Anatomical Substrates of the Alerting, Orienting and Executive Control Components of Attention: Focus on the Posterior Parietal Lobe

Abstract

Both neuropsychological and functional neuroimaging studies have identified that the posterior parietal lobe (PPL) is critical for the attention function. However, the unique role of distinct parietal cortical subregions and their underlying white matter (WM) remains in question. In this study, we collected both magnetic resonance imaging and diffusion tensor imaging (DTI) data in normal participants, and evaluated their attention performance using attention network test (ANT), which could isolate three different attention components: alerting, orienting and executive control. Cortical thickness, surface area and DTI parameters were extracted from predefined PPL subregions and correlated with behavioural performance. Tract-based spatial statistics (TBSS) was used for the voxel-wise statistical analysis. Results indicated structure-behaviour relationships on multiple levels. First, a link between the cortical thickness and WM integrity of the right inferior parietal regions and orienting performance was observed. Specifically, probabilistic tractography demonstrated that the integrity of WM connectivity between the bilateral inferior parietal lobules mediated the orienting performance. Second, the scores of executive control were significantly associated with the WM diffusion metrics of the right supramarginal gyrus. Finally, TBSS analysis revealed that alerting performance was significant correlated with the fractional anisotropy of local WM connecting the right thalamus and supplementary motor area. We conclude that distinct areas and features within PPL are associated with different components of attention. These findings could yield a more complete understanding of the nature of the PPL contribution to visuospatial attention.

Magnetoencephalography Slow-Wave Detection in Patients with Mild Traumatic Brain Injury and Ongoing Symptoms Correlated with Long-Term Neuropsychological Outcome

“…74,75 In a recent study, cognitive executive control and functioning was found to be associated with the white matter underlying the supramarginal gyrus, a region identified in the present study as exhibiting slow waves. 73 As our previous study in 2009 demonstrated that regions of white matter with reduction in intensity can link to the nearby slow-wave generating gray matter, there is a distinct possibility that slow waves generated in this area, and quite possibly other regions, that are correlating to poorer neurocognitive scores may be related to reduced anisotropy in the neighboring white matter region. 57 Although the study demonstrates relationships between affected regions of the brain and cognitive tests, it is important to note that we are not suggesting one-to-one correspondence between brain areas displaying slow waves and direct test measures.…”

“…[71][72][73] There is a growing consensus that attention and executive control are inter-related and share neural substrates. 74,75 In a recent study, cognitive executive control and functioning was found to be associated with the white matter underlying the supramarginal gyrus, a region identified in the present study as exhibiting slow waves.…”

Investigation of the segregated visual system

“…The dorsal attention network, responsible for goal-directed (top-down) attentional modulation, which includes parts of the dorsal parietal cortex (the superior parietal lobule and the intraparietal sulcus) and the superior frontal cortex (near or at the frontal eye field -FEF); whereas the ventral network driven by salient stimuli (bottom-up modulation), taking place in the temporoparietal junction and the inferior frontal cortex. The bottom-up orienting function proved to be negatively correlated with the cortical thickness in the angular gyrus and the superior parietal lobule and the mean diffusivity under the inferior parietal lobe (Yin et al, 2012). In contrast, the alteration of top-down attention functions was correlated with the FA in the superior frontal region (the white matter under the frontal-eye field, similarly as found in our analysis) (Yin et al, 2012).…”

“…The bottom-up orienting function proved to be negatively correlated with the cortical thickness in the angular gyrus and the superior parietal lobule and the mean diffusivity under the inferior parietal lobe (Yin et al, 2012). In contrast, the alteration of top-down attention functions was correlated with the FA in the superior frontal region (the white matter under the frontal-eye field, similarly as found in our analysis) (Yin et al, 2012). Interestingly, our analysis found both the dorsal and ventral attention systems to be active during this task.…”

Distinct parietal sites mediate the influences of mood, arousal, and their interaction on human recognition memory

“…One possibility is that emotional influences on recognition memory may be mediated by attention control mechanisms, of which the posterior parietal cortex is a key substrate (Ciavarro et al, 2013;Corbetta, Kincade, Ollinger, McAvoy, & Shulman, 2000;Han et al, 2004;Lane, Smith, Schenk, & Ellison, 2011;Yin et al, 2012). The posterior parietal cortex (PPC) is also one of the most commonly activated regions in fMRI studies of episodic memory and recognition (Kim, 2011;Wagner, Shannon, Kahn, & Buckner, 2005).…”