Functional Organization of Human Intraparietal and Frontal Cortex for Attending, Looking, and Pointing

Abstract

We studied the functional organization of human posterior parietal and frontal cortex using functional magnetic resonance imaging (fMRI) to map preparatory signals for attending, looking, and pointing to a peripheral visual location. The human frontal eye field and two separate regions in the intraparietal sulcus were similarly recruited in all conditions, suggesting an attentional role that generalizes across response effectors. However, the preparation of a pointing movement selectively activated a different group of regions, suggesting a stronger role in motor planning. These regions were lateralized to the left hemisphere, activated by preparation of movements of either hand, and included the inferior and superior parietal lobule, precuneus, and posterior superior temporal sulcus, plus the dorsal premotor and anterior cingulate cortex anteriorly. Surface-based registration of macaque cortical areas onto the map of fMRI responses suggests a relatively good spatial correspondence between human and macaque parietal areas. In contrast, large interspecies differences were noted in the topography of frontal areas.

Global familiarity of visual stimuli affects repetition-related neural plasticity but not repetition priming

“…Thus, superior parietal cortex has been shown to be involved in sensory-motor integration (Andersen, Snyder, Bradley, & Xing, 1997; Iacoboni, Woods, & Mazziotta, 1998;Tanabe, Kato, Miyauchi, Hayashi, & Yanagida, 2005) and motor attention (i.e., covert preparation of an upcoming movement, switching intended movements, hand-eye coordination) (Astafiev et al, 2003;Battaglia-Mayer & Caminiti, 2002;Rushworth, Johansen- Berg, Gobel, & Devlin, 2003). Consistent with this idea, large RS was also found in premotor cortex (BA 6), a region that is important for planning movements and that receives strong inputs from the superior parietal lobule (Schubotz & von Cramon, 2003;Wise, Boussaoud, Johnson, & Caminiti, 1997).…”

Effect of Cigarette Smoking on Prefrontal Cortical Function in Nondeprived Smokers Performing the Stroop Task

“…This difference between the two task conditions was not observed after smokers smoked a cigarette, nor was it exhibited by nonsmokers in either test. Literature regarding selective attention indicates that activity of the FEF (including the adjacent regions around the precentral sulcus) mediates shifts of attention and discrimination between targets and distracters (Astafiev et al, 2003;Hopfinger et al, 2000). For example, FEF neurons in monkeys are activated during discrimination between targets and distracters (Bichot and Schall, 1999;Thompson and Bichot, 2005); and the FEF is activated by distracters while human subjects perform an oddball task (Bledowski et al, 2004).…”

Parietal cortex and attention

“…There was condition-dependent modulation of the aIPS such that the grasping condition produced the most activation, followed in descending order by imagined grasping, visual discrimination, and color discrimination, which produced the least activation. The aIPS in humans might also be involved in preparatory activity for multieffector action [28]; the investigators observed activation in the aIPS when a lateralized visual target was covertly attended, fixated with a saccade, or pointed to with a finger ([29] see also Macaluso et al [25]). Interestingly, the aIPS was activated in tasks that involved a delay period between presentations of task-associated visual and/or tactile information, which suggests a role in sensorimotor transformation.…”

“…The question of whether or not the human aIPS is homologous to monkey AIP, which is involved in visually guided grasping, is still very much open [27,28,30]. In addition to the disagreement regarding the functional nature of aIPS, there is also variance in the peak Talairach coordinates listed for aIPS in each of these papers.…”

“…The aIPS in humans might also be involved in preparatory activity for multieffector action [28]; the investigators observed activation in the aIPS when a lateralized visual target was covertly attended, fixated with a saccade, or pointed to with a finger ([29] see also Macaluso et al [25]). Interestingly, the aIPS was activated in tasks that involved a delay period between presentations of task-associated visual and/or tactile information, which suggests a role in sensorimotor transformation.The question of whether or not the human aIPS is homologous to monkey AIP, which is involved in visually guided grasping, is still very much open [27,28,30]. In addition to the disagreement regarding the functional nature of aIPS, there is also variance in the peak Talairach coordinates listed for aIPS in each of these papers.…”