The classical Stroop interference task as a prefrontal activation probe: avalidation study using Tc-99(m)-ECD brain SPECT

This study investigated the feasibility of brain single photon emission com puted tomography (SPECT) functional imaging in a neuropsychological test se tting, following a single-day protocol with a split-dose paradigm. The Stro op Color Word Test (SCWT) is an example of a well-documented prefrontal act ivation task. In a split-dose protocol, ten right-handed health!: volunteer s were injected twice with 370 MBq Tc-99(m)-ethyl cysteinate dimer while pe rforming consecutively both series of card-reading of the SCWT. Images were reconstructed using filtered back-projection and normalized to a standard template in Talairach coordinates. Statistical Parametric Mapping (SPM96) w as used to determine voxelwise significant changes. A first activation clus ter was found in the left medial prefrontal cortex, consisting of the gyrus cinguli anterior and the gyrus frontalis medius and superior. A second act ivation cluster included the right gyrus frontalis dorsalis and medius. The se findings confirm to a large extent the results of previous functional ma gnetic resonance imaging, positron emission tomography studies of Stroop-li ke tasks. The choice and validity of various methodological characteristics of the experimental design leading to these results is critically discusse d. It is concluded that brain SPECT activation with the Stroop Color Word T est under standard neuropsychological conditions in healthy volunteers, is both technically and practically feasible. ( (C) 2001 Lippincott Williams & Wilkins).