Attentional Bias Modification in Fibromyalgia Patients (ABM) (ABM)

Neural Mechanisms Underlying Attentional Bias Modification in Fibromyalgia Patients: a Double-blind ERP Study

There is a growing interest in the potential benefits of attentional bias modification (ABM) training in chronic pain patients. However, studies examining the effectiveness of ABM programs in fibromyalgia patients have demonstrated inconclusive effects on both behavioral indices and clinical symptoms. Underlying neural dynamics of ABM effects could yield additional insights but remain yet unexplored. Current study, therefore, aimed investigating the effects of ABM training on known neural indicators of attentional bias to pain using electroencephalography (EEG). The goal of this clinical trial is to test the effects of ABM training on known neural indicators of attentional bias to pain using electroencephalography (EEG) in fibromyalgia patients The main question[s] it aims to answer are: Are fibromyalgia patients sensitive to ABM procedures? What are the neural indices associated with ABM procedures? Do ABM procedures transfer of effects on the clinical symptomatology in fibromyalgia patients? Participants will performes five sessions consisting of a modified dot-probe task in which patients were trained to avoid facial pain expressions, whereas in the control group participants will performes five sessions consisting of a standard dot-probe task. Potential ABM training effects will be evaluated by comparing a single pre- and post-treatment session, in which event-related potentials (ERPs) will be recorded in response to three experimental tasks (standard dot-probe, RIR, and visual tasks). Furthermore, patients will fill a series of self-report questionnaires assessing anxiety, depression, pain-related worrying, fear of pain, fatigue and pain status. Researchers will compare two fibromyalgia patients groups that will enrolled and randomly assigned to an ABM training in order to see attentional improvements in the training fibromyalgia group.

ABM training will consist of five sessions over five consecutive days during which patients performed a modified version of the visual dot-probe task. The whole ABM program will include a total of 1000 trials that will be distributed in 200 trials per session (twenty minutes per session). Participants assigned to ABM training condition will be trained implicitly to attend away from pain-related stimuli (i.e., facial expressions). They will be presented with a modified dot-probe task with trials including targets that often replaced neutral faces. Thus, 80% of trials (i.e., 160 trials) included targets that replaced neutral cue faces (pain incongruent trials: target appeared in the opposite side of pain-related faces). The rest of trials (i.e., 40 trials) belonged to pain congruent trials (i.e., target will occur in the same location of the pain-related facial expression).

By contrast, patients assigned to control condition were exposed to a standard visual dot-probe task in which targets were equally likely to replace pain or neutral cues (i.e., facial expressions) during pain trials (i.e., 50% pain-incongruent trials and 50% pain-congruent tri-als). The whole Control program will include a total of 1000 trials that will be distributed in 200 trials per session (twenty minutes per session).

Direct attention away from pain-related information (i.e., facial expressions) through implicit training procedures

Direct attention equally towards pain-related and neutral information (i.e., facial expressions) through implicit training procedures

Attentional bias will be assessed by dot-probe task. Behavioural reaction times outcomes will be recorder. The reaction time average for each dot-probe condition will be included as intrasubject factor and the training group as between-subject factor.

Attentional bias will be assessed by dot-probe task. Event-related potentials (ERPs) outcomes will be recorder. The P2 and N2 ERPs average amplitudes for each dot-probe condition will be included as intrasubject factor and the training group as between-subject factor.

Attentional bias will be assessed by dot-probe task. Behavioural reaction times outcomes will be recorder. To test the effect of the ABM procedure, the reaction time average for each dot-probe condition will be included as intrasubject factor and the training group as between-subject factor.

Behavioural attentional bias modification changes from baseline (pre-training vs 1 day post-training)

Attentional bias will be assessed by dot-probe task. ERPs outcomes will be recorder. To test the effect of the ABM procedure, ERPs amplitudes for each dot-probe condition will be included as intrasubject factor and the training group as between-subject factor.

Anxiety will be assessed by the Spanish version of the State-Trait Anxiety Inventory (STAI) questionnaire. The scale include 20 items and are scored using a four-point Likert scale, ranging from 0 to 3. Higher scores (i.e., > 60 percentile) represents high anxiety levels. Anxiety scores will be included as intrasubject factor and the training group as between-subject factor.

Depression will be assessed by the Spanish version of the Beck Depression Inventory (BDI). The scale include 21 items with four different statements describing various degrees of symptom intensity. Higher scores (i.e., > 21) represents greater severity of depressive symptoms. Depression scores will be included as intrasubject factor and the training group as between-subject factor.

Fear of pain will be assessed by the Spanish version of Fear of Pain Questionnaire (FPQ). In FPQ questionnaire participants are asked to rate in 30 items how fearful to pain experiences on a 5-point Likert scale. Higher scores represents greater severity of fear of pain symptoms. Fear of pain scores will be included as intrasubject factor and the training group as between-subject factor.

Pain worrying will be assessed by the Spanish versions of the Pain Catastrophizing Scale (PCS). In this scale, participants rated in 13 items the frequency of experiencing each catastrophic belief on a 0 to 4 Likert scale. Higher scores represents greater severity of pain worrying symptoms. Pain worrying scores will be included as intrasubject factor and the training group as between-subject factor.

Fibromyalgia impact will be assessed by the Spanish version of the Fibromyalgia Impact Questionnaire (FIQ). FIQ consists of 10 items for the assessment of three fibromyalgia domains (function, overall impact and symptoms). Higher scores represents greater severity of fibromyalgia impact symptoms. Fibromyalgia impact scores will be included as intrasubject factor and the training group as between-subject factor.

Pain status will be assessed by a visual analogue scale (VAS). The scale include 0 to 10 likert scale. Higher scores (i.e., > 6) represents greater severity of pain intensity symptoms. Pain scores will be included as intrasubject factor and the training group as between-subject factor.

Fatigue status will be assessed by a visual analogue scale (VAS). The scale include 0 to 10 likert scale. Higher scores (i.e., > 6) represents greater severity of fatigue intensity symptoms. Fatigue scores will be included as intrasubject factor and the training group as between-subject factor.

Inclusion Criteria: Fibromyalgia Diagnosis. Female sex The presence of clinical symptoms regarding anxiety or depression will be not exclusion criteria, as long as fibromyalgia was participants' primary diagnosis. Exclusion Criteria: Participation in the study will require the absence of neurological and psychiatric disorders that impair cognitive functions (i.e., stroke brain damage, psychosis, bipolar disorder, and substance abuse/dependence). Pregnancy Not being able to read Spanish in order to fill in the questionnaires

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