• Cavada (2001) – The Visual Parietal Areas in the Macaque Monkey: Current Structural Knowledge and Ignorance
    • hand manipulation region (Sakata et al., 1995, 1998)
    • Colby & Goldberg (1999) – spatial representation dedicated to the visual guidance of grasping with the hand
    • receives projections about object shape from cIPS (Sakata et al., 1997; Sakata et al., 1999)
  • Culham & Kanwisher (2001) – Neuroimaging of cognitive functions in human parietal cortex
    • specialized for grasping (Taira et al., 1990)
    • neurons respond to visual and motor components of grasp and tuned to shapes to be grasped (Sakata & Taira, 1994)
  • Nakamura et al. (2001) – From Three-Dimensional Space Vision to Prehensile Hand Movements: The Lateral Intraparietal Area Links the Area V3A and the Anterior Intraparietal Area in Macaques
    • AIP projects to ventral premotor area 6 (Petrides & Pandya, 1984; Matelli et al., 1986; Johnson et al., 1996)
    • identified region in posterior LIP visually responsive to 3d stimuli in posterior LIP (corresponding to cIPS?)
      • used stereo visual stimuli with horizontal disparity
      • simple 3D objects (bar, cylinder, pyramid, cone, square plate, disk) – 20-60 degree in size, four orientations of 45 degree difference in 3 different planes
      • changed width, length, and thickness in double step size difference for objects with optimal response
      • recorded neural response to most effective object with and without disparity cues – neurons with greater response to disparity cues were classified as responsive to 3D objects
        • response activities increased linearly with increase in object size until some limit, then response decreased (surround inhibitory “off” field)
        • 56/76 were orientation selective
        • 17/43 preferred disk or square plate, 26/43 preferred bar or cylinder – spatially intermingled
    • used bidirectional WGA-HRP tracer – found V3A → LIP → AIP connection
      • tracer extended from layer 1 to layer 6 in LIP
      • heavy tracer in LIP, VIP, and V3a
      • slight tracer in MIP, PIP, PO, AIP
        • AIP – labels found mainly in layer 3, small amount in layer 4
    • used bidirectional tracers in V3A and retrograde tracers in AIP to show that the V3A → LIP connections terminate in the vicinity of the neurons in LIP that project to AIP
      • FB
        • AIP injection in lateral and posterior AIP and spread from layers 4 to 6 (layer 4 is main target of forward cortico-cortical projection neurons, Maunsell & Van Essen, 1983; Van Essen & Maunsell, 1983; Felleman & Van Essen, 1991)
        • LIP – tracer localized mainly in layer 3
      • NY
        • AIP injection in anterior AIP and spread from layers 3 to 6
        • LIP – tracer mainly in layer 3, most dense in anterior part, some in posterior
    • V3a projects throughout rostrocaudal extent of LIP, all of LIP projects to AIP


Connectivity of area AIP (from Lewis & Van Essen, 2000, J. Comparative Neurology)

Connectivity of area AIP (from Lewis & Van Essen, 2000, J. Comparative Neurology)



Response of one AIP neuron to grasps of different objects (from Murata et al. 2000)


Responses of several types of AIP neurons to grasps in different conditions (from Murata et al., 2000)