Measuring the stigma-sensitivity of psychotic patients in Hong Kong : the effect of stigma-related stimuli on emotional stroop task and attentional probe task

Abstract

Psychological distress aroused by stigma may lead to impairments in attentional functioning because it calls attention to the experience of stigma-related stress. Very few studies have actually considered whether stigma could disrupt attentional functioning by serving as distractors with emotional valence in the schizophrenia spectrum, given that there is a possible dysfunctional affective system in response to processing of emotional information.

This research employed the paradigm of emotional Stroop task and attentional probe task to investigate how stigma impacts on the functioning of selective attention. The primary objective of this current study was to investigate how selective attention, as measured in terms of reaction time and accuracy, can be disturbed by stigma-related stimuli in schizophrenia patients. The secondary objective of this study was to test the assumption that schizophrenic patients with higher sensitivity towards stigmatization will demonstrate higher impairment of selective attention in relation to stigma-related stimuli, since they may display more intense negative emotions than patients with lower sensitivity.

For emotional Stroop task, two categories of stimuli, including stigma-related words (emotional arousing to schizophrenic patients), furniture-related words (neutral stimuli) were shown in different colors and the subjects were instructed to name the color of words as fast and as accurate as possible. For attentional probe task, a stigma-related word was paired up with a furniture-related word in each trial. Participants had to respond as soon as they detect the dot in the position previously occupied by the words. Two groups of participants, healthy controls (N = 40) and patients with schizophrenia-related disorders (N = 40) were compared regarding their performances on emotional Stroop task and attentional probe task. The patients were further split into two groups; high-sensitivity towards stigma (N = 19) and low-sensitivity towards stigma(N = 18),for comparison on various variables, like level of symptoms, depression, medical adherence and awareness of mental disorders.

Based on the group comparison of performance on emotional Stoop task, schizophrenic patients exhibited significant emotional interference with the presentations of stigma-related words when compared with the healthy controls. Although the group comparison of performance on attentional probe task did not provide a significant result, schizophrenic subjects obtained higher difference scores which indicated that they were in general displayed more attentional bias towards stigma-related stimuli as compared to furniture-related stimuli. Both emotional Stroop and attentional probe task results show that schizophrenia patients in high-sensitivity subgroup demonstrated the greatest effect of emotional interference with the presentations of stigma-related words. Level of emotional interference for stigma-related stimuli in schizophrenic patients was moderately correlated with the measure of positive symptoms severity, and patients in high-sensitivity group had a significantly higher mean depressive symptoms score than patients in low-sensitivity group. Such information might help to identify potential risk factors and lead to improved treatment and prevention strategies for psychotic patients.