Five regions of the intraparietal sulcus (IPS): anterior, lateral, ventral, caudal, and medial •
LIP & VIP: involved in visual attention and
saccadic eye movements • VIP & MIP: visual control of reaching and pointing • AIP: visual control of grasping and manipulating hand movements • CIP: perception of depth from
stereopsis All of these areas have projections to the frontal lobe for executive control. Activity in the intraparietal sulcus has also been associated with the learning of sequences of finger movements. The
dorsal attention network includes the intraparietal sulcus of each hemisphere. The intraparietal sulcus is activated during voluntary orientation of attention.
Understanding numbers Behavioral studies suggest that the IPS is associated with impairments of basic
numerical magnitude processing and that there is a pattern of structural and functional alternations in the IPS and in the
PFC in
dyscalculia. Children with developmental dyscalculia were found to have less gray matter in the left IPS. Studies have shown that electrical activity in a particular group of nerve cells in the intraparietal sulcus spiked when, and only when, volunteers were performing calculations. Outside experimental settings it was also found that when a patient mentioned a number—or even a quantitative reference, such as "some more", "many" or "bigger than the other one"—there was a spike of electrical activity in the same nerve-cell population of the intraparietal sulcus that was activated when the patient was doing calculations under experimental conditions. Numerical magnitude processing refers to the cognitive ability to understand and compare numbers. This assists in tasks that involve estimation, mathematical processes, and decision-making. The intraparietal sulci are made up of two parts, left and right. The right intraparietal sulcus is involved more in non-symbolic numerical tasks, which involve estimation and spatial reasoning. The left intraparietal sulcus focuses on symbolic numerical tasks, which involves understanding symbols and mathematical operations. Studies have demonstrated that the right intraparietal sulcus shows more activity during magnitude estimation and length comparison tasks. Researchers discovered that disrupted activity in the right intraparietal lobe using
rTMS, (repetitive transcranial magnetic stimulation) resulted in participants having difficulties with performance in both the magnitude and length tasks. Studies have shown that children who show a larger change in brain activity in the left intraparietal sulcus tend to perform better at arithmetic tasks. This suggests that the left intraparietal sulcus plays an important role when it comes to numerical processing and mathematics. == Damage ==