Visual Areas in Human Occipital Cortex

(Logothetis, N., November 1999. Vision: A window on consciousness. Scientific American)

Comparison of Monkey and Human Visual Areas

(Tootell, Tsao & Vanduffel. 2003. J. Neurosci. 23, 3981-3989)

V1 = primary visual cortex (along calcarine sulcus)
V2 / V3 / VP = extrastriate visual areas

  • Preliminary visual processing, properties become more complex and receptive fields become larger at higher levels
  • Each has a dorsal part (V1d, V2d and V3d, above calcarine representing lower visual field) and a ventral part (V1v, V2v, VP=V3v, below calcarine representing upper visual field)
  • Areas can be distinguished by mapping horizontal and vertical meridia of the visual field

Click images to enlarge

(Sereno et al., 1995)

(Engel et al., 1997)

V3A

  • junction of transverse occipital and intraparietal sulci
  • responds to visual motion
  • unlike lower-tier areas (V1d, V2d, V3d) which contain a quarter-field representation, V3A represents the entire contralateral hemifield

Click images to enlarge

(Tootell et al., 1997)

Transverse Occipital Sulcus (dotted line) & V3A (outline) (Tootell et al., 1997)

 

(Culham et al., 1998)

V3B

  • V3A (as defined by Tootell et al., 1997) may actually consist of 2 areas, V3A-proper and V3B (Smith et al, 1998)

(Smith et al., 1998)

V7

  • Anterior to V3A
  • Strong attentional responses
  • Possible homologue of macaque DP (a tentative area even in monkey)

(Tootell et al., 1998, The retinotopy of visual spatial attention. Neuron, 1409-1422)

V4v

  • Inferior temporal-occipital
  • Form perception?
  • Function not clear in humans yet
  • Boundaries and visual field maps of V4v and V8 are controversial in humans -- no consensus yet

V8

  • Anterior to V4
  • Color perception

MT+

  • Responds strongly to motion
  • "+" indicates that this is probably the same as monkey area MT (motion area) PLUS adjacent areas like MSTd, MSTl, FST

(Watson et al., 1995)

  • Sean Dukelow found one subregion that responds only to contralateral stimulation (likely MT-proper, orange) and one that also responds to ipsilateral stimulation (likely MST, yellow)

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(Dukelow et al., 2001)

KO (Kinetic Occipital) area

  • Orban and colleagues have proposed an area that responds to kinetic boundaries which lies posterior to MT+

KO (orange) vs. MT (red) and V3 (purple) KO (red arrow) vs. MT (green arrow)

(van Oostende et al., 1997)

V4d

  • Tootell and Hadjikhani (2001) propose an area V4d (dorsal V4) that seems to include the LO complex (LOC and LOP) and to overlap with what others called V3B and KO.
  • V4d does not respond to color but does respond to kinetic boundaries

(Tootell & Hadjikhani, 2001)