Cortical connections of the middle temporal visual area (MT) and the superior temporal cortex in owl monkeys

1984 ◽  
Vol 228 (1) ◽  
pp. 81-104 ◽  
Author(s):  
Rosalyn E. Weller ◽  
John T. Wall ◽  
Jon H. Kaas
Keyword(s):  
Temporal Cortex ◽  
Visual Area ◽  
Area Mt ◽  
Middle Temporal ◽  
Cortical Connections ◽  
Superior Temporal Cortex ◽  
Owl Monkeys ◽  
Visual Area Mt

Receptive-field properties of neurons in middle temporal visual area (MT) of owl monkeys

1984 ◽  
Vol 52 (3) ◽  
pp. 488-513 ◽  
Author(s):  
D. J. Felleman ◽  
J. H. Kaas
Keyword(s):  
Receptive Field ◽  
Stimulus Onset ◽  
Visual Area ◽  
Area Mt ◽  
Stimulus Movement ◽  
Middle Temporal ◽  
Preferred Direction ◽  
Direction Of Movement ◽  
Owl Monkeys ◽  
Visual Area Mt

Response properties of single neurons in the middle temporal visual area (MT) of anesthetized owl monkeys were determined and quantified for flashed and moving bars of light under computer control for position, orientation, direction of movement, and speed. Receptive-field sizes, ranging from 4 to 25 degrees in width, were considerably larger than receptive fields with corresponding eccentricities in the striate cortex. Neurons were highly binocular with most cells equally or nearly equally activated by either eye. Neurons varied in selectivity for axis and direction of moving bars. Some neurons demonstrated little or no selectivity, others were bidirectional on a single axis, while the largest group was highly selective for direction with little or no response to bar movement opposite to the preferred direction. Over 70% of neurons were classified as highly selective and 90% showed some preference for direction and/or axis of stimulus movement. Neurons typically responded to bar movement only over a restricted range of velocities. The majority of neurons responded best to a particular velocity within the 5-60 degrees/s range, with marked attenuation of the response for velocities greater or less than the preferred. Some neurons failed to show significant response attenuation even at the lowest tested velocity, while other neurons preferred velocities of 100 degrees/s or more and failed to attenuate to the highest velocities. Response magnitude varied with stimulus dimensions. Increasing the length of the moving bar typically increased the magnitude of the response slightly until the stimulus exceeded the receptive-field borders. Other neurons responded less to increases in bar length within the excitatory receptive field. Neurons preferred narrow bars less than 1 degree in width, and marked reductions in responses characteristically occurred with wider stimuli. Moving patterns of randomly placed small dots were often as effective as or more effective than single bars in activating neurons. Selectivity for direction of movement remained for the dot pattern. for the dot pattern. Poststimulus time (PST) histograms of responses to bars flashed at a series of 21 different positions across the receptive field, in the "response-plane" format, indicated a spatially and temporally homogeneous receptive-field structure for nearly all neurons. Cells characteristically showed transient excitation at both stimulus onset and offset for all effective stimulus locations. Some cells responded mainly at bright stimulus onset or offset.

scholarly journals The Organization of the Middle Temporal Visual Area (MT) in Bush Babies and Owl Monkeys Revealed by Optical Imaging

2004 ◽  
Vol 4 (8) ◽  
pp. 279-279
Author(s):  
I. Khaytin ◽  
X. Xu ◽  
C. E. Collins ◽  
P. M. Kaskan ◽  
D. W. Shima ◽  
...  
Keyword(s):  
Optical Imaging ◽  
Visual Area ◽  
Area Mt ◽  
Middle Temporal ◽  
Owl Monkeys ◽  
Visual Area Mt

Direction- and Velocity-Specific Responses from beyond the Classical Receptive Field in the Middle Temporal Visual Area (MT)

Perception ◽  
1985 ◽  
Vol 14 (2) ◽  
pp. 105-126 ◽  
Author(s):  
John Allman ◽  
Francis Miezin ◽  
EveLynn McGuinness
Keyword(s):  
Receptive Field ◽  
Visual Area ◽  
Area Mt ◽  
Motion Cues ◽  
Middle Temporal ◽  
Global Context ◽  
Mt Neurons ◽  
Classical Receptive Field ◽  
Local Stimulus ◽  
Visual Area Mt

The true receptive field of more than 90% of neurons in the middle temporal visual area (MT) extends well beyond the classical receptive field (crf), as mapped with conventional bar or spot stimuli, and includes a surrounding region that is 50 to 100 times the area of the crf. These extensive surrounds are demonstrated by simultaneously stimulating the crf and the surround with moving stimuli. The surrounds commonly have directional and velocity-selective influences that are antagonistic to the response from the crf. The crfs of MT neurons are organized in a topographic representation of the visual field. Thus MT neurons are embedded in an orderly visuotopic array, but are capable of integrating local stimulus conditions within a global context. The extensive surrounds of MT neurons may be involved in figure–ground discrimination, preattentive vision, perceptual constancies, and depth perception through motion cues.

The middle temporal visual area (MT) in the bushbaby,Galago senegalensis

1973 ◽  
Vol 57 (1) ◽  
pp. 197-202 ◽  
Author(s):  
J.M. Allman ◽  
J.H. Kaas ◽  
R.H. Lane
Keyword(s):  
Visual Area ◽  
Area Mt ◽  
Middle Temporal ◽  
Visual Area Mt ◽  
Galago Senegalensis

scholarly journals Cortical connections of visual area MT in the macaque

1986 ◽  
Vol 248 (2) ◽  
pp. 190-222 ◽  
Author(s):  
Leslie G. Ungerleider ◽  
Robert Desimone
Keyword(s):  
Visual Area ◽  
Area Mt ◽  
Cortical Connections ◽  
Visual Area Mt

Centrifugal directional bias in the middle temporal visual area (MT) of the macaque

1989 ◽  
Vol 2 (2) ◽  
pp. 177-188 ◽  
Author(s):  
Thomas D. Albright
Keyword(s):  
Visual Stimulation ◽  
Receptive Fields ◽  
Visual Area ◽  
Area Mt ◽  
Directional Bias ◽  
Middle Temporal ◽  
Naturally Occurring ◽  
Forward Locomotion ◽  
Visual Area Mt ◽  
Biased Distribution

AbstractWe have examined the distribution of preferred directions of motion for neurons in the middle temporal visual area (MT) of the macaque. We found a marked anisotropy favoring directions that are oriented away from the center of gaze. This anisotropy is present only among neurons with peripherally located receptive fields. This peripheral centrifugal directionality bias corresponds well to the biased distribution of motions characteristic of optic flow fields, which are generated by displacement of the visual world during forward locomotion. The bias may facilitate the processing of this common form of visual stimulation and could underlie previously observed perceptual anisotropies favoring centrifugal motion. We suggest that the bias could arise from exposure of modifiable cortical circuitry to a naturally occurring form of selective visual experience.

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