Dorsal Stream Areas

Comparison of monkey and human parietal cortex

(Culham & Kanwisher, 2001)

cIPS (caudal intraparietal sulcus)

• shape and orientation processing in monkey
• not clear in humans yet
• in humans, the posterior IPS has strong attentional responses (Wojciulik & Kanwisher)

LIP (lateral intraparietal area)

• saccadic eye movements

LIP (posterior eye fields -- lower blobs)

(Muri et al., 1996. Location of human posterior eye field with functional magnetic resonance imaging, Journal of Neurology, Neurosurgery and Psychiatry, 60, 445-448)

Sereno's "saccadotopic" area (putatively LIP)

(Sereno, et al., 2001, Science )

Areas activated by visual field and hand (Medendorp et al., 2004, J Neurophys.)

VIP (ventral intraparietal area)

• multimodal motion responses (visual, auditory, tactile)
• motion towards face
• tactile responses for face

(Dukelow et al., submitted).

(Bremmer et al., 2001, Neuron)

AIP (anterior intraparietal area)

• grasping (encoding object shape for grasping)

(Binkofski et al, 1998, Neurology)

AIP-proper (rectangle) lies just posterior to somatosensory areas (circle)

(Culham, 2004, A&P book chapter)

Reach-related regions

Studies of reaching and pointing seem to find various combinations of two (or three) regions:

1 ) a region (POJ) at the superior end of the parieto-occipital sulcus

• activated by delayed pointing (Connolly et al., 2003; Astafiev et al., 2003)
• activated for reaching to peripheral targets (Prado et al., 2005)
• based on recent work from Pitzalis and colleagues (in press; VSS 2006), this may include the human equivalent of V6 (posterior to the POS) and V6A

2 ) a region (mIPS) medial to the intraparietal sulcus, in the anterior section of the superior parietal lobe

• activated by joystick movements (Grefkes et al., 2004)
• activated by reaching to foveal or peripheral targets (Prado et al., 2005)

fMRI activation during delayed pointing (Astafiev et al., 2003, J. Neurosci)

fMRI activation during delayed pointing (Connolly et al., 2003, Exp. Brain Res.)

Area which shows fMRI adaptation with repeated pointing movements to body parts (Pellijeff et al., in press, Neuropsychologia)

fMRI activation during reaching to foveated location (mIPS) or peripheral location (mIPS + POJ) (Prado et al., 2005, Neuron)

Wide-field retinotopy defines human cortical visual area V6 (Pitzalis et al., 2006, Journal of Neuroscience)

Brain activation related to the representations of external space and body scheme in visuomotor control (DeJong et al., 2001, NeuroImage)

Characterization of the human visual V6 complex by functional magnetic resonance imaging (Dechent & Frahm, 2003, European Journal of Neuroscience)

POS focus sensitive to luminance flicker [Various papers from R. Hari's lab]

fMRI activation during joystick movements to track a target (Grefkes et al., 2004, Neuroimage; figure from Grefkes & Fink, 2005, J. Anat.)

SPL (superior parietal lobule)

• parietal lobe above the intraparietal sulcus
• includes "area 5" (anterior) and "area 7" in humans (but confusingly, in monkeys, area 5 is in the SPL and area 7 is in the IPL -- there is much debate about how human and monkey parietal areas are related)
• strong attentional responses

IPL (inferior parietal lobule)

• parietal lobe below the intraparietal sulcus
• includes the supramarginal gyrus (area 40) and angular gyrus (area 39)