P3 component does not reliably index response inhibition in auditory equiprobable tasks.
• Findings support a neuroinhibition account, linking NoGo P3 to attentional processes rather than response inhibition.
• Latency-adjustment of ERPs is crucial for accurate measurement and source localization, mitigating 'blurring effects'.