Single-Trial Mechanisms Underlying Changes in Averaged P300 ERP Amplitude and Latency in Military Service Members After Combat Deployment

Amy Trongnetrpunya; Paul Rapp; Chao Wang; David Darmon; Michelle E Costanzo; Dominic E Nathan; Michael J Roy; Christopher J Cellucci; David Keyser

doi:10.3389/fnhum.2019.00377

Single-Trial Mechanisms Underlying Changes in Averaged P300 ERP Amplitude and Latency in Military Service Members After Combat Deployment

Front Hum Neurosci. 2019 Oct 25:13:377. doi: 10.3389/fnhum.2019.00377. eCollection 2019.

Authors

Amy Trongnetrpunya¹, Paul Rapp², Chao Wang¹, David Darmon³, Michelle E Costanzo⁴, Dominic E Nathan^{5

6}, Michael J Roy⁴, Christopher J Cellucci⁷, David Keyser²

Affiliations

¹ Henry M. Jackson Foundation, Department of Military and Emergency Medicine, Uniformed Services University, Bethesda, MD, United States.
² Department of Military and Emergency Medicine, Uniformed Services University, Bethesda, MD, United States.
³ Department of Mathematics, Monmouth University, West Long Branch, NJ, United States.
⁴ Department of Medicine, Uniformed Services University, Bethesda, MD, United States.
⁵ Henry M. Jackson Foundation, Center for Neuroscience and Regenerative Medicine, Uniformed Services University, Bethesda, MD, United States.
⁶ Graduate School of Nursing, Uniformed Services University, Bethesda, MD, United States.
⁷ Aquinas LLC, Berwyn, PA, United States.

Abstract

Attenuation in P300 amplitude has been characterized in a wide range of neurological and psychiatric disorders such as dementia, schizophrenia, and posttraumatic stress disorder (PTSD). However, it is unclear whether the attenuation observed in the averaged event-related potential (ERP) is due to the reduction of neural resources available for cognitive processing, the decreased consistency of cognitive resource allocation, or the increased instability of cognitive processing speed. In this study, we investigated this problem by estimating single-trial P300 amplitude and latency using a modified Woody filter and examined the relation between amplitudes and latencies from the single-trial level to the averaged ERP level. ERPs were recorded from 30 military service members returning from combat deployment at two time points separated by 6 or 12 months. A conventional visual oddball task was used to elicit P300. We observed that the extent of changes in the within-subject average P300 amplitude over time was significantly correlated with the amount of change in three single-trial measures: (1) the latency variance of the single-trial P300 (r = -0.440, p = 0.0102); (2) the percentage of P300-absent trials (r = -0.488, p = 0.005); and (3) the consistent variation of the single-trial amplitude (r = 0.571, p = 0.0022). These findings suggest that there are multiple underlying mechanisms on the single-trial level that contribute to the changes in amplitudes seen at the averaged ERP level. The changes between the first and second assessments were quantified with the intraclass correlation coefficient, the standard error of measurement and the minimal detectable difference. The unique population, the small sample size and the large fraction of participants lost to follow up precludes generalizations of these measures of change to other populations.

Keywords: ERP; P300; PTSD; combat trauma; single-trial.