Nonlinear relations between post‐traumatic stress symptoms and electrocortical reactivity during emotional face processing in combat‐exposed veterans

Abstract

Combat‐related post‐traumatic stress symptoms (PTSS) are prevalent among recently deployed veterans, making identification of biomarkers of PTSS in this population a public health priority. Given the link between threat processing neurobiology and PTSS, the threat‐related late positive potential (LPP), an ERP reflective of attentional processing sensitive to emotion and its regulation, may have utility as a cost‐effective biomarker. Existing PTSS/threat‐related LPP findings are mixed, possibly due to variability in PTSS across samples, but this has never been explicitly tested. To address this gap, LPP amplitudes to angry, fearful, and happy emotional face stimuli were recorded among 81 combat‐exposed veterans at a VA hospital. A quadratic relationship between self‐reported PTSS and LPP amplitude modulation by angry faces emerged such that greater PTSS was related to a decreased LPP response to angry faces among veterans with subthreshold PTSD and an enhanced LPP response to angry faces among veterans with probable PTSD. These results suggest that prior mixed findings may be due to variability in PTSS severity. In addition, exploratory moderation analysis revealed that PTSS was positively associated with late LPP modulation for veterans reporting low cognitive reappraisal use and negatively associated with late LPP modulation for veterans reporting high cognitive reappraisal use. All results were specific to the 1,000–3,000 ms LPP time window. Thus, the functional nature of LPP modulation by direct threat cues may depend upon PTSS severity and/or related variables (e.g., cognitive reappraisal utilization).

Evaluating the internal consistency of subtraction‐based and residualized difference scores: Considerations for psychometric reliability analyses of event‐related potentials

“…In many areas of neuroscience research, including ERP studies, a common approach for calculating difference scores is to subtract activity during one condition ( X , the subtrahend) from activity during another condition ( Y , the minuend; Y − X ). Another approach increasing in popularity is a residualized difference score (e.g., Crane et al., 2021; Hanna et al., 2020; Klawohn et al., 2020; Macatee et al., 2020; Meyer et al., 2017; Muir et al., 2020; Sandre et al., 2020; Schroder et al., 2020; Suor et al, in press). A residualized difference score is the difference between the actual score ( Y ) and predicted score () using a linear regression equation (), wherein Y scores are regressed on X .…”

Posttraumatic stress symptom severity is associated with impaired processing of emotional faces in a large international sample

“…Furthermore, using EEG, one study found that late positive potential (LPP), an event-related potential that reflects facilitated attention toward emotional stimuli, was related to PTSS with regard to viewing angry faces specifically (DiGangi et al, 2017), suggesting that individuals with PTSD actively avoid looking at angry faces. These results were replicated and clarified by another study, which showed that the more severe PTSS, the greater the LPP effect (Macatee et al, 2020). In a recent study examining childhood maltreatment and PTSD and interpretations of neutral facial expressions, participants with PTSD did not perform any differently than control groups, but higher levels of childhood emotional and sexual abuse, as well as physical neglect, were linked to a more negative interpretation of neutral facial expressions (Pflatz et al, 2019).…”

Neurophysiological patterns associated with blunted emotional face processing and withdrawal tendencies in young children exposed to intimate partner violence

“…Other studies have contradictorily observed blunted LPP amplitudes to threatening stimuli, relative to nonthreatening stimuli, in adults with combat exposure (Digangi et al., 2017; MacNamara et al., 2013 ). Still others find a quadratic pattern, where those with the lowest and highest PTSD symptoms exhibit larger LPPs to angry faces, but those with more moderate symptom levels showed blunting (Macatee et al., 2020).…”