Visual motion processing in substance addiction: an ERP study of heroin and methamphetamine groups

The present study employed event-related potential (ERP) technique combined with random dot kinetograms (RDK) tasks to investigate visual motion processing in methamphetamine group, heroin group, and healthy controls.

Two RDK conditions with 80% and 100% motion consistency were used to record transient ERP components (N1, N2, P2) and analyze group differences in visual motion processing.

① No significant group differences were found in N1 amplitude or latency (all p > 0.05); ② Heroin group showed significantly different N2 amplitudes from healthy controls at occipital O1/O2 electrodes (F (1, 49) = 4.534, p = 0.038, η²_p = 0.085), while no N2 differences were observed in methamphetamine group; after controlling for smoking frequency as a covariate, the main effect of group became non-significant (F (1, 45) = 2.660, p = 0.110, η²_p = 0.056); ③ Methamphetamine-dependent individuals exhibited significantly reduced P2 amplitude relative to healthy controls at fronto-central electrodes including Fz and FCz (F (1, 43) = 4.713, p = 0.036, η²_p = 0.099). A similar reduction in P2 amplitude was observed for heroin-dependent individuals at frontal and fronto-central electrodes including Fz, FCz, and FC4 (F (1, 45) = 5.988, p = 0.018, η²_p = 0.117). A Mixed-design repeated-measures ANOVAs further revealed a significant main effect of group on P2 latency at frontal sites (F7, F3, Fz, F4, F8, FC3, FCz) (F (2, 64) = 9.087, p < 0.001, η²_p = 0.221) and at central sites (C3, Cz) (F (2, 64) = 4.837, p = 0.011, η²_p = 0.131). Post hoc comparisons indicated that P2 latency was significantly shorter in the healthy control group than in the two addiction groups.

Chronic methamphetamine and heroin use impairs visual motion processing, with distinct neural mechanisms possibly mediating the effects of different addictive substances on fronto-parietal visual integration networks.

The research team used event-related potential (ERP) technology to explore the sensory and perceptual brain functions of individuals with substance addiction (including methamphetamine group and heroin addicts); based on the random dot kinematogram (RDK) experimental paradigm, the study revealed that the abuse of psychoactive substances impairs not only the frontal lobe but also the parietal cortex, thereby providing a new brain region-based basis for intervention in subsequent treatment.