Working memory and attention in the young-adult and ageing human brain: distractor suppression and cortical-striatal loops. (360G-Wellcome-091826_Z_10_Z)

Working memory (WM) and selective attention (SA) are both vital in daily life, and may share common neural components, but the exact nature of their relation is unknown. Top-down control of distractor-filtering in WM, associated with a basal-ganglia/frontal/parietal mechanism, may contribute to an individual s WM capacity (McNab & Klingberg, 2008). Here we will address whether this mechanism is common to both WM and SA, and its generality or specificity across different types of distraction. The basal ganglia are highly innervated with dopamine receptors. Dopamine plays an important role in WM. With dopaminergic drugs we will interrogate the role of dopamine in distractor-filtering, for both WM and SA contexts. Recently we revealed some plasticity in the dopamine system of young adults with WM training (McNab et al., 2009). Here we will test whether specific training of distractor-filtering can offer greater benefit. This will also allow further tests of the association betwee n WM and SA. Following reports of age-related distractor-suppression deficits and striatal dopamine changes, I will test our hypothesis that the basal-ganglia/frontal mechanism is specifically affected by ageing, contributing to age-related WM and SA deficits. I shall also test whether distractor-filtering training and/or dopaminergic modulations can ameliorate such normal age-related deficits.