The Duchess of Malfi

Last revised 2002

Fronto-striatal mechanisms of attentional control

Contains fulltext : 107952pub.pdf (publisher's version ) (Open Access)Radboud Universiteit Nijmegen, 8 november 2012Promotores : Cools, R., Buitelaar, J.K. Co-promotor : Ouden, H.E.M. de

The human basal ganglia modulate frontal-posterior connectivity during attention shifting

Contains fulltext : 87832.pdf (publisher's version ) (Open Access)Current models of flexible cognitive control emphasize the role of the prefrontal cortex. This region has been shown to control attention by biasing information processing in favor of task-relevant representations. However, the prefrontal cortex does not act in isolation. We used functional magnetic resonance imaging combined with nonlinear dynamic causal modeling to demonstrate that the basal ganglia play a role in modulating the top-down influence of the prefrontal cortex on visual processing in humans. Specifically, our results reveal that connectivity between the prefrontal cortex and stimulus-specific visual association areas depends on activity in the ventral striatopallidum, elicited by salient events leading to shifts in attention. These data integrate disparate literatures on top-down control by the prefrontal cortex and selective gating by the basal ganglia and highlight the importance of the basal ganglia for high-level cognitive control.9 p

Subcellular dynamics of somatostatin receptor subtype 1 in the rat arcuate nucleus: receptor localization and synaptic connectivity vary in parallel with the ultradian rhythm of growth hormone secretion

Contains fulltext : 81456.pdf (publisher's version ) (Open Access

Dopaminergic modulation of cognitive control: distinct roles for the prefrontal cortex and the basal ganglia.

Contains fulltext : 88805.pdf (publisher's version ) (Closed access)Evidence from psychopharmacological functional neuroimaging begins to elucidate the neurochemical mechanisms of cognitive control. The role of dopamine in two subcomponent processes of cognitive control is discussed: the active maintenance and the flexible updating of goal-relevant representations. A range of studies have highlighted a role for the prefrontal cortex (pFC) and its modulation by dopamine in the active maintenance of distractor-resistant goal-relevant representations. This work suggests that dopamine might modulate top-down signals from the pFC, thereby increasing the activity of posterior cortical regions that process goal-relevant representations and rendering them distractor-resistant. Conversely, other studies highlight a role for dopamine in the basal ganglia in cognitive switching, which might reflect a modulation of the selective gating of cortical cognitive and motor programs. We present a working hypothesis that integrates these two disparate literatures and states that the flexible adaptation of current goal-relevant representations is mediated by modulatory influences of activity in the dopamine-sensitive basal ganglia on connectivity between the prefrontal cortex and posterior cortex

Selective attentional enhancement and inhibition of fronto-posterior connectivity by the Basal Ganglia during attention switching

Contains fulltext : 153937.pdf (publisher's version ) (Closed access)The prefrontal cortex and the basal ganglia interact to selectively gate a desired action. Recent studies have shown that this selective gating mechanism of the basal ganglia extends to the domain of attention. Here, we investigate the nature of this action-like gating mechanism for attention using a spatial attention-switching paradigm in combination with functional neuroimaging and dynamic causal modeling. We show that the basal ganglia guide attention by focally releasing inhibition of task-relevant representations, while simultaneously inhibiting task-irrelevant representations by selectively modulating prefrontal top-down connections. These results strengthen and specify the role of the basal ganglia in attention. Moreover, our findings have implications for psychological theorizing by suggesting that inhibition of unattended sensory regions is not only a consequence of mutual suppression, but is an active process, subserved by the basal ganglia.8 p