Emotional and Attentional Bias in Fibromyalgia: A Pilot ERP Study of the Dot-Probe Task

The present research investigates the neural correlates of attentional bias in fibromyalgia (FM) with a dot-probe task performed during an electroencephalogram (EEG) recording. For this purpose, 30 female participants were recruited, divided into two groups: a group of patients with FM (FM, n = 15, Mage = 51.87) and a healthy control group (HC) (HC, n = 15, Mage = 46.13). The results did not show behavioral differences between groups, but the EEG results showed that healthy controls had larger P300 amplitudes than patients with FM. Regarding late positive potentials (LPP), we found that patients with FM had larger amplitudes than healthy controls in a later time window. In summary, while the P300 results suggest that patients allocate less attentional resources to the task, the increased amplitudes of their LPP suggest augmented emotional processing of the target stimuli. Altogether, our results seem to support the thesis of generalized attentional deficits in FM. Fibromyalgia (FM) is a chronic musculoskeletal pain condition. There has been discussion in the scientific literature as to whether patients with FM suffer from a generalized attentional deficit or an attentional bias—preferentially selecting pain-related information. Attentional bias in FM patients has been studied as hypervigilance, which refers to early detection of pain-related information or innocuous information. Thus, the aim of this study was to test whether there is a generalized attentional deficit or attentional bias in relation to pain in patients with FM, by studying the neural activity underlying cognitive processes, specifically with evoked potentials (P300 and late positive potential—LPP). The P300 has been related to the use of attentional resources and the LPP to affective modulation. For this purpose, we studied two groups: a group of patients with FM and a healthy control group. Our hypotheses considered that FM patients, compared to healthy controls, would show an attentional bias for pain-related words (1) reflected in higher hits and shorter reaction time when detecting the target of a cognitive task (dot-probe), and (2) manifested by increased amplitudes of P300 and LPP evoked potentials while performing the task. The electrophysiological results suggest that FM patients may have a generalized attentional deficit and, despite this being the case, FM patients are more emotionally involved in the task.