Van Essen's deformation of monkey visual areas onto human cortical surface

(Van Essen & Drury, 1997, J Neurosci)

(Van Essen et al., 2001, Vis Res)

Posterior Parietal Cortex

(Culham, In press <Update>, Encyclopedia of Cognitive Science)

(Sakata et al., 1997, TINS)

(Lewis & Van Essen, 2000, J Comparative Neurology)

(Cavada, 2001, NeuroImage)

cIPS (Caudal Intraparietal Sulcus)

  • Lewis & Van Essen suggest it may be same as their LOP (lateral occipital parietal)

PIP (Posterior Intraparietal Sulcus)

  • Galletti (2001) suggests it's part of central representation of V6

LIP (Lateral Intraparietal Sulcus)

MIP (Medial Intraparietal Suclus)

VIP (Ventral Intraparietal Sulcus)

VIP Connectivity (Click images to enlarge)

(Lewis & Van Essen, 2000, J Comparative Neurology)

AIP (Anterior Intraparietal Sulcus)

AIP Connectivity

(Lewis & Van Essen, 2000, J Comparative Neurology)

This site <Broken link, not sure where it has been moved to> has a comprehensive review of the functions of various action-related parietal and frontal regions

Parieto-Occipital Cortex


  • Retinotopic
  • Visual only (no somatosensory)
  • No cortical magnification of central visual field (Galletti, 1999, Eur J Neurosci)

V6 Connectivity

(Galletti et al., 2001, Eur J Neurosci)

(Galletti et al., manuscript <Update>)


  • Non-retinotopic
  • Large central visual field representation
  • Larger RFs than V6
  • Connectivity indicates higher level than V6
  • Visual and somatosensory
  • Cells fire to somatosensory stimulation of contralateral arm
  • Cells fire to somatosensory stimulation in the dark (proprioception?, efference copy?)
  • Cells tuned to orientation, size, motion direction
  • Tuned to slow stimulus speeds
  • Complex visual responses (e.g., end-stopped, corners)
  • Attention-related activity
  • Tuned for direction of reach
  • "Real position cells": RFs do not change with eye position (but I don't think they varied head position so don't know if it's head- or body-centred)
  • Lesions led to deficits in reaching, wrist orientation and grasping (Battaglini et al, 2002, Exp Brain Res)
  • Inferior contralateral quadrant most represented (Galletti et al., 1999, Eur J Neurosci)

Somatosensory Cortex

(Iwamura, 1988, Current Opinion in Neurobiology)

SI (Primary Somatosensory Cortex)

  • 3a -- deep inputs (joints)
  • 3b -- cutaeneous input (skin)

SII (Secondary Somatosensory Cortex)

  • More affected by tactile attention than SI
  • Area 5
  • Area 7b

Frontal Premotor Cortex (Rizzolatti scheme)


  • Cells with visual/tactile RFs
  • Connected with VIP
  • Tactile and visual RFs around the face, body, arms and hands


  • Receives projections from AIP
  • Inactivation leads to grasping deficits