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Functional Organization and Connections of the Middle Temporal Visual Area in the Macaque Monkey


Maunsell, John Henry Richard (1982) Functional Organization and Connections of the Middle Temporal Visual Area in the Macaque Monkey. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/zmmw-v278.


A variety of anatomical and physiological criteria have shown that the extrastriate visual cortex of the macaque monkey is subdivided into many distinct areas. There is evidence to suggest that there is functional specialization among these areas. Previous studies have shown that the middle temporal visual area (MT) contains a high proportion of cells which are selective for the direction of movement of visual stimuli, and yet relatively non-selective for stimulus color or form. The experiments reported here examined the response properties in MT in greater detail, and demonstrated the inputs and outputs of the area by means of anatomical tracers.

A computer-driven stimulator was used to examine quantitatively the responses of 163 single units from five anesthetized and paralyzed Macaca fascicularis. The experiments included tests of selectivity for stimulus direction, speed, orientation and disparity. Cells were also tested with stimuli which simulated trajectories with components of motion toward or away from the animal. The results show that in addition to direction selectivity, many cells in MT are sharply tuned for stimulus speed and disparity. This suggests that neurons in MT are well adapted for the analysis of motion in three-dimensional space.

Horseradish peroxidase and 3H-proline were injected into MT in three animals to demonstrate its anatomical inputs and outputs. Connections were seen with a large number of subcortical and cortical areas. In addition, connections with MT provide evidence contributing to the identification of two previously unrecognized cortical areas, which we have designated the medial superior temporal area (MST) and the ventral intraparietal area (VIP). The cortical layers in which projections originate and terminate are shown to provide objective anatomical criteria for assigning most cortical visual areas to a hierarchical order.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Biology
Degree Grantor:California Institute of Technology
Major Option:Biology
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Van Essen, David C.
Thesis Committee:
  • Allman, John Morgan (chair)
  • Hamilton, Charles R.
  • Hudspeth, James
  • Konishi, Masakazu
  • Van Essen, David C.
Defense Date:14 May 1982
Funding AgencyGrant Number
NIH5 T32 GM07737
NIH5 R01 EY02091
Jean Weigle Memorial FundUNSPECIFIED
Record Number:CaltechTHESIS:07122018-165408194
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:11120
Deposited By: Mel Ray
Deposited On:16 Jul 2018 23:26
Last Modified:03 Nov 2021 22:51

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