scholarly journals Correction: Segregation of global and local motion processing in primate middle temporal visual area

Nature ◽  
1993 ◽  
Vol 365 (6443) ◽  
pp. 279-279
Author(s):  
Richard T. Born ◽  
Roger B. H. Tootell
Keyword(s):  
Visual Area ◽  
Motion Processing ◽  
Local Motion ◽  
Middle Temporal ◽  
Global And Local

Segregation of global and local motion processing in primate middle temporal visual area

Nature ◽  
1992 ◽  
Vol 357 (6378) ◽  
pp. 497-499 ◽  
Author(s):  
Richard T. Born ◽  
Roger B. H. Tootell
Keyword(s):  
Visual Area ◽  
Motion Processing ◽  
Local Motion ◽  
Middle Temporal ◽  
Global And Local

Center-Surround Interactions in the Middle Temporal Visual Area of the Owl Monkey

2000 ◽  
Vol 84 (5) ◽  
pp. 2658-2669 ◽  
Author(s):  
Richard T. Born
Keyword(s):  
Visual Motion ◽  
Receptive Fields ◽  
Visual Area ◽  
Motion Processing ◽  
Wide Field ◽  
Local Motion ◽  
Middle Temporal ◽  
Visual Motion Processing ◽  
Owl Monkey ◽  
Motion Contrast

Microelectrode recording and 2-deoxyglucose (2dg) labeling were used to investigate center-surround interactions in the middle temporal visual area (MT) of the owl monkey. These techniques revealed columnar groups of neurons whose receptive fields had opposite types of center-surround interaction with respect to moving visual stimuli. In one type of column, neurons responded well to objects such as a single bar or spot but poorly to large textured stimuli such as random dots. This was often due to the fact that the receptive fields had antagonistic surrounds: surround motion in the same direction as that preferred by the center suppressed responses, thus rendering these neurons unresponsive to wide-field motion. In the second set of complementary, interdigitated columns, neuronal receptive fields had reinforcing surrounds and responded optimally to wide-field motion. This functional organization could not be accounted for by systematic differences in binocular disparity. Within both column types, neurons whose receptive fields exhibited center-surround interactions were found less frequently in the input layers compared with the other layers. Additional tests were done on single units to examine the nature of the center-surround interactions. The direction tuning of the surround was broader than that of the center, and the preferred direction, with respect to that of the center, tended to be either in the same or opposite direction and only rarely in orthogonal directions. Surround motion at various velocities modulated the overall responsiveness to centrally placed moving stimuli, but it did not produce shifts in the peaks of the center's tuning curves for either direction or speed. In layers 3B and 5 of the local motion processing columns, a number of neurons responded only to local motion contrast but did so over a region of the visual field that was much larger than the optimal stimulus size. The central feature of this receptive field type was the generalization of surround antagonism over retinotopic space—a property similar to other “complex” receptive fields described previously. The columnar organization of different types of center-surround interactions may reflect the initial segregation of visual motion information into wide-field and local motion contrast systems that serve complementary functions in visual motion processing. Such segregation appears to occur at later stages of the macaque motion processing stream, in the medial superior temporal area (MST), and has also been described in invertebrate visual systems where it appears to be involved in the important function of distinguishing background motion from object motion.

scholarly journals Shared attentional resources for global and local motion processing

2007 ◽  
Vol 7 (10) ◽  
pp. 10 ◽  
Author(s):  
Paul F. Bulakowski ◽  
David W. Bressler ◽  
David Whitney
Keyword(s):  
Motion Processing ◽  
Local Motion ◽  
Attentional Resources ◽  
Global And Local

Visual motion processing in the anterior ectosylvian sulcus of the cat

1996 ◽  
Vol 76 (2) ◽  
pp. 895-907 ◽  
Author(s):  
J. W. Scannell ◽  
F. Sengpiel ◽  
M. J. Tovee ◽  
P. J. Benson ◽  
C. Blakemore ◽  
...  
Keyword(s):  
Visual Area ◽  
Motion Processing ◽  
Published Data ◽  
Anterior Ectosylvian Sulcus ◽  
Temporal Area ◽  
Middle Temporal ◽  
Visual Motion Processing ◽  
Pattern Motion ◽  
Middle Temporal Area ◽  
Component Motion

1. Neurons that are selectively sensitive to the direction of motion of elongated contours have been found in several cortical areas in many species. However, in the striate cortex of the cat and monkey, and the extrastriate posteromedial lateral suprasylvian visual area of the cat, such cells are generally component motion selective, signaling only the direction of movement orthogonal to the preferred orientation; a direction that is not necessarily the same as the motion of the entire pattern or texture of which the cell's preferred contour is part. The primate extrastriate middle temporal area is the only cortical region currently known to contain a substantial population of pattern-motion-selective cells that respond to the shared vector of motion of mixtures of contours. 2. From analyzing published data on the connectivity of the cat's cortex, we predicted that the anterior ectosylvian visual area (AEV), situated within the anterior ectosylvian sulcus, might be a higher-order motion processing area and thus likely to contain pattern-motion-selective neurons. This paper presents the results of a study on neuronal responses in AEV. 3. Ninety percent of AEV cells that responded strongly to drifting grating and/or plaid stimuli were directionally selective (directionality index > 0.5). For this group, the mean directionality index was 0.75. Moreover, 55% of these cells were unequivocally classified as pattern motion selective and only one neuron was classified as definitely component motion selective. Thus high-level pattern motion coding occurs in the cat extrastriate cortex and is not limited to the primate middle temporal area. 4. AEV contains a heterogeneous population of directionally selective cells. There was no clear relation between the degree of directional selectivity for plaids or gratings and the degree of selectivity for pattern motion or component motion. Nevertheless, 28% of the highly responsive cells were both more strongly modulated by plaids than gratings and more pattern motion selective than component motion selective. Such cells could correspond to a population of "selection units" signaling the salience of local motion information. 5. AEV lacks global retinotopic order but the preferred direction of motion of neurons (rather than axis of motion, as in the middle temporal area and the posteromedial lateral suprasylvian visual area) is mapped systematically across the cortex. Our data are compatible with AEV being a nonretinotopic, feature-mapped area in which cells representing similar parts of "motion space" are brought together on the cortical sheet.

Convergence of processing channels in the extrastriate cortex of monkeys

1990 ◽  
Vol 5 (6) ◽  
pp. 609-613 ◽  
Author(s):  
Leah Krubitzer ◽  
Jon Kaas
Keyword(s):  
Visual Tracking ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Visual Area ◽  
Extrastriate Cortex ◽  
Motion Processing ◽  
Middle Temporal ◽  
Visual Areas ◽  
Posterior Parietal ◽  
Visual Area Mt

AbstractThe first (V-I) and second (V-II) visual areas of primates contain three types of anatomical segregations of neurons as parts of hypothesized “P-B” or “color”, “P-I” or “form,” and “M” or “motion” processing channels. These channels remain distinct in relays of P-B and P-I information to the inferior temporal lobe via V-II and dorsolateral visual cortex for object recognition, and “M” information to posterior parietal cortex via the middle temporal visual area (MT) for visual tracking and attention. The present anatomical experiments demonstrate another channel where “P-B” modules in V-I and “P-B” and “M” modules in V-II merge in the projections to the dorsomedial visual area (DM), which relays to MT and posterior parietal cortex. This integrative area may function in unifying our perception of the visual world, and may allow “color” as well as “motion” to play a role in visual tracking and attention.

Improving motion detection via anodal transcranial direct current stimulation

2020 ◽  
Vol 38 (5) ◽  
pp. 395-405
Author(s):  
Luca Battaglini ◽  
Federica Mena ◽  
Clara Casco
Keyword(s):  
Direct Current ◽  
Signal To Noise Ratio ◽  
Individual Performance ◽  
Coherent Motion ◽  
Motion Processing ◽  
Global Motion ◽  
Local Motion ◽  
Processing Efficiency ◽  
Temporal Area ◽  
Direct Current Stimulation

Background: To study motion perception, a stimulus consisting of a field of small, moving dots is often used. Generally, some of the dots coherently move in the same direction (signal) while the rest move randomly (noise). A percept of global coherent motion (CM) results when many different local motion signals are combined. CM computation is a complex process that requires the integrity of the middle-temporal area (MT/V5) and there is evidence that increasing the number of dots presented in the stimulus makes such computation more efficient. Objective: In this study, we explored whether anodal direct current stimulation (tDCS) over MT/V5 would increase individual performance in a CM task at a low signal-to-noise ratio (SNR, i.e. low percentage of coherent dots) and with a target consisting of a large number of moving dots (high dot numerosity, e.g. >250 dots) with respect to low dot numerosity (<60 dots), indicating that tDCS favour the integration of local motion signal into a single global percept (global motion). Method: Participants were asked to perform a CM detection task (two-interval forced-choice, 2IFC) while they received anodal, cathodal, or sham stimulation on three different days. Results: Our findings showed no effect of cathodal tDCS with respect to the sham condition. Instead, anodal tDCS improves performance, but mostly when dot numerosity is high (>400 dots) to promote efficient global motion processing. Conclusions: The present study suggests that tDCS may be used under appropriate stimulus conditions (low SNR and high dot numerosity) to boost the global motion processing efficiency, and may be useful to empower clinical protocols to treat visual deficits.

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 Spatial heterogeneity of inhibitory surrounds in the middle temporal visual area.

1995 ◽  
Vol 92 (24) ◽  
pp. 11303-11306 ◽  
Author(s):  
D. K. Xiao ◽  
S. Raiguel ◽  
V. Marcar ◽  
J. Koenderink ◽  
G. A. Orban
Keyword(s):  
Spatial Heterogeneity ◽  
Visual Area ◽  
Middle Temporal
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