Abstract

Background & objectives: Attentional bias is a type of cognitive disorder, which involves a different part of human life. Substance abuse causes attention-related disorders by a reward system disturbing in the brain which causes attentional bias of substance-addicted patients toward substance-related visual cues (SRC). Methods: In this study, 15 Methamphetamine-addicted patients (MAP) participated as an experimental group and 15 normal people (without dependence on any stimulants) participated as a control group. A visual probe task was used to measure the attentional bias of participants toward Methamphetamine-related (MR) images and neutral images (NI). Ten pairs of MR images and NI were shown for all participants in ten trials. in every trial, after disappearing of each pair of images, a visual probe task was shown instead of the place of one of two images and participants were asked to press a button which depicts the place of the visual probe. The time duration for participants to press the correct button after appearing visual probe was considered as reaction time (RT) of participants. Results: Independent Samples T-test was used to determine the difference average RTs toward MR images between control and experimental group. The calculated P-value was 0.001 which was lesser than α (0.05). So the hypothesis which illustrates that average RTs of two groups are not equivalent was accepted in β (0.95) confidence level. Interpretation & conclusions: RT toward special visual stimuli can be considered as a criterion of attentional bias. The average RTs of experimental group participants toward MR images was lesser than average RTs of control group participants. It shows that the MAP is more sensitive to Methamphetamine-related visual stimuli so they have an attentional bias toward them.