Multiple Neuronal Networks Mediate Sustained Attention

Abstract

Abstract& Sustained attention deficits occur in several neuropsychiatric disorders. However, the underlying neurobiological mechanisms are still incompletely understood. To that end, functional MRI was used to investigate the neural substrates of sustained attention (vigilance) using the rapid visual information processing (RVIP) task in 25 healthy volunteers. In order to better understand the neural networks underlying attentional abilities, brain regions where task-induced activation correlated with task performance were identified. Performance of the RVIP task activated a network of frontal, parietal, occipital, thalamic, and cerebellar regions. Deactivation during task performance was seen in the anterior and posterior cingulate, insula, and the left temporal and parahippocampal gyrus. Good task performance, as defined by better detection of target stimuli, was correlated with enhanced activation in predominantly right fronto-parietal regions and with decreased activation in predominantly left temporo-limbic and cingulate areas. Factor analysis revealed that these performance-correlated regions were grouped into two separate networks comprised of positively activated and negatively activated intercorrelated regions. Poor performers failed to significantly activate or deactivate these networks, whereas good performers either activated the positive or deactivated the negative network, or did both. The fact that both increased activation of task-specific areas and increased deactivation of task-irrelevant areas mediate cognitive functions underlying good RVIP task performance suggests two independent circuits, presumably reflecting different cognitive strategies, can be recruited to perform this vigilance task. &

Neuropsychological effects associated with recreational cocaine use

“…This particular sustained attention task is sensitive to dysfunction in the parietal and frontal lobe regions of the brain (e.g. Lawrence et al, 2003), areas also shown to be deficient in dopaminergic activity in chronic cocaine users (e.g. Volkow et al, 1993Volkow et al, , 1997Volkow et al, , 1999Martinez et al, 2007Martinez et al, , 2009).…”

fMRI reveals alteration of spatial working memory networks across adolescence

“…Medial frontal cortex is highly active at rest, during which it is involved in attentional monitoring of various internal and external stimuli (McKiernan et al, 2003). Medial frontal cortex under-activation during a cognitive task may represent reallocation of limited attentional resources to areas directly involved in task performance (Lawrence et al, 2003;McKiernan et al, 2003). Thus, SWM task demands may be more difficult for younger youths, who require greater attentional allocation to maintain performance, and therefore greater under-activation of medial frontal cortex.…”

Beyond common resources: the cortical basis for resolving task interference

“…Many previous studies have implicated these regions (particularly the DLPFC) in top-down control of processing, including the domains of selective attention (Mathalon et al, 2004;Milham et al, 2003), task-switching (Aron et al, 2004;Sussman et al, 2003), spatial attention (Giesbrecht et al, 2003;, sustained attention (Lawrence et al, 2003;Ortuno et al, 2002), emotional (Boshuisen et al, 2002;Milham et al, 2003), and autonomic control (Critchley et al, 2002(Critchley et al, , 2003. The finding that activation in this region (along with the right DLPFC) was significantly greater for No-go trials when compared to the Go trials is also consistent with the studies suggesting it monitors for response conflict Carter et al, 2001), whereby conflict signals the need for the allocation of additional control by the DLPFC (MacDonald et al, 2000).…”