Visual information processing in recently abstaining methamphetamine-dependent individuals: evoked potentials study

Abstract

We investigated changes in visually evoked potentials (VEPs) to pattern-reversal and motion-onset stimuli in a group of recently abstaining methamphetamine (MAP) abusers (5 females, 18 males, MAP abuse 5.32.8 years) and in 23 age- and gender-paired controls. We did not find differences between the groups in visual acuity.

In the group of MAP abusers we observed an attenuation of the early responses around 80 ms and a prolongation of the P1 peak latency after the reversal of high spatial frequency checkerboards (10 and 20 arc min checks). Furthermore, an attenuation of the latter positive response (170 to 250 ms) was observed among all the stimuli in parieto-frontal derivations for the MAP abusers.

Conclusions: This is the first report suggesting a slowing and attenuation of VEP responses during visual processing in abstaining methamphetamine abusers.