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Journal articles on the topic 'Monkey visuomotor control'
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1
Zhang, Yan, Xue Wang, Steven L. Bressler, Yonghong Chen, and Mingzhou Ding. "Prestimulus Cortical Activity is Correlated with Speed of Visuomotor Processing." Journal of Cognitive Neuroscience 20, no. 10 (October 2008): 1915–25. http://dx.doi.org/10.1162/jocn.2008.20132.
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Response time (RT) is an important behavioral measure of the overall efficacy of sensorimotor processing and is known to vary significantly from trial to trial. Past work on how stimulus evoked cortical responses contribute to RT variability has helped delineate the stages of neuronal information processing. Much less is known about how the state of the brain immediately preceding the stimulus onset (prestimulus) affects RT. We addressed this problem by analyzing data from three macaque monkeys trained to perform a visuomotor pattern discrimination task. Local field potentials were recorded from up to 16 bipolar surface-to-depth electrodes widely distributed over one cerebral hemisphere in each monkey. The degree of linear correlation between RT and prestimulus spectral power was determined over a wide range of frequencies. In the prefrontal cortex, prestimulus power in the beta range (14–30 Hz) was negatively correlated with RT in two monkeys, suggesting a possible role of activity in this frequency range in the mediation of top-down control of visuomotor processing. In the sensorimotor cortex, prestimulus power in the beta range was positively correlated with RT in two monkeys, consistent with the hypothesis that oscillations in this range support the maintenance of steady-state motor output. In visual occipital and temporal lobe areas, prestimulus power in the alpha/low beta range (8–20 Hz) showed positive correlations with RT in three monkeys, possibly reflecting a spatially specific disengagement of visual anticipatory attention. Through measurement of prestimulus spectral coherence, it was further determined that sites showing similar patterns of correlation between spectral power and RT were also linked together in synchronized networks.
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Boussaoud, D. "Primate premotor cortex: modulation of preparatory neuronal activity by gaze angle." Journal of Neurophysiology 73, no. 2 (February 1, 1995): 886–90. http://dx.doi.org/10.1152/jn.1995.73.2.886.
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1. This study investigated whether the neuronal activity of a cortical area devoted to the control of limb movements is affected by variations in eye position within the orbit. Two rhesus monkeys were trained to perform a conditional visuomotor task with an instructed delay period while maintaining gaze on a fixation point. 2. The experimental design required each monkey to put its hand on a metal touch pad located at arm's length and fixate a small spot of light presented on a computer screen. Then a visual cue came on, at the fixation point or elsewhere, the color of which instructed the monkey to move its limb to one of two touch pads according to a conditional rule. A red cue meant a movement to the left, whereas a green one instructed a movement to the right. The cue lasted for a variable delay period (1-3 s), and the monkey had to wait for its offset, the go signal, before performing the correct response. The fixation point and the cues were presented at various screen locations in a combination that allowed examination of whether eye position and/or target position modulate the neuronal activity. Because the monkeys' heads were fixed, all changes in eye position reflected movements in a craniocentric, head-centered, coordinate space. 3. The activity of single neurons was recorded from dorsal premotor cortex (PMd). For most neurons (79%), the activity during the instructed delay period (set-related activity) reflects the direction of the upcoming limb movement but varies significantly with eye position.(ABSTRACT TRUNCATED AT 250 WORDS)
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Raos, Vassilis, Maria-Alessandra Umiltá, Vittorio Gallese, and Leonardo Fogassi. "Functional Properties of Grasping-Related Neurons in the Dorsal Premotor Area F2 of the Macaque Monkey." Journal of Neurophysiology 92, no. 4 (October 2004): 1990–2002. http://dx.doi.org/10.1152/jn.00154.2004.
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We investigated the properties of neurons located in the distal forelimb field of dorsal premotor area F2 of macaque monkey using a behavioral paradigm for studying the neuronal discharge during observation (object fixation condition) and grasping of different 3-dimensional objects with and without visual guidance of the movement (movement in light and movement in dark conditions, respectively). The main result is that almost all studied neurons were selective for both the type of prehension and the wrist orientation required for grasping an object. Three categories of neurons were found: purely motor, visually modulated, and visuomotor neurons. The discharge of purely motor neurons was not affected by either object presentation or by the visual feedback of the hand approaching to and interacting with the object. Visually modulated neurons presented a different discharge in the 2 movement conditions, this determining a decrease in selectivity for the grip and wrist orientation in the movement in dark condition. Visuomotor neurons typically discharged during the object fixation task even in the absence of any grasping movement. Nine of them also displayed a different discharge rate between the 2 movement conditions. Congruence was observed between the neuron response during the most effective type of prehension and the neuron response during observation of the object requiring that particular prehension. These results indicate an important role of F2 in the control of goal-related hand movements.
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Tankus, Ariel, and Itzhak Fried. "Visuomotor Coordination and Motor Representation by Human Temporal Lobe Neurons." Journal of Cognitive Neuroscience 24, no. 3 (March 2012): 600–610. http://dx.doi.org/10.1162/jocn_a_00160.
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The division of cortical visual processing into distinct dorsal and ventral streams is a key concept in primate neuroscience [Goodale, M. A., & Milner, A. D. Separate visual pathways for perception and action. Trends in Neurosciences, 15, 20–25, 1992; Steele, G., Weller, R., & Cusick, C. Cortical connections of the caudal subdivision of the dorsolateral area (V4) in monkeys. Journal of Comparative Neurology, 306, 495–520, 1991]. The ventral stream is usually characterized as a “What” pathway, whereas the dorsal stream is implied in mediating spatial perception (“Where”) and visually guided actions (“How”). A subpathway emerging from the dorsal stream and projecting to the medial-temporal lobe has been identified [Kravitz, D. J., Saleem, K. S., Baker, C. I., & Mishkin, M. A new neural framework for visuospatial processing. Nature Reviews Neuroscience, 12, 217–230, 2011; Cavada, C., & Goldman-Raiuc, P. S. Posterior parietal cortex in rhesus monkey: I. Parcellation of areas based on distinctive limbic and sensory cortico-cortical connections. Journal of Comparative Neurology, 287, 393–421, 1989]. The current article studies the coordination of visual information typically associated with the dorsal stream (“Where”), with planned movements, focusing on the temporal lobe. We recorded extracellular activity from 565 cells in the human medial-temporal and frontal lobes while 13 patients performed cued hand movements with visual feedback (visuomotor task), without feedback (motor task), or observed visual feedback without motor movement (visual-only task). We discovered two different neural populations in the human medial-temporal lobe. One consists of motor-like neurons representing hand position, speed or acceleration during the motor task but not during the visuomotor or visual tasks. The other is specific to the parahippocampal gyrus (an area known to process visual motion [Gur, M., & Snodderly, D. M. Direction selectivity in V1 of alert monkeys: Evidence for parallel pathways for motion processing. Journal of Physiology, 585, 383–400, 2007; Sato, N., & Nakamura, K. Visual response properties of neurons in the parahippocampal cortex of monkeys. Journal of Neurophysiology, 90, 876–886, 2003]) and encodes speed, acceleration, or direction of hand movements, but only during the visuomotor task: neither during visual-only nor during motor tasks. These findings suggest a functional basis for the anatomical subpathway between the dorsal stream and the medial-temporal lobe. Similar to the recent expansion of the motor control process into the sensory cortex [Matyas, F., Sreenivasan, V., Marbach, F., Wacongne, C., Barsy, B., Mateo, C., et al. Motor control by sensory cortex. Science, 330, 1240–1243, 2010], our findings render the human medial-temporal lobe an important junction in the process of planning and execution of motor acts whether internally or externally (visually) driven. Thus, the medial-temporal lobe might serve as an integration node between the two processing streams. Our findings thus shed new light on the brain mechanisms underlying visuomotor coordination which is a crucial capacity for everyday survival, whether it is identifying and picking up food, sliding a key into a lock, driving a vehicle, or escaping a predator.
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de Haan, Marcel Jan, Thomas Brochier, Sonja Grün, Alexa Riehle, and Frédéric V. Barthélemy. "Real-time visuomotor behavior and electrophysiology recording setup for use with humans and monkeys." Journal of Neurophysiology 120, no. 2 (August 1, 2018): 539–52. http://dx.doi.org/10.1152/jn.00262.2017.
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Large-scale network dynamics in multiple visuomotor areas is of great interest in the study of eye-hand coordination in both human and monkey. To explore this, it is essential to develop a setup that allows for precise tracking of eye and hand movements. It is desirable that it is able to generate mechanical or visual perturbations of hand trajectories so that eye-hand coordination can be studied in a variety of conditions. There are simple solutions that satisfy these requirements for hand movements performed in the horizontal plane while visual stimuli and hand feedback are presented in the vertical plane. However, this spatial dissociation requires cognitive rules for eye-hand coordination different from eye-hand movements performed in the same space, as is the case in most natural conditions. Here we present an innovative solution for the precise tracking of eye and hand movements in a single reference frame. Importantly, our solution allows behavioral explorations under normal and perturbed conditions in both humans and monkeys. It is based on the integration of two noninvasive commercially available systems to achieve online control and synchronous recording of eye (EyeLink) and hand (KINARM) positions during interactive visuomotor tasks. We also present an eye calibration method compatible with different eye trackers that compensates for nonlinearities caused by the system's geometry. Our setup monitors the two effectors in real time with high spatial and temporal resolution and simultaneously outputs behavioral and neuronal data to an external data acquisition system using a common data format. NEW & NOTEWORTHY We developed a new setup for studying eye-hand coordination in humans and monkeys that monitors the two effectors in real time in a common reference frame. Our eye calibration method allows us to track gaze positions relative to visual stimuli presented in the horizontal workspace of the hand movements. This method compensates for nonlinearities caused by the system’s geometry and transforms kinematics signals from the eye tracker into the same coordinate system as hand and targets.
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Scalaidhe, S. P., T. D. Albright, H. R. Rodman, and C. G. Gross. "Effects of superior temporal polysensory area lesions on eye movements in the macaque monkey." Journal of Neurophysiology 73, no. 1 (January 1, 1995): 1–19. http://dx.doi.org/10.1152/jn.1995.73.1.1.
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1. On the basis of its anatomic connections and single-unit properties, the superior temporal polysensory area (STP) would seem to be primarily involved in visuospatial functions. We have examined the effects of lesions of STP on saccadic eye movements, visual fixation, and smooth pursuit eye movements to directly test the hypothesis that STP is involved in visuospatial and visuomotor behavior. 2. Seven monkeys were trained to make saccades to targets 8, 15, and 22 degrees from a central fixation point along the horizontal meridian and 8 degrees from the central fixation point along the vertical meridian. One monkey was also trained to make saccades to auditory targets. The same monkeys were trained to foveate a stationary central fixation point and to follow it with a smooth pursuit eye movement when it began moving 5, 13, or 20 degrees/s. Four monkeys received unilateral STP lesions, one received a bilateral STP lesion, and as a control, two received unilateral inferior temporal cortex (IT) lesions. After testing, three of the animals with unilateral STP lesions received an additional STP lesion in the hemisphere contralateral to the first lesion. Similarly, one animal with a unilateral IT lesion received an additional IT lesion in the hemisphere contralateral to the first lesion. 3. All monkeys with complete removal of STP showed a significant increase in saccade latency to the most peripheral contralateral target, and most also had increased saccade latencies to the other contralateral targets. Saccades directed to targets along the vertical meridian or toward targets in the hemifield ipsilateral to the lesion were not impaired by removal of STP. By contrast, IT lesions did not impair the monkeys' ability to make saccadic eye movements to visual stimuli at any location, showing that saccades to visually guided targets are not impaired nonspecifically by damage to visual cortex. 4. The deficit in making eye movements after STP lesions was specific to saccade latency, with little effect on the accuracy of saccades to visual targets. 5. In the one monkey trained to make saccades to auditory targets, removal of STP did not impair saccades to auditory targets contralateral to its lesion, despite this monkey showing the largest increase in saccades latencies to visual targets. 6. There was complete recovery of saccade latency to the baseline level of performance on the saccade task after all STP lesions.(ABSTRACT TRUNCATED AT 400 WORDS)
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Brown, V. J., R. Desimone, and M. Mishkin. "Responses of cells in the tail of the caudate nucleus during visual discrimination learning." Journal of Neurophysiology 74, no. 3 (September 1, 1995): 1083–94. http://dx.doi.org/10.1152/jn.1995.74.3.1083.
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1. The tail of the caudate nucleus and adjacent ventral putamen (ventrocaudal neostriatum) are major projection sites of the extrastriate visual cortex. Visual information is then relayed, directly or indirectly, to a variety of structures with motor functions. To test for a role of the ventrocaudal neostriatum in stimulus-response association learning, or habit formation, neuronal responses were recorded while monkeys performed a visual discrimination task. Additional data were collected from cells in cortical area TF, which serve as a comparison and control for the caudate data. 2. Two monkeys were trained to perform an asymmetrically reinforced go-no go visual discrimination. The stimuli were complex colored patterns, randomly assigned to be either positive or negative. The monkey was rewarded with juice for releasing a bar when a positive stimulus was presented, whereas a negative stimulus signaled that no reward was available and that the monkey should withhold its response. Neuronal responses were recorded both while the monkey performed the task with previously learned stimuli and while it learned the task with new stimuli. In some cases, responses were recorded during reversal learning. 3. There was no evidence that cells in the ventrocaudal neostriatum were influenced by the reward contingencies of the task. Cells did not fire preferentially to the onset of either positive or negative stimuli; neither did cells fire in response to the reward itself or in association with the motor response of the monkey. Only visual responses were apparent. 4. The visual properties of cells in these structures resembled those of cells in some of the cortical areas projecting to them. Most cells responded selectively to different visual stimuli. The degree of stimulus selectivity was assessed with discriminant analysis and was found to be quantitatively similar to that of inferior temporal cells tested with similar stimuli. Likewise, like inferior temporal cells, many cells in the ventrocaudal neostriatum had large, bilateral receptive fields. Some cells had "doughnut"-shaped receptive fields, with stronger responses in the periphery of both visual fields than at the fovea, similar to the fields of some cells in the superior temporal polysensory area. Although the absence of task-specific responses argues that ventrocaudal neostriatal cells are not themselves the mediators of visual learning in the task employed, their cortical-like visual properties suggest that they might relay visual information important for visuomotor plasticity in other structures. (ABSTRACT TRUNCATED AT 400 WORDS)
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Costello, M. Gabriela, Dantong Zhu, Paul J. May, Emilio Salinas, and Terrence R. Stanford. "Task dependence of decision- and choice-related activity in monkey oculomotor thalamus." Journal of Neurophysiology 115, no. 1 (January 1, 2016): 581–601. http://dx.doi.org/10.1152/jn.00592.2015.
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Oculomotor signals circulate within putative recurrent feedback loops that include the frontal eye field (FEF) and the oculomotor thalamus (OcTh). To examine how OcTh contributes to visuomotor control, and perceptually informed saccadic choices in particular, neural correlates of perceptual judgment and motor selection in OcTh were evaluated and compared with those previously reported for FEF in the same subjects. Monkeys performed three tasks: a choice task in which perceptual decisions are urgent, a choice task in which identical decisions are made without time pressure, and a single-target, delayed saccade task. The OcTh yielded far fewer task-responsive neurons than the FEF, but across responsive pools, similar neuron types were found, ranging from purely visual to purely saccade related. Across such types, the impact of the perceptual information relevant to saccadic choices was qualitatively the same in FEF and OcTh. However, distinct from that in FEF, activity in OcTh was strongly task dependent, typically being most vigorous in the urgent task, less so in the easier choice task, and least in the single-target task. This was true for responsive and nonresponsive cells alike. Neurons with exclusively motor-related activity showed strong task dependence, fired less, and differed most patently from their FEF counterparts, whereas those that combined visual and motor activity fired most similarly to their FEF counterparts. The results suggest that OcTh activity is more distantly related to saccade production per se, because its degree of commitment to a motor choice varies markedly as a function of ongoing cognitive or behavioral demands.
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Suzuki, D. A., J. G. May, E. L. Keller, and R. D. Yee. "Visual motion response properties of neurons in dorsolateral pontine nucleus of alert monkey." Journal of Neurophysiology 63, no. 1 (January 1, 1990): 37–59. http://dx.doi.org/10.1152/jn.1990.63.1.37.
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1. In this study we sought to characterize the visual motion processing that exists in the dorsolateral pontine nucleus (DLPN) and make a comparison with the reported visual responses of the middle temporal (MT) and medial superior temporal (MST) areas of the monkey cerebral cortex. The DLPN is implicated as a component of the visuomotor interface involved with the regulation of smooth-pursuit eye movements, because it is a major terminus for afferents from MT and MST and also the source of efferents to cerebellar regions involved with eye-movement control. 2. Some DLPN cells were preferentially responsive to discrete (spot and bar) visual stimuli, or to large-field, random-dot pattern motion, or to both discrete and large-field visual motion. The results suggest differential input from localized regions of MT and MST. 3. The visual-motion responses of DLPN neurons were direction selective for 86% of the discrete visual responses and 95% of the large-field responses. Direction tuning bandwidths (full-width at 50% maximum response amplitude) averaged 107 degrees and 120 degrees for discrete and large-field visual motion responses, respectively. For the two visual response types, the direction index averaged 0.95 and 1.02, indicating that responses to stimuli moving in preferred directions were, on average, 20 and 50 times greater than responses to discrete or large-field stimulus movement in the opposite directions, respectively. 4. Most of the DLPN visual responses to movements of discrete visual stimuli exhibited increases in amplitude up to preferred retinal image speeds between 20 and 80 degrees/s, with an average preferred speed of 39 degrees/s. At higher speeds, the response amplitude of most units decreased, although a few units exhibited a broad saturation in response amplitude that was maintained up to at least 150 degrees/s before the response decreased. Over the range of speeds up to the preferred speeds, the sensitivity of DLPN neurons to discrete stimulus-related, retinal-image speed averaged 3.0 spikes/s per deg/s. The responses to large-field visual motion were less sensitive to retinal image speed and exhibited an average sensitivity of 1.4 spikes/s per deg/s before the visual response saturated. 5. DLPN and MT were quantitatively comparable with respect to degree of direction selectivity, retinal image speed tuning, and distribution of preferred speeds. Many DLPN receptive fields contained the fovea and were larger than those of MT and more like MST receptive fields in size.(ABSTRACT TRUNCATED AT 400 WORDS)
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Chen, L. L., and S. P. Wise. "Neuronal activity in the supplementary eye field during acquisition of conditional oculomotor associations." Journal of Neurophysiology 73, no. 3 (March 1, 1995): 1101–21. http://dx.doi.org/10.1152/jn.1995.73.3.1101.
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1. The supplementary eye field (SEF) has been viewed as a premotor cortical field for the selection and control of saccadic eye movements. Drawing on studies of the neighboring premotor cortex, we hypothesized that if the SEF participates in the selection of action based on arbitrary stimulus-response associations, then task-related activity in the SEF should change during the learning of such associations. 2. Rhesus monkeys were operantly conditioned to make a saccadic eye movement to one of four targets (7 deg up, down, left, and right from center) in response to a foveal instruction stimulus (IS). One and only one of those four possible responses was arbitrarily designated "correct" for each IS. The monkeys responded to familiar ISs, four stimuli that remained unchanged throughout training and recording, as well as to novel ISs, which the monkeys had not previously seen. The monkeys initially chose responses to novel stimuli by trial and error, with near chance levels of performance, but quickly learned to select the correct saccade. 3. We studied 186 SEF cells as monkeys learned new visuomotor associations. Neuronal activity was quantified in four task periods: during the presentation of the IS, during an instructed delay period (i.e., after the removal of the IS but before a trigger or "go" stimulus), just before the saccade, and after the saccade during fixation of the target location. The discharge rate in each task period was considered a separate case for analysis, compared with that in a reference period preceding the IS, and eliminated from further analysis if not significantly different. 4. We observed two main categories of activity change during learning, which we termed learning selective and learning dependent. Learning-selective cases showed a significant evolution in activity as the monkeys learned which saccade was instructed by a novel IS, but had no significant modulation during trials with familiar ISs. Many of these cells were virtually inactive on trials with familiar ISs. However, they initially showed dramatic modulation when tested with a novel IS. As the monkey chose the correct saccade (or target) with increasing reliability, the modulation often decremented until the cell was again relatively unmodulated, as observed during familiar-IS trials. These cells usually remained relatively inactive until the monkeys were challenged to start learning another new stimulus-response association. Learning-selective activity was observed in all task periods, and 33 (18%) of the 186 adequately tested SEF cells showed learning-selective activity in one or more task periods.(ABSTRACT TRUNCATED AT 400 WORDS)
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WEYAND, THEODORE G., and ADELE C. GAFKA. "Activity of neurons in area 6 of the cat during fixation and eye movements." Visual Neuroscience 15, no. 1 (January 1998): 123–40. http://dx.doi.org/10.1017/s0952523898151088.
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We studied the visuomotor properties of 645 neurons in area 6 of five cats trained in oculomotor tasks. The area we recorded from corresponds well with territories believed to contain the feline homologue of the frontal eye fields observed in primates. Despite an expectation that cells with pre-saccadic activity would be common, only a small fraction (∼5%) of the cells displayed activity that could be linked to subsequent saccadic eye movements. These pre-motor cells appeared to be distributed over a broad region of cortex mixed in with other cell types. As in primates, saccade-related activity tended to occur only during “purposeful” saccades. At least 30% (208/645) of the neurons were visual, with many of these cells possessing huge receptive fields that appeared to include the entire contralateral visual field. Visual responsiveness was generally attenuated by fixation during the oculomotor tasks. Although attentional mechanisms may play a role in this attenuation, this cortical area also exhibits powerful lateral interactions in which spatially displaced visual stimuli suppress each other. Most cells, visually responsive or not, were affected by fixation. Nearly equal proportions of cells showed increases or decreases in activity during fixation. For many of the cells affected by fixation, the source of this modulation appears to reflect cognitive, rather than sensory or motor processes. This included cells that showed anticipatory activity, and cells that responded to the reward only when it was presented in the context of the task. Based on the paucity of pre-saccadic neurons, it would be difficult to conclude that this region of cortex in the cat is homologous to the frontal eye fields of the monkey. However, when considered in the context of differences in the oculomotor habits of these two animals, we believe the homology fits. In addition to pre-motor neurons, the properties of several other cell types found in this area could contribute to the control of gaze.
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Brasted, Peter J., Timothy J. Bussey, Elisabeth A. Murray, and Steven P. Wise. "Fornix Transection Impairs Conditional Visuomotor Learning in Tasks Involving Nonspatially Differentiated Responses." Journal of Neurophysiology 87, no. 1 (January 1, 2002): 631–33. http://dx.doi.org/10.1152/jn.00656.2001.
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Rhesus monkeys learned a series of conditional visuomotor associations involving two-dimensional “objects” that instructed one of three responses: tapping a touch screen, steady contact with the screen for a brief period, or steady contact for a longer period. Relative to controls, fornix-transected monkeys were impaired in the acquisition of new associations and in the retention of preoperatively learned ones. These findings challenge the view that the hippocampal system participates in associative learning only when spatial information is relevant to either the stimulus or the response.
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White, Brian J., Robert A. Marino, Susan E. Boehnke, Laurent Itti, Jan Theeuwes, and Douglas P. Munoz. "Competitive Integration of Visual and Goal-related Signals on Neuronal Accumulation Rate: A Correlate of Oculomotor Capture in the Superior Colliculus." Journal of Cognitive Neuroscience 25, no. 10 (October 2013): 1754–65. http://dx.doi.org/10.1162/jocn_a_00429.
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The mechanisms that underlie the integration of visual and goal-related signals for the production of saccades remain poorly understood. Here, we examined how spatial proximity of competing stimuli shapes goal-directed responses in the superior colliculus (SC), a midbrain structure closely associated with the control of visual attention and eye movements. Monkeys were trained to perform an oculomotor-capture task [Theeuwes, J., Kramer, A. F., Hahn, S., Irwin, D. E., & Zelinsky, G. J. Influence of attentional capture on oculomotor control. Journal of Experimental Psychology. Human Perception and Performance, 25, 1595–1608, 1999], in which a target singleton was revealed via an isoluminant color change in all but one item. On a portion of the trials, an additional salient item abruptly appeared near or far from the target. We quantified how spatial proximity between the abrupt-onset and the target shaped the goal-directed response. We found that the appearance of an abrupt-onset near the target induced a transient decrease in goal-directed discharge of SC visuomotor neurons. Although this was indicative of spatial competition, it was immediately followed by a rebound in presaccadic activation, which facilitated the saccadic response (i.e., it induced shorter saccadic RT). A similar suppression also occurred at most nontarget locations even in the absence of the abrupt-onset. This is indicative of a mechanism that enabled monkeys to quickly discount stimuli that shared the common nontarget feature. These results reveal a pattern of excitation/inhibition across the SC visuomotor map that acted to facilitate optimal behavior—the short duration suppression minimized the probability of capture by salient distractors, whereas a subsequent boost in accumulation rate ensured a fast goal-directed response. Such nonlinear dynamics should be incorporated into future biologically plausible models of saccade behavior.
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Marino, Robert A., Ron Levy, and Douglas P. Munoz. "Linking express saccade occurance to stimulus properties and sensorimotor integration in the superior colliculus." Journal of Neurophysiology 114, no. 2 (August 2015): 879–92. http://dx.doi.org/10.1152/jn.00047.2015.
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Express saccades represent the fastest possible eye movements to visual targets with reaction times that approach minimum sensory-motor conduction delays. Previous work in monkeys has identified two specific neural signals in the superior colliculus (SC: a midbrain sensorimotor integration structure involved in gaze control) that are required to execute express saccades: 1) previsual activity consisting of a low-frequency increase in action potentials in sensory-motor neurons immediately before the arrival of a visual response; and 2) a transient visual-sensory response consisting of a high-frequency burst of action potentials in visually responsive neurons resulting from the appearance of a visual target stimulus. To better understand how these two neural signals interact to produce express saccades, we manipulated the arrival time and magnitude of visual responses in the SC by altering target luminance and we examined the corresponding influences on SC activity and express saccade generation. We recorded from saccade neurons with visual-, motor-, and previsual-related activity in the SC of monkeys performing the gap saccade task while target luminance was systematically varied between 0.001 and 42.5 cd/m2 against a black background (∼0.0001 cd/m2). Our results demonstrated that 1) express saccade latencies were linked directly to the arrival time in the SC of visual responses produced by abruptly appearing visual stimuli; 2) express saccades were generated toward both dim and bright targets whenever sufficient previsual activity was present; and 3) target luminance altered the likelihood of producing an express saccade. When an express saccade was generated, visuomotor neurons increased their activity immediately before the arrival of the visual response in the SC and saccade initiation. Furthermore, the visual and motor responses of visuomotor neurons merged into a single burst of action potentials, while the visual response of visual-only neurons was unaffected. A linear combination model was used to test which SC signals best predicted the likelihood of producing an express saccade. In addition to visual response magnitude and previsual activity of saccade neurons, the model identified presaccadic activity (activity occurring during the 30-ms epoch immediately before saccade initiation) as a third important signal for predicting express saccades. We conclude that express saccades can be predicted by visual, previsual, and presaccadic signals recorded from visuomotor neurons in the intermediate layers of the SC.
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Tian, J. R., and J. C. Lynch. "Corticocortical input to the smooth and saccadic eye movement subregions of the frontal eye field in Cebus monkeys." Journal of Neurophysiology 76, no. 4 (October 1, 1996): 2754–71. http://dx.doi.org/10.1152/jn.1996.76.4.2754.
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1. The locations and connections of the smooth and saccadic eye movement subregions of the frontal eye field (FEFsem and FEFsac, respectively) were investigated in seven hemispheres of five Cebus monkeys. The supplementary eye field was also mapped in seven hemispheres and the hand/arm regions of the dorsal and ventral premotor areas were localized in five hemispheres. Monkeys were immobilized during experiments with Telazol, a dissociative anesthetic agent that has no significant effect on microstimulation-induced eye movement parameters (threshold, velocity, and duration). The functional subregions were defined with the use of low threshold intracortical microstimulation (current < or = 50 microA). Then different retrogradely transported fluorescent tracers were placed into these functionally defined regions. 2. The FEFsac in Cebus monkey is in the same location as the one in macaque monkeys, which is in Walker's areas 8a and 45. The FEFsem is located in the posterior shoulder of the superior arcuate sulcus near its medial tip and is therefore more accessible for tracer injections than the one in macaque monkeys. This subregion is within cytoarchitectural area 6a beta, which is distinct from the adjacent area 6a alpha (dorsal premotor area). This smooth eye movement subregion may be comparable with the one in macaque monkeys. 3. Cortical connection patterns of the FEFsac and FEFsem are similar and parallel to each other. The predominant neural input to these two subregions originates in other cortical eye fields, including the supplementary eye field, the parietal eye field, the middle superior temporal area, and the principal sulcus region. These cortical eye fields each contain two separate, almost non-overlapping, distributions of labeled neurons that project to the corresponding frontal eye field (FEF) subregions. These results suggest that there may be similar, but relatively independent, parallel corticocortical networks to control pursuit and saccadic eye movements. The weak connections between the middle temporal area (MT) and FEF suggest that the MT may not provide the major source of visuomotion inputs to the FEF, but that it rather plays a role in mediating visual information that is relayed from the striate and extrastriate cortices via MT to the parietal cortex and then to the FEF. In addition to the well-known neural connections between the lateral intraparietal area and the FEF, additional parietal projections have been demonstrated from the dorsomedial visual area area specifically to the FEFsac and from area 7m specifically to the FEFsem.
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Ferraina, Stefano, Alexandra Battaglia-Mayer, Aldo Genovesio, Barbara Marconi, Paolo Onorati, and Roberto Caminiti. "Early Coding of Visuomanual Coordination During Reaching in Parietal Area PEc." Journal of Neurophysiology 85, no. 1 (January 1, 2001): 462–67. http://dx.doi.org/10.1152/jn.2001.85.1.462.
Full textAbstract:
The parietal mechanisms of eye-hand coordination during reaching were studied by recording neural activity in area PEc while monkeys performed different tasks, aimed at assessing the influence of retinal, hand-, and eye-related signals on neural activity. The tasks used consisted of 1) reaching to foveated and 2) to extra-foveal targets, with constant eye position; and 3) saccadic eye movement toward, and holding of eye position on peripheral targets, the same as those of the reaching tasks. In all tasks, hand and/or eye movements were made from a central position to eight peripheral targets. A conventional visual fixation paradigm was used as a control task, to assess location and extent of visual receptive field of neurons. A large proportion of cells in area PEc displayed significant relationships to hand movement direction and position. Many of them were also related to the eye's position. Relationships to saccadic eye movements were found for a smaller proportion of cells. Most neurons were tuned to different combination of hand- and eye-related signals; some of them were also influenced by visual information. This combination of signals can be an expression of the early stages of the composition of motor commands for different forms of visuomotor coordination that depend on the integration of hand- and eye-related information. These results assign to area PEc, classically considered as a somatosensory association cortex, a new visuomotor role.
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Gattass, Ricardo, Sheila Nascimento-Silva, Juliana G. M. Soares, Bruss Lima, Ana Karla Jansen, Antonia Cinira M. Diogo, Mariana F. Farias, et al. "Cortical visual areas in monkeys: location, topography, connections, columns, plasticity and cortical dynamics." Philosophical Transactions of the Royal Society B: Biological Sciences 360, no. 1456 (April 29, 2005): 709–31. http://dx.doi.org/10.1098/rstb.2005.1629.
Full textAbstract:
The visual system is constantly challenged to organize the retinal pattern of stimulation into coherent percepts. This task is achieved by the cortical visual system, which is composed by topographically organized analytic areas and by synthetic areas of the temporal lobe that have more holistic processing. Additional visual areas of the parietal lobe are related to motion perception and visuomotor control. V1 and V2 represent the entire visual field. MT represents only the binocular field, and V4 only the central 30°–40°. The parietal areas represent more of the periphery. For any eccentricity, the receptive field grows at each step of processing, more at anterior areas in the temporal lobe. Minimal point image size increases towards the temporal lobe, but remains fairly constant toward the parietal lobe. Patterns of projection show asymmetries. Central V2 and V4 project mainly to the temporal lobe, while peripherals V2 (more than 30°) and V4 (more than 10°) also project to the parietal lobe. Visual information that arrives at V1 projects to V2, MT and PO, which then project to other areas. Local lateral propagation and recursive loops corroborate to perceptual completion and filling in. Priority connections to temporal, parietal and parieto-temporal cortices help construct crude early representations of objects, trajectories and movements.
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Lee, Daeyeol, and Stephan Quessy. "Activity in the Supplementary Motor Area Related to Learning and Performance During a Sequential Visuomotor Task." Journal of Neurophysiology 89, no. 2 (February 1, 2003): 1039–56. http://dx.doi.org/10.1152/jn.00638.2002.
Full textAbstract:
Monkeys were trained in a serial reaction time task to produce hand movements according to changing locations of visual targets. In most trials, targets followed the same sequence repeatedly, whereas in other trials targets were presented in random locations or switched unpredictably between two alternative sequences. Single-unit activity was recorded from the caudal supplementary motor area (SMA-proper). Based on the activity associated with random movement sequences, effects of hand position and movement direction were evaluated. Activity was influenced by the hand position in ∼60% of the neurons, and the movement direction influenced the activity of 51% of the neurons. In addition, 37 and 71% of SMA neurons displayed nonstationarity in their activity across successive movements within a given trial and across trials, respectively. Such nonstationarity in the ongoing neural activity and the effects of performance-related variables were evaluated using a regression model and separated from learning-related activity changes. About a third of SMA neurons displayed gradual changes in neural activity related to experience with a movement sequence across trials. Furthermore, about a quarter of SMA neurons showed similar changes within individual trials. When the individual movements included in the frequently repeated movement sequences were introduced unexpectedly, learning-related changes in neural activity were reduced, indicating that many SMA neurons changed their activity in relation to the learning of particular movement sequences. These results suggest that the pattern of neural activity in the cortical network involved in the control of movement sequences can be modified continuously by experience.
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Blaizot, Xavier, Brigitte Landeau, Jean-Claude Baron, and Chantal Chavoix. "Mapping the Visual Recognition Memory Network with PET in the Behaving Baboon." Journal of Cerebral Blood Flow & Metabolism 20, no. 2 (February 2000): 213–19. http://dx.doi.org/10.1097/00004647-200002000-00001.
Full textAbstract:
By means of a novel 18F-fluoro-deoxyglucose PET method designed for cognitive activation imaging in the baboon, the large-scale neural network involved in visual recognition memory in the nonhuman primate was mapped for the first time. In this method, the tracer is injected in the awake, unanesthetized, and unrestrained baboon performing the memory task, and brain imaging is performed later under light anesthesia. Brain maps obtained during a computerized trial-unique delayed matching-to-sample task (lists of meaningless geometrical patterns and delay > 9 seconds) were statistically compared pixel-by-pixel to maps obtained during a specially designed visuomotor control task. When displayed onto the baboon's own anatomic magnetic resonance images, foci of significant activation were distributed along the ventral occipitotemporal pathway, the inferomedial temporal lobe (especially the perirhinal cortex and posterior hippocampal region), and the orbitofrontal cortex, consistent with lesion, single-unit, and autoradiographic studies in monkeys, as well as with activation studies in healthy humans. Additional activated regions included the nucleus basalis of Meynert, the globus pallidus and the putamen. The results also document an unexpected left-sided advantage, suggesting hemispheric functional specialization for recognition of figural material in nonhuman primates.
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Toni, Ivan, Nadim J. Shah, Gereon R. Fink, Daniel Thoenissen, Richard E. Passingham, and Karl Zilles. "Multiple Movement Representations in the Human Brain: An Event-Related fMRI Study." Journal of Cognitive Neuroscience 14, no. 5 (July 1, 2002): 769–84. http://dx.doi.org/10.1162/08989290260138663.
Full textAbstract:
Neurovascular correlates of response preparation have been investigated in human neuroimaging studies. However, conventional neuroimaging cannot distinguish, within the same trial, between areas involved in response selection and/ or response execution and areas specifically involved in response preparation. The specific contribution of parietal and frontal areas to motor preparation has been explored in electrophysiological studies in monkey. However, the associative nature of sensorimotor tasks calls for the additional contributions of other cortical regions. In this article, we have investigated the functional anatomy of movement representations in the context of an associative visuomotor task with instructed delays. Neural correlates of movement representations have been assessed by isolating preparatory activity that is independent from the performance of an actual motor act, or from the presence of a response's target. Movement instruction (specified by visual cues) and motor performance (specified by an auditory cue) were separated by a variable delay period. We have used whole-brain event-related fMRI to measure human brain activity during the performance of such a task. We have focused our analysis on specific preparatory activity, defined as a sustained response over variable delay periods between a transient visual instruction cue and a brief motor response, temporally independent from the transient events. Behavioral and electrophysiological controls ensured that preparatory activity was not contaminated by overt motor responses or working memory processes. We report suggestive evidence for multiple movement representations in the human brain. Specific sustained activity in preparation for an action was found not only in parieto-frontal regions but also in extrastriate areas and in the posterior portion of the superior temporal sulcus. We suggest that goal-directed preparatory activity relies on both visuo-motor and visuoperceptual areas. These findings point to a functional anatomical basis for the integration of perceptual and executive processes.
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White, Brian J., Jan Theeuwes, and Douglas P. Munoz. "Interaction between Visual- and Goal-related Neuronal Signals on the Trajectories of Saccadic Eye Movements." Journal of Cognitive Neuroscience 24, no. 3 (March 2012): 707–17. http://dx.doi.org/10.1162/jocn_a_00162.
Full textAbstract:
During natural viewing, the trajectories of saccadic eye movements often deviate dramatically from a straight-line path between objects. In human studies, saccades have been shown to deviate toward or away from salient visual distractors depending on visual- and goal-related parameters, but the neurophysiological basis for this is not well understood. Some studies suggest that deviation toward is associated with competition between simultaneously active sites within the intermediate layers of the superior colliculus (SC), a midbrain structure that integrates sensory and goal-related signals for the production of saccades. In contrast, deviation away is hypothesized to reflect a higher-level process, whereby the neural site associated with the distractor isactively suppressed via a form of endogenous, top–down inhibition. We tested this hypothesis by measuring presaccadic distractor-evoked activation of SC visuomotor neurons while monkeys performed a simple task configured specifically to induce a high degree of saccades that deviate away. In the SC, cognitive processes such as top–down expectation are represented as variation in the sustained, low-frequency presaccadic discharge. We reasoned that any inhibition at the distractor-related locus associated with saccade deviation should affect the excitability of the neuron, thereby affecting the discharge rate. We found that, although the task produced robust deviation away, there was no evidence of a relationship between saccade deviation and distractor-evoked activation outside a short perisaccadic window that began no earlier than 22 msec before saccade onset. This indicates that deviation away is not adequately explained by a form of sustained, top–down inhibition at the distractor-related locus in the SC. The results are discussed in relation to the primary sources of inhibition associated with saccadic control.
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Waitzman, D. M., V. L. Silakov, and B. Cohen. "Central mesencephalic reticular formation (cMRF) neurons discharging before and during eye movements." Journal of Neurophysiology 75, no. 4 (April 1, 1996): 1546–72. http://dx.doi.org/10.1152/jn.1996.75.4.1546.
Full textAbstract:
1. One hundred twenty neurons were recorded in the central mesencephalic reticular formation (cMRF) of four rhesus monkeys, trained to make visually guided and targeted saccadic eye movements. Eye movements were recorded with the head fixed, using electrooculography (EOG) or subconjunctival scleral search coils. Seventy-six percent (92/120) of cells discharged before and during contraversive visually guided or targeted rapid eye movements, and 76% of these (70/92) responded during contraversive spontaneous saccades in the dark. cMRF neurons had large contraversive movement fields and either a high (> 10 spikes/s) or low background level of spontaneous activity in the dark. The optimal movement vectors (i.e., saccades with greatest response) were predominantly horizontal, although many had a vertical component. Cells with optimal movement vectors within +/- 25 degrees of pure vertical were more rostral in the MRF and were excluded from the analysis. 2. A subgroup of cMRF neurons (31 of 92) that discharged before and during visually guided saccades were examined for visual sensitivity. Slightly less than one-half of these cells (42%, 13/31) were visuomotor units, i.e., they responded to visual targets in the absence of eye movement. The other 58% (n = 18) did not discharge during the visual probe trial; they were movement-related cells. 3. Microstimulation (threshold 40-60 microA at 333 Hz) at the sites of many of these cMRF neurons produced contraversive saccadic eye movements at short latency (< 40 ms). The amplitude and direction of the elicited saccades were similar to the optimal movement vector determined from single-unit recording. This suggested that cMRF cells recorded at the same locus of electrical microstimulation participated in the network responsible for the production and control of rapid eye movements. 4. The 92 saccade-related neurons were divided into two groups on the basis of their background discharge rate. Firing rates for both low background (28%, n = 26) and high background (72%, n = 66) cells increased approximately 30 ms before contraversive saccades and reached a peak discharge just before saccade onset. The low background neurons had either no activity or generated a few spikes just before the end of ipsiversive saccades. The steady rate of discharge (> 10 spikes/s) of high background neurons was inhibited from approximately 20 ms before ipsiversive saccades until just before saccade end. 5. Cells were also subdivided on the basis of how their discharge rates fell at the end of saccades. Clipped cells (38%, n = 35) had activity that fell sharply with saccade offset. Partially clipped cells (62%, n = 57) had persistent firing in the 100 ms following the saccade that was > 20% higher than the firing during the 100 ms before the saccade. 6. Latencies between the 90% point on the rising edge of the peak discharge and the start of the saccade were < or = 5.3 ms for eye movement-related cells in two monkeys. Longer latencies (11-19 ms) were found when measured between the 10% point on the rising edge of the peak discharge and saccade onset. These latencies were equal to or shorter than those obtained for eye movement-related burst neurons in the intermediate and deep layers of the superior colliculus analyzed similarly. Delays between the peak discharge and peak eye velocity were 13.6-15.1 ms for the same group of cMRF eye movement-related cells. These were significantly shorter than the delays measured for eye movement neurons in the superior colliculus (SC) of one of the monkeys. These findings suggest that the buildup discharge of cMRF neurons occurs early enough before saccades to contribute to saccade triggering. The peak discharge, however, occurs with or after the burst in the SC, suggesting that this portion of the discharge serves a function other than saccade triggering. 7. The number of spikes in bursts associated with eye movement was correlated with saccade parameters.
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Maltempo, Teresa, Sabrina Pitzalis, Martina Bellagamba, Sara Di Marco, Patrizia Fattori, Gaspare Galati, Claudio Galletti, and Valentina Sulpizio. "Lower visual field preference for the visuomotor control of limb movements in the human dorsomedial parietal cortex." Brain Structure and Function, March 18, 2021. http://dx.doi.org/10.1007/s00429-021-02254-3.
Full textAbstract:
AbstractVisual cues coming from the lower visual field (VF) play an important role in the visual guidance of upper and lower limb movements. A recently described region situated in the dorsomedial parietal cortex, area hPEc (Pitzalis et al. in NeuroImage 202:116092, 2019), might have a role in integrating visually derived information with somatomotor signals to guide limb interaction with the environment. In macaque, it has been demonstrated that PEc receives visual information mostly from the lower visual field but, to date, there has been no systematic investigation of VF preference in the newly defined human homologue of macaque area PEc (hPEc). Here we examined the VF preferences of hPEc while participants performed a visuomotor task implying spatially directed delayed eye-, hand- and foot-movements towards different spatial locations within the VF. By analyzing data as a function of the different target locations towards which upcoming movements were planned (and then executed), we observed the presence of asymmetry in the vertical dimension of VF in area hPEc, being this area more strongly activated by limb movements directed towards visual targets located in the lower compared to the upper VF. This result confirms the view, first advanced in macaque monkey, that PEc is involved in processing visual information to guide body interaction with the external environment, including locomotion. We also observed a contralateral dominance for the lower VF preference in the foot selective somatomotor cortex anterior to hPEc. This result might reflect the role of this cortex (which includes areas PE and S-I) in providing highly topographically organized signals, likely useful to achieve an appropriate foot posture during locomotion.