Mechanisms Underlying Unconscious Processing and Their Alterations in Post-traumatic Stress Disorder: Neuroimaging of Zero Monetary Outcomes Contextually Framed as “No Losses” vs. “No Gains”

Abstract

Although unconscious processing is a key element of mental operation, its neural correlates have not been established. Also, clinical observations suggest that unconscious processing may be involved in the pathophysiology of post-traumatic stress disorder (PTSD), but the neurobiological mechanisms underlying such impairments remain unknown. The purpose of the present study was to examine putative mechanisms underlying unconscious processing by healthy participants and to determine whether these mechanisms may be altered in PTSD patients. Twenty patients with PTSD and 27 healthy individuals were administered a validated wheel of fortune-type gambling task during functional magnetic resonance imaging (fMRI). Unconscious processing was elicited using unconscious contextual framing of the zero monetary outcomes as “no loss,” “no gain” or as “neutral.” Brief passive visual processing of the “no loss” vs. “no gain” contrast by healthy participants yielded bilateral frontal-, temporal- and insular cortices and striatal activations. Between-group comparison revealed smaller activity in the left anterior prefrontal-, left dorsolateral prefrontal-, right temporal- and right insular cortices and in bilateral striatum in PTSD patients with the left dorsolateral prefrontal cortex activity been more pronounced in those with greater PTSD severity. These observations implicate frontal-, temporal-, and insular cortices along with the striatum in the putative mechanisms underlying unconscious processing of the monetary outcomes. Additionally, our results support the hypothesis that PTSD is associated with primary cortical and subcortical alterations involved in the above processes and that these alterations may be related to some aspects of PTSD symptomatology.

Association between body mass index and treatment completion in extended-release naltrexone-treated patients with opioid dependence

“…This adjustment impacts the coping strategies that patients employ, which in turn influences their expectations and satisfaction with their body weight outcomes. It is possible that protracted withdrawal and/or food craving up to a new neutral state may not be perceived as aversive ( 65 ) in such reformulated contextual framing ( 66 , 67 ), prompting adherence and eventual recovery ( 37 ).…”

Personalized repetitive transcranial magnetic stimulation (prtms®) for post-traumatic stress disorder (ptsd) in military combat veterans

“…These Veterans often see civilian life as bland, stressful, and unfulfilling and describe themselves as “numb.” They may turn to drugs or alcohol as a means of overcoming this stress and numbing and recreating the highs they felt while in combat. Improved DMN connectivity and functionality attained via PrTMS [ 104 ] may help patients reprocess traumatic memories and develop new cognitive strategies for reframing and responding to stressful situations [ 21 ] and for confronting and recontextualizing traumatic memories and emotions in a safe therapeutic environment [ 105 ].…”

“…To date, most psychophysiology [ [13] , [14] , [15] ] and functional brain imaging PTSD studies [ 16 , 17 ] have focused on conditioned fear [ 18 , 19 ] underlying enhanced- or unsuccessfully extinguished responses to trauma-related cues [ 20 ]. However, our recent research [ 21 ] also links PTSD with aberrations in contextual processing [ 22 , 23 ]. Contextual processing refers to the adaptive way the brain interprets incoming sensory information in the context of environment and prior experiences.…”

“…As such, it involves the processing of multiple sources of information, including sensory input, memories, emotions, and salience, to generate a cohesive and meaningful representation of the current situation [ 24 ]. This activity enables instantaneous and spontaneous decision making in contrast to “slow thinking” [ 25 ] i.e., cost/benefit-informed deliberate and quantitative cognition aimed at profit maximization [ 21 ]. Individuals with PTSD often have difficulty properly integrating sensory information [ [26] , [27] , [28] , [29] , [30] , [31] ], leading to autonomic instability, hyperarousal and hypervigilance in response to environmental stimuli [ 12 ].…”

“…Since by its nature spontaneous and automatic cognition is not readily accessible to self-reports [ 21 ] inquiry into the DMN's role in the PTSD therapeutic outcomes is limited, in part, by a paucity of robust laboratory-based procedures that may measure real time treatment-related adjustments in DMN function. To that end we have developed [ 55 ] a repetitive transcranial magnetic stimulation (rTMS) protocol termed personalized-rTMS (PrTMS) which incorporates the key electroencephalographic measure of DMN activity [ 56 ], the alpha oscillatory rhythm (8–13 Hz).…”