TY - JOUR
T1 - Functional organization of human posterior parietal cortex
T2 - Grasping- and reaching-related activations relative to topographically organized cortex
AU - Konen, Christina S.
AU - Mruczek, Ryan E.B.
AU - Montoya, Jessica L.
AU - Kastner, Sabine
PY - 2013/6/15
Y1 - 2013/6/15
N2 - The act of reaching to grasp an object requires the coordination between transporting the arm and shaping the hand. Neurophysiological, neuroimaging, neuroanatomic, and neuropsychological studies in macaque monkeys and humans suggest that the neural networks underlying grasping and reaching acts are at least partially separable within the posterior parietal cortex (PPC). To better understand how these neural networks have evolved in primates, we characterized the relationship between grasping- and reach-ing-related responses and topographically organized areas of the human intraparietal sulcus (IPS) using functional MRI. Grasping-specific activation was localized to the left anterior IPS, partially overlapping with the most anterior topographic regions and extending into the postcentral sulcus. Reaching-specific activation was localized to the left precuneus and superior parietal lobule, partially overlapping with the medial aspects of the more posterior topographic regions. Although the majority of activity within the topographic regions of the IPS was nonspecific with respect to movement type, we found evidence for a functional gradient of specificity for reaching and grasping movements spanning posterior-medial to anterior-lateral PPC. In contrast to the macaque monkey, grasp- and reach-specific activations were largely located outside of the human IPS.
AB - The act of reaching to grasp an object requires the coordination between transporting the arm and shaping the hand. Neurophysiological, neuroimaging, neuroanatomic, and neuropsychological studies in macaque monkeys and humans suggest that the neural networks underlying grasping and reaching acts are at least partially separable within the posterior parietal cortex (PPC). To better understand how these neural networks have evolved in primates, we characterized the relationship between grasping- and reach-ing-related responses and topographically organized areas of the human intraparietal sulcus (IPS) using functional MRI. Grasping-specific activation was localized to the left anterior IPS, partially overlapping with the most anterior topographic regions and extending into the postcentral sulcus. Reaching-specific activation was localized to the left precuneus and superior parietal lobule, partially overlapping with the medial aspects of the more posterior topographic regions. Although the majority of activity within the topographic regions of the IPS was nonspecific with respect to movement type, we found evidence for a functional gradient of specificity for reaching and grasping movements spanning posterior-medial to anterior-lateral PPC. In contrast to the macaque monkey, grasp- and reach-specific activations were largely located outside of the human IPS.
KW - Functional magnetic resonance imaging
KW - Intraparietal sulcus
KW - Prehension
KW - Superior parietal lobule
UR - http://www.scopus.com/inward/record.url?scp=84879174241&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84879174241&partnerID=8YFLogxK
U2 - 10.1152/jn.00657.2012
DO - 10.1152/jn.00657.2012
M3 - Article
C2 - 23515795
AN - SCOPUS:84879174241
SN - 0022-3077
VL - 109
SP - 2897
EP - 2908
JO - Journal of neurophysiology
JF - Journal of neurophysiology
IS - 12
ER -