Sensitivity to expressions of pain in schizophrenia patients.

Patients with schizophrenia tend to neglect their own pain and are known to have impairments in the processing of facial expressions. However, the sensitivity to dynamic expressions of pain has not been studied in these patients. Our goal was to test this ability in schizophrenia and to probe the underlying cognitive processes. We hypothesized that patients would have a reduced sensitivity to expressions of pain and that this impairment would correlate with deficits in attention, working memory, basic emotions recognition and with positive symptoms. We applied a battery of tests composed of the Comprehensive Affect Testing System (CATS), Sensitivity to Expressions of Pain (STEP), Toulouse-Pierón, Stroop and Digit Span tests to two groups of individuals, 27 patients with the diagnosis of schizophrenia and 27 healthy volunteers, matched on age, education and gender. Symptoms were assessed using Brief Psychiatric Rating Scale. The sensitivity to expressions of pain was found to be impaired in schizophrenia and a bias to attribute lower pain intensities may be present at some discrimination levels. STEP performance was correlated with working memory but not with Affect Naming or attention. These findings may contribute to the improvement of cognitive remediation strategies.