Analysis of object motion in the ventral part of the medial superior temporal area of the macaque visual cortex

1993 ◽  
Vol 69 (1) ◽  
pp. 128-142 ◽  
Author(s):  
K. Tanaka ◽  
Y. Sugita ◽  
M. Moriya ◽  
H. Saito
Keyword(s):  
Visual Cortex ◽  
Receptive Fields ◽  
Object Motion ◽  
Ventral Part ◽  
Dorsal Part ◽  
Stationary Object ◽  
Temporal Area ◽  
Small Stimulus ◽  
Medial Superior Temporal ◽  
Stationary Background

1. The medial superior temporal area (MST) is an extrastriate area of the macaque visual cortex. Cells in MST have large receptive fields and respond to moving stimuli with directional selectivity. We previously suggested that the dorsal part of MST is mainly involved in analysis of field motion caused by movements of the animal itself, because most cells in the dorsal part preferentially responded to movements of a wide textured field rather than to movements of a small stimulus. To determine whether the remaining ventral part of MST differs in function from the dorsal part, we examined properties of cells in the ventral part in comparison with those of cells in the dorsal part, using anesthetized and paralyzed preparation. 2. Most cells in the ventral part preferably responded to movements of a small stimulus rather than to movements of a wide textured field. 3. Although the cells in the ventral part did not respond to movements of a textured field over a large window, many of them began to respond when a small stationary object was introduced in front of the moving field. The direction to which the cells responded in this stimulus configuration was opposite to the direction in which they responded to movements of an object on a stationary background. Activities of these cells thus represented the direction of relative movement of an object on a background, irrespective of whether the image of the object or the background moved on the retina. 4. We conclude that the ventral part of MST is distinctive from the dorsal part of MST and is mainly involved in the analysis of object movements in external space.

Underlying mechanisms of the response specificity of expansion/contraction and rotation cells in the dorsal part of the medial superior temporal area of the macaque monkey

1989 ◽  
Vol 62 (3) ◽  
pp. 642-656 ◽  
Author(s):  
K. Tanaka ◽  
Y. Fukada ◽  
H. A. Saito
Keyword(s):  
Receptive Fields ◽  
Spatial Arrangement ◽  
Macaque Monkey ◽  
The Other ◽  
Wide Field ◽  
Dorsal Part ◽  
Size Change ◽  
Temporal Area ◽  
Medial Superior Temporal ◽  
Underlying Mechanisms

1. The dorsal part of medial superior temporal area (MST) has two unique types of visually responsive cells: 1) expansion/contraction cells, which selectively respond to either an expansion or a contraction; and 2) rotation cells, which selectively respond to either a clockwise or a counterclockwise rotation. In addition to selectivity for the mode of motion, both types of cells respond preferentially to movements over a wide field rather than over a small field. With the aim of understanding the underlying mechanisms of these selectivities, we carried out experiments on immobilized monkeys anesthetized with N2O. 2. Expansion/contraction and rotation of a pattern extending over a wide field contain three stimulus factors: 1) the spatial arrangement of different directions of movement, 2) the gradient in the speed of regional movement from the center to the periphery of the stimulus, and 3) the size change of texture components of the pattern in the expansion/contraction and the acceleration of movement of texture components toward the center of the stimulus in the rotation. The contribution of each factor to the activation of the cells was evaluated by comparing the response before and after removing the factor from the stimulus. The moving stimuli that lacked one or two of the factors were produced by the use of a cinematographic animation technique. 3. Withdrawal of the first factor, the spatial arrangement of different directions of movement, reduced the response of both Expansion/contraction and Rotation cells much more severely than either of the other two factors. We concluded that the first factor is far more important for activation than the other two. 4. These results are consistent with the model that Expansion/contraction and Rotation cells receive converging inputs from many directional cells with relatively small receptive fields in different parts of the visual field. Because MST receives strong fiber projections from MT, MT cells are candidates for the input cells. According to the model, if the convergence is organized so that the preferred directions of the input cells are arranged radially, the target cell will be an Expansion/contraction cell; if the input cells are arranged circularly, a Rotation cell will result.

Response to Motion in Extrastriate Area MSTl: Disparity Sensitivity

1999 ◽  
Vol 82 (5) ◽  
pp. 2462-2475 ◽  
Author(s):  
Satoshi Eifuku ◽  
Robert H. Wurtz
Keyword(s):  
Receptive Field ◽  
Tuning Curve ◽  
Receptive Fields ◽  
Relative Difference ◽  
Moving Object ◽  
Absolute Difference ◽  
Stimulus Motion ◽  
Temporal Area ◽  
Moving Stimuli ◽  
Medial Superior Temporal

Many neurons in the lateral-ventral region of the medial superior temporal area (MSTl) have a clear center surround separation in their receptive fields. Either moving or stationary stimuli in the surround modulates the response to moving stimuli in the center, and this modulation could facilitate the perceptual segmentation of a moving object from its background. Another mechanism that could facilitate such segmentation would be sensitivity to binocular disparity in the center and surround regions of the receptive fields of these neurons. We therefore investigated the sensitivity of these MSTl neurons to disparity ranging from three degrees crossed disparity (near) to three degrees uncrossed disparity (far) applied to both the center and the surround regions. Many neurons showed clear disparity sensitivity to stimulus motion in the center of the receptive field. About [Formula: see text] of 104 neurons had a clear peak in their response, whereas another [Formula: see text] had broader tuning. Monocular stimulation abolished the tuning. The prevalence of cells broadly tuned to near and far disparity and the reversal of preferred directions at different disparities observed in MSTd were not found in MSTl. A stationary surround at zero disparity simply modulated up or down the response to moving stimuli at different disparities in the receptive field (RF) center but did not alter the disparity tuning curve. When the RF center motion was held at zero disparity and the disparity of the stationary surround was varied, some surround disparities produced greater modulation of MSTl neuron response than did others. Some neurons with different disparity preferences in center and surround responded best to the relative disparity differences between center and surround, whereas others were related to the absolute difference between center and surround. The combination of modulatory surrounds and the sensitivity to relative difference between center and surround disparity make these MSTl neurons particularly well suited for the segmentation of a moving object from the background.

Location and Functional Definition of Human Visual Motion Organization Using Functional Magnetic Resonance Imaging

2011 ◽  
pp. 18-27
Author(s):  
Tianyi Yan ◽  
Jinglong Wu
Keyword(s):  
Visual Field ◽  
Visual Motion ◽  
Receptive Fields ◽  
Superior Temporal Sulcus ◽  
Object Motion ◽  
Posterior Limb ◽  
Medial Superior Temporal ◽  
Processing Abilities ◽  
Mst Neurons ◽  
Definition Of

In humans, functional imaging studies have found a homolog of the macaque motion complex, MT+, which is suggested to contain both the middle temporal (MT) and medial superior temporal (MST) areas in the ascending limb of the inferior temporal sulcus. In the macaque, the motion-sensitive MT and MST areas are adjacent in the superior temporal sulcus. Electrophysiology has identified several motion-selective regions in the superior temporal sulcus (STS) of the macaque. Two of the best-studied areas include the MT and MST areas. The MT area has strong projections to the adjacent MST area and is typically subdivided into the dorsal (MSTd) and lateral (MSTl) subregions. While MT encodes the basic elements of motion, MST has higher-order motion-processing abilities and has been implicated in the perception of both object motion and self motion. The macaque MST area has been shown to have considerably larger receptive fields than the MT area. The receptive fields of MT cells typically extend only a few degrees into the ipsilateral visual field, while MST neurons have receptive fields that extend well into the ipsilateral visual field. This study tentatively identifies these subregions as the human homologs of the macaque MT and MST areas, respectively (Fig. 1). Putative human MT and MST areas were typically located on the posterior/ventral and anterior/dorsal banks of a dorsal/posterior limb of the inferior temporal sulcus. These locations are similar to their relative positions in the macaque superior temporal sulcus.

Size and shape of receptive fields in the medial superior temporal area (MST) of the macaque

Neuroreport ◽  
1997 ◽  
Vol 8 (12) ◽  
pp. 2803-2808 ◽  
Author(s):  
S Raiguel ◽  
M M. Van Hulle ◽  
D-K Xiao ◽  
V L. Marcar ◽  
L Lagae ◽  
...  
Keyword(s):  
Receptive Fields ◽  
Temporal Area ◽  
Size And Shape ◽  
Medial Superior Temporal

scholarly journals Processing of object motion and self-motion in the lateral subdivision of the medial superior temporal area in macaques

2019 ◽  
Vol 121 (4) ◽  
pp. 1207-1221 ◽  
Author(s):  
Ryo Sasaki ◽  
Dora E. Angelaki ◽  
Gregory C. DeAngelis
Keyword(s):  
Visual Cues ◽  
Moving Objects ◽  
Visual Motion ◽  
Object Motion ◽  
Image Motion ◽  
Motion Processing ◽  
Temporal Area ◽  
Medial Superior Temporal ◽  
Visual Motion Processing ◽  
Self Motion

Multiple areas of macaque cortex are involved in visual motion processing, but their relative functional roles remain unclear. The medial superior temporal (MST) area is typically divided into lateral (MSTl) and dorsal (MSTd) subdivisions that are thought to be involved in processing object motion and self-motion, respectively. Whereas MSTd has been studied extensively with regard to processing visual and nonvisual self-motion cues, little is known about self-motion signals in MSTl, especially nonvisual signals. Moreover, little is known about how self-motion and object motion signals interact in MSTl and how this differs from interactions in MSTd. We compared the visual and vestibular heading tuning of neurons in MSTl and MSTd using identical stimuli. Our findings reveal that both visual and vestibular heading signals are weaker in MSTl than in MSTd, suggesting that MSTl is less well suited to participate in self-motion perception than MSTd. We also tested neurons in both areas with a variety of combinations of object motion and self-motion. Our findings reveal that vestibular signals improve the separability of coding of heading and object direction in both areas, albeit more strongly in MSTd due to the greater strength of vestibular signals. Based on a marginalization technique, population decoding reveals that heading and object direction can be more effectively dissociated from MSTd responses than MSTl responses. Our findings help to clarify the respective contributions that MSTl and MSTd make to processing of object motion and self-motion, although our conclusions may be somewhat specific to the multipart moving objects that we employed. NEW & NOTEWORTHY Retinal image motion reflects contributions from both the observer’s self-motion and the movement of objects in the environment. The neural mechanisms by which the brain dissociates self-motion and object motion remain unclear. This study provides the first systematic examination of how the lateral subdivision of area MST (MSTl) contributes to dissociating object motion and self-motion. We also examine, for the first time, how MSTl neurons represent translational self-motion based on both vestibular and visual cues.

scholarly journals Spiral motion selective neurons in area MSTd contribute to judgments of heading

2014 ◽  
Vol 111 (11) ◽  
pp. 2332-2342 ◽  
Author(s):  
Hong Xu ◽  
Pascal Wallisch ◽  
David C. Bradley
Keyword(s):  
Optic Flow ◽  
Discrimination Task ◽  
Flow Patterns ◽  
Choice Probability ◽  
Dorsal Part ◽  
Significant Trial ◽  
Temporal Area ◽  
Spiral Motion ◽  
Medial Superior Temporal ◽  
Self Motion

Self-motion generates patterns of optic flow on the retina. Neurons in the dorsal part of the medial superior temporal area (MSTd) are selective for these optic flow patterns. It has been shown that neurons in this area that are selective for expanding optic flow fields are involved in heading judgments. We wondered how subpopulations of MSTd neurons, those tuned for expansion, rotation or spiral motion, contribute to heading perception. To investigate this question, we recorded from neurons in area MSTd with diverse tuning properties, while the animals performed a heading-discrimination task. We found a significant trial-to-trial correlation (choice probability) between the MSTd neurons and the animals' decision. Neurons in different subpopulations did not differ significantly in terms of their choice probability. Instead, choice probability was strongly related to the sensitivity of the neuron in our sample, regardless of tuning preference. We conclude that a variety of subpopulations of MSTd neurons with different tuning properties contribute to heading judgments.

scholarly journals Organization of Area hV5/MT+ in Subjects with Homonymous Visual Field Defects

2018 ◽  
Author(s):  
Amalia Papanikolaou ◽  
Georgios A. Keliris ◽  
T. Dorina Papageorgiou ◽  
Ulrich Schiefer ◽  
Nikos K. Logothetis ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Visual Field ◽  
Visual Perception ◽  
Activity Patterns ◽  
Receptive Fields ◽  
Visual Field Loss ◽  
Visual Sensitivity ◽  
Visual Field Defects ◽  
Temporal Area ◽  
Residual Capacity

AbstractDamage to the primary visual cortex (V1) leads to a visual field loss (scotoma) in the retinotopically corresponding part of the visual field. Nonetheless, a small amount of residual visual sensitivity persists within the blind field. This residual capacity has been linked to activity observed in the middle temporal area complex (V5/MT+). However, it remains unknown whether the organization of hV5/MT+ changes following V1 lesions. We studied the organization of area hV5/MT+ of five patients with dense homonymous defects in a quadrant of the visual field as a result of partial V1+ or optic radiation lesions. To do so, we developed a new method, which models the boundaries of population receptive fields directly from the BOLD signal of each voxel in the visual cortex. We found responses in hV5/MT+ arising inside the scotoma for all patients and identified two possible sources of activation: 1) responses might originate from partially lesioned parts of area V1 corresponding to the scotoma, and 2) responses can also originate independent of area V1 input suggesting the existence of functional V1-bypassing pathways. Apparently, visually driven activity observed in hV5/MT+ is not sufficient to mediate conscious vision. More surprisingly, visually driven activity in corresponding regions of V1 and early extrastriate areas including hV5/MT+ did not guarantee visual perception in the group of patients with post-geniculate lesions that we examined. This suggests that the fine coordination of visual activity patterns across visual areas may be an important determinant of whether visual perception persists following visual cortical lesions.

scholarly journals Primate Extrastriate Cortical Area MST: A Gateway between Sensation and Cognition

2021 ◽  
Author(s):  
Benedict Wild ◽  
Stefan Treue
Keyword(s):  
Visual Cortex ◽  
Temporal Cortex ◽  
Receptive Fields ◽  
Sensory Information ◽  
Action Planning ◽  
Motion Patterns ◽  
Medial Superior Temporal ◽  
Vestibular Cues ◽  
Primate Visual Cortex ◽  
Self Motion

Primate visual cortex consists of dozens of distinct brain areas, each providing a highly specialized component to the sophisticated task of encoding the incoming sensory information and creating a representation of our visual environment that underlies our perception and action. One such area is the medial superior temporal cortex (MST), a motion-sensitive, direction-selective part of the primate visual cortex. It receives most of its input from the middle temporal (MT) area, but MST cells have larger receptive fields and respond to more complex motion patterns. The finding that MST cells are tuned for optic flow patterns has led to the suggestion that the area plays an important role in the perception of self-motion. This hypothesis has received further support from studies showing that some MST cells also respond selectively to vestibular cues. Furthermore, the area is part of a network that controls the planning and execution of smooth pursuit eye movements and its activity is modulated by cognitive factors, such as attention and working memory. This review of more than 90 studies focuses on providing clarity of the heterogeneous findings on MST in the macaque cortex and its putative homolog in the human cortex. From this analysis of the unique anatomical and functional position in the hierarchy of areas and processing steps in primate visual cortex, MST emerges as a gateway between perception, cognition, and action planning. Given this pivotal role, this area represents an ideal model system for the transition from sensation to cognition.

scholarly journals Pursuit Speed Compensation in Cortical Area MSTd

2002 ◽  
Vol 88 (5) ◽  
pp. 2630-2647 ◽  
Author(s):  
Krishna V. Shenoy ◽  
James A. Crowell ◽  
Richard A. Andersen
Keyword(s):  
Eye Movements ◽  
Retinal Image ◽  
Visual Motion ◽  
Object Motion ◽  
Retinal Position ◽  
Temporal Area ◽  
Pursuit Eye Movements ◽  
Medial Superior Temporal ◽  
The Difference ◽  
Pursuit Velocity

When we move forward the visual images on our retinas expand. Humans rely on the focus, or center, of this expansion to estimate their direction of self-motion or heading and, as long as the eyes are still, the retinal focus corresponds to the heading. However, smooth pursuit eye movements add visual motion to the expanding retinal image and displace the focus of expansion. In spite of this, humans accurately judge their heading during pursuit eye movements even though the retinal focus no longer corresponds to the heading. Recent studies in macaque suggest that correction for pursuit may occur in the dorsal aspect of the medial superior temporal area (MSTd); neurons in this area are tuned to the retinal position of the focus and they modify their tuning to partially compensate for the focus shift caused by pursuit. However, the question remains whether these neurons shift focus tuning more at faster pursuit speeds, to compensate for the larger focus shifts created by faster pursuit. To investigate this question, we recorded from 40 MSTd neurons while monkeys made pursuit eye movements at a range of speeds across simulated self- or object motion displays. We found that most MSTd neurons modify their focus tuning more at faster pursuit speeds, consistent with the idea that they encode heading and other motion parameters regardless of pursuit speed. Across the population, the median rate of compensation increase with pursuit speed was 51% as great as required for perfect compensation. We recorded from the same neurons in a simulated pursuit condition, in which gaze was fixed but the entire display counter-rotated to produce the same retinal image as during real pursuit. This condition yielded the result that retinal cues contribute to pursuit compensation; the rate of compensation increase was 30% of that required for accurate encoding of heading. The difference between these two conditions was significant ( P < 0.05), indicating that extraretinal cues also contribute significantly. We found a systematic antialignment between preferred pursuit and preferred visual motion directions. Neurons may use this antialignment to combine retinal and extraretinal compensatory cues. These results indicate that many MSTd neurons compensate for pursuit velocity, pursuit direction as previously reported and pursuit speed, and further implicate MSTd as a critical stage in the computation of egomotion.

Analysis of motion of the visual field by direction, expansion/contraction, and rotation cells clustered in the dorsal part of the medial superior temporal area of the macaque monkey

1989 ◽  
Vol 62 (3) ◽  
pp. 626-641 ◽  
Author(s):  
K. Tanaka ◽  
H. Saito
Keyword(s):  
Visual Field ◽  
Macaque Monkey ◽  
Wide Field ◽  
Dorsal Part ◽  
Temporal Area ◽  
Rotation Direction ◽  
Medial Superior Temporal ◽  
Axis Rotation ◽  
Exact Size ◽  
Isotropic Expansion

1. The dorsal part of the medial superior temporal area (MST) is characterized by clusters of three types of visually responsive cells: Direction cells, which respond to a straight frontoparallel movement in a particular direction; Expansion/contraction cells, which selectively respond to either an expansion or contraction; and Rotation cells, which selectively respond to either a clockwise or counterclockwise rotation. To study their functional role, experiments were carried out on immobilized monkeys, anesthetized with N2O. 2. The areal extent of stimulation was crucial for activation: movements of a pattern extending over a wide visual field elicited a larger response than those elicited by a local pattern. 3. The shape, exact size, and sign of contrast of the texture components of the pattern were not important in determining the magnitude of response. 4. Different cells responded to different ranges of speed of movement. 5. Expansion/contraction cells were activated more strongly by a real (isotropic) expansion/contraction than by an "axial expansion/contraction" in which a pattern expanded or contracted along a particular axis. Rotation cells were activated more strongly by a circular rotation in the frontoparallel plane than by a shearing movement. 6. We discuss the possibility that the cells are involved in the detection and analysis of wide-field movements, which are generally caused by a movement of the animal itself. The mode (straight transfer, expansion/contraction, or rotation), direction, and speed of the relative movement of the animal and the external space may be represented by the activity of the cells.

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