Implicit Memory Function in Fibromyalgia Syndrome

Abstract

The study investigated implicit memory function in fibromyalgia syndrome (FMS) and its association with clinical parameters. Implicit memory refers to the influence of past experience on current behavior without conscious awareness of these experiences. Eighteen FMS patients and 25 healthy individuals accomplished a word-stem completion task. As possible factors mediating the expected impairment, pain severity, emotional disorders, and medication were taken into account. The patients displayed markedly reduced task performance and higher levels of depression and anxiety. Among the clinical features, pain severity was most closely associated with performance, whereas depression, anxiety, and medication showed only a minor impact. The study documented reduced implicit memory function in FMS. In contrast to former findings on impaired performance of FMS patients on classical memory tests, lower implicit memory function cannot be ascribed to motivational deficits. Instead, the aberrances may relate to functional inference between central nervous nociceptive activity and cognitive processing.

Keywords:

• chronic pain
• cognition
• fibromyalgia
• implicit memory

Notes

In order to determine possible dependence of the group difference in performance on the valence of the presented words, an ANOVA was conducted with the factors valence (positive, negative, neutral) and group (FMS vs control group). The interaction between both factors, which would indicate such a dependence, was not significant (F _2,82 = 0.029, p = .97, partial eta squared = .001).