ABSTRACT
BACKGROUND: Cognitive models propose that attentional dysregulation, including an attentional bias towards threat, is one of the factors through which chronic pain and post-traumatic stress symptoms (PTSS) maintain and exacerbate one another. The current investigation assessed the attentional bias for painful facial expressions and its relationship with PTSS, using both traditional and variability-based attentional bias measures, among veterans with chronic pain and PTSS and controls. METHOD: Fifty-four veterans with chronic pain and 30 age/education-matched controls participated in this investigation. Participants completed a self-report measure of PTSS and a modified version of the dot-probe task with painful, happy, and neutral facial expressions. Attention was assessed using both traditional and variability-based reaction time measures of attentional bias. RESULTS: Veterans directed attention away from painful facial expressions (i.e., avoidance) relative to both the control group (between-subject effect) and relative to neutral faces (within-subject effect). Veterans also showed significantly elevated attentional bias variability for both happy and painful facial expressions compared to controls. Attentional bias variability for happy and painful facial expressions was correlated with PTSS among all participants. CONCLUSION: Veterans with chronic pain and PTSS avoided pain-related stimuli and displayed an overall attentional dysregulation for emotional facial expressions. Avoidance of pain cues may be a coping strategy that these individuals develop under stressful conditions. Implications, limitations, and directions for future research are discussed.
Subject(s)
Attentional Bias , Chronic Pain/physiopathology , Chronic Pain/psychology , Stress Disorders, Post-Traumatic/physiopathology , Stress Disorders, Post-Traumatic/psychology , Stress, Psychological , Veterans/psychology , Adolescent , Adult , Aged , Anxiety/complications , Anxiety/physiopathology , Anxiety/psychology , Case-Control Studies , Chronic Pain/complications , Cues , Emotions , Facial Expression , Humans , Male , Middle Aged , Reaction Time , Self Report , Stress Disorders, Post-Traumatic/complications , Stress, Psychological/complications , Stress, Psychological/physiopathology , Stress, Psychological/psychology , Young AdultABSTRACT
Thick films of calcinated and non calcinated nanobioglass (NBG)-titania composite coatings were prepared on stainless steel substrates by alkoxide sol-gel process. Dip-coating method was used for the films preparation. The morphology, structure and composition of the nano composite films were evaluated using environmental scanning electron microscope, X-ray diffraction and Fourier transform infrared spectroscope. The SEM investigation results showed that prepared thick NBG-titania films are smooth and free of macrocracking, fracture or flaking. The grain size of these films was uniform and nano scale (50-60 nm) which confirmed with TEM. Also FTIR confirmed the presence of Si-O-Si bands on the calcinated NBG-titania films. The hardness of the prepared films (TiO(2)-calcinated NBG and TiO(2)-Non calcinated NBG) was compared by using micro hardness test method. The results verified that the presence of calcinated NBG particles in NBG-titania composite enhanced gradually the mechanical data of the prepared films. The in vitro bioactivity of these films was discussed based on the analysis of the variations of Ca and P concentrations in the simulated body fluid (SBF) and their surface morphologies against immersion time. Surface morphology and Si-O-Si bands were found to be of great importance with respect to the bioactivity of the studied films. The results showed that calcinated NBG-titania films have better bioactivity than non calcinated NBG-titania films.
