Publication Abstract Display
Type: Published Abstract
Title: Visuospatial attention and methamphetamine dependence: Increased regional fMRI activation and response latency.
Authors: Jacobson MW, Archibald SL, Grant I, Jernigan TL, and the HNRC Group
Year: 2005
Publication: Journal of the International Neuropsychological Society
Volume: 11 Issue: Suppl S1 Pages: 181
Abstract:To use a visual attention paradigm and functional neuroimaging to iden- tify methamphetamine-related changes in 1)fMRI activation patterns in striatal and parietal regions, and 2)response latency in spatial attention shifting. Participants were 7 methamphetamine dependent adults (METH+ group) and 6 matched controls. The visual attention-shifting paradigm uses numbers constructed from global/local Navon-type fig- ures. Using a response box, the subject identifies targets numbers (1 - 4) among distractors (5-9) appearing at either the global or local level in directed and divided attention conditions. FMRI results for whole- brain cluster analysis: the METH+ group had increased blood oxy- genation level dependent (BOLD)changes in response to the divided at- tention condition (p < .05), especially in thalamus, inferior and superior parietal and occipital lobes compared to controls. Behavioral data indi- cated that the METH+ group had significantly longer response latency in both directed and divided attention conditions (814 & 975 msec) compared to controls (623 msec & 746 msec respectively). Increased FMRI BOLD response in the METH+ group suggests a possible com- pensatory mechanism in neural regions supporting visuospatial atten- tion. Behavioral data indicate deficits in spatial attention-shifting, largely the result of increased latency when the switching response required in- hibition of prepotent global targets. These preliminary findings are con- sistent with recent studies noting brain structure/function alterations resulting from METH-related damage and neurotransmitter dysregu- lation. Behavioral data are consistent with inhibition, learning and at- tentional shifting deficits previously noted in this group.

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