Stimuluslocked responses on human arm muscles reveal a rapid
... extremely short latencies, implying the presence of a short-latency neural pathway linking visual input to limb motor output. However, little is known about the neural mechanisms that underlie such hastened arm responses. One clue may come from recent demonstrations that the appearance of a visual t ...
... extremely short latencies, implying the presence of a short-latency neural pathway linking visual input to limb motor output. However, little is known about the neural mechanisms that underlie such hastened arm responses. One clue may come from recent demonstrations that the appearance of a visual t ...
Torsten Wiesel - Biology Courses Server
... Fig. 3. Dark field autoradiographs of monkey striate cortex following injection of3 H-proline in the vitreous of one eye 2 weeks before. A: Normal monkey, a montage of a series of tangential sections through layer IVC. The light stripes, representing the labelled eye columns, are separated by gaps o ...
... Fig. 3. Dark field autoradiographs of monkey striate cortex following injection of3 H-proline in the vitreous of one eye 2 weeks before. A: Normal monkey, a montage of a series of tangential sections through layer IVC. The light stripes, representing the labelled eye columns, are separated by gaps o ...
Functional circuitry underlying visual neglect
... include mutually suppressive mechanisms between the two hemispheres, and we show that these mechanisms operate at the level of the SC, but are not apparent at the level of cortex. These results suggest that the most effective therapies for visual neglect will be those that act to decrease neural act ...
... include mutually suppressive mechanisms between the two hemispheres, and we show that these mechanisms operate at the level of the SC, but are not apparent at the level of cortex. These results suggest that the most effective therapies for visual neglect will be those that act to decrease neural act ...
development and plasticity of cortical areas and networks
... commences on embryonic day (E) 22. Progressively more superficial layers are generated over the following five weeks, with genesis of layers II/III not completed until postnatal day (P) 14; the exception to this is layer I, which is generated both early and late (not shown)163. A similar progression ...
... commences on embryonic day (E) 22. Progressively more superficial layers are generated over the following five weeks, with genesis of layers II/III not completed until postnatal day (P) 14; the exception to this is layer I, which is generated both early and late (not shown)163. A similar progression ...
Signals Conveyed in the Pulvinar Pathway from Superior Colliculus
... to the stimulated structure. It is worth noting that, although successful The fixation task (Fig. 2 A) was used to map visual receptive fields, to orthodromic/antidromic activation provides clear evidence of conneccompare visual responsivity under passive (fixation) versus active (sactivity, the fai ...
... to the stimulated structure. It is worth noting that, although successful The fixation task (Fig. 2 A) was used to map visual receptive fields, to orthodromic/antidromic activation provides clear evidence of conneccompare visual responsivity under passive (fixation) versus active (sactivity, the fai ...
development and plasticity of cortical areas and networks
... commences on embryonic day (E) 22. Progressively more superficial layers are generated over the following five weeks, with genesis of layers II/III not completed until postnatal day (P) 14; the exception to this is layer I, which is generated both early and late (not shown)163. A similar progression ...
... commences on embryonic day (E) 22. Progressively more superficial layers are generated over the following five weeks, with genesis of layers II/III not completed until postnatal day (P) 14; the exception to this is layer I, which is generated both early and late (not shown)163. A similar progression ...
Binocular vision, the optic chiasm, and their associations with
... cerebral hemisphere was the fundamental mechanism behind the OC evolution. In other words, that evolutionary change in the OC was necessary to preserve hemispheric autonomy. In the majority of vertebrates, motor processing, tactile, proprioceptive, and visual information involved in steering the han ...
... cerebral hemisphere was the fundamental mechanism behind the OC evolution. In other words, that evolutionary change in the OC was necessary to preserve hemispheric autonomy. In the majority of vertebrates, motor processing, tactile, proprioceptive, and visual information involved in steering the han ...
Primate Frontal Eye Fields. II. Physiological and Anatomical
... of two frontal eye field loci evokes a saccade that is approximately the mean of the characteristic saccades at the two sites (54). Although the phenomenology of these evoked saccades is well described, it has not been shown how, if at all, they are related to the functional physiology of this corte ...
... of two frontal eye field loci evokes a saccade that is approximately the mean of the characteristic saccades at the two sites (54). Although the phenomenology of these evoked saccades is well described, it has not been shown how, if at all, they are related to the functional physiology of this corte ...
Some Fiber Projections to the Superior Colliculus in the Cat`
... animals in the pretectum, though the number of degenerated fibers was considerably greater in those animals which had ventrally placed geniculate lesions. These degenerated fibers reached the pretectum by way of the medial aspect of the optic tract and the lateral and medial branches of the brachium ...
... animals in the pretectum, though the number of degenerated fibers was considerably greater in those animals which had ventrally placed geniculate lesions. These degenerated fibers reached the pretectum by way of the medial aspect of the optic tract and the lateral and medial branches of the brachium ...
The Distribution of Chandelier Cell Axon Terminals that Express the
... exclusively with the axon initial segments of pyramidal cells. In this study, we have used immunocytochemistry for the high-affinity plasma membrane transporter-1 (GAT-1) to analyze the distribution and density of Ch-terminals in various cytoarchitectonic and functional areas of the human neocortex. ...
... exclusively with the axon initial segments of pyramidal cells. In this study, we have used immunocytochemistry for the high-affinity plasma membrane transporter-1 (GAT-1) to analyze the distribution and density of Ch-terminals in various cytoarchitectonic and functional areas of the human neocortex. ...
Inferior Parietal Lobule Function in Spatial Perception and
... seen in humans with parietal lobe damage in whom accuracy is affected only for the spatial hemifield contralateral to the cortical lesion regardless of which limb is used. Stein (193), however, has demonstrated a reversible deficit in hand-eye tracking in monkeys that was confined to the contralater ...
... seen in humans with parietal lobe damage in whom accuracy is affected only for the spatial hemifield contralateral to the cortical lesion regardless of which limb is used. Stein (193), however, has demonstrated a reversible deficit in hand-eye tracking in monkeys that was confined to the contralater ...
~ Pergamon
... according to a method described previously. 6,~3 References to architectonic areas of the prefrontal cortex are according to a classification described previously/4 Areal measures and the number of diaphorase-positive neurons for superficial (layers I-III) and deep (layers IV VII) cortical layers, p ...
... according to a method described previously. 6,~3 References to architectonic areas of the prefrontal cortex are according to a classification described previously/4 Areal measures and the number of diaphorase-positive neurons for superficial (layers I-III) and deep (layers IV VII) cortical layers, p ...
Pupilllary Light Reflex Pathways
... The oculosympathetic pathway to the globe, orbit, and adnexal structures takes a long and convoluted course, and is therefore denervation (Horner syndrome) is associated with lesions in a variety of anatomic sites along this pathway. First order neurons arise in the hypothalamus and course down the ...
... The oculosympathetic pathway to the globe, orbit, and adnexal structures takes a long and convoluted course, and is therefore denervation (Horner syndrome) is associated with lesions in a variety of anatomic sites along this pathway. First order neurons arise in the hypothalamus and course down the ...
The Distribution of Immunoreactivity for
... estrogen (ER) and androgen receptors (AR) maintain. While clearly more abundant, however, less is known about the cortical distribution of intracellular AR as compared with ER proteins. Available evidence suggests, though, that at least in rats these two hormone pathways occupy distinct niches among ...
... estrogen (ER) and androgen receptors (AR) maintain. While clearly more abundant, however, less is known about the cortical distribution of intracellular AR as compared with ER proteins. Available evidence suggests, though, that at least in rats these two hormone pathways occupy distinct niches among ...
Prefrontal Neurons Coding Suppression of Specific Saccades
... lobe (e.g., Hasegawa et al., 1998, 2000a, 2004) in monkeys have dealt with the generation of movement rather than its suppression. The saccadic system provides an excellent model for the suppression of unwanted behavior. Monkeys as well as humans can voluntarily move their eyes not only to look at s ...
... lobe (e.g., Hasegawa et al., 1998, 2000a, 2004) in monkeys have dealt with the generation of movement rather than its suppression. The saccadic system provides an excellent model for the suppression of unwanted behavior. Monkeys as well as humans can voluntarily move their eyes not only to look at s ...
Heterotopic Transcallosal Projections Are Present throughout the
... located in layers II/III and to a lesser extent layer V of the cortex. Their axons form the corpus callosum thereby providing an inter-hemispheric connection in the brain. While transcallosal projection neurons have been described in some detail before, it is so far unclear whether they are uniforml ...
... located in layers II/III and to a lesser extent layer V of the cortex. Their axons form the corpus callosum thereby providing an inter-hemispheric connection in the brain. While transcallosal projection neurons have been described in some detail before, it is so far unclear whether they are uniforml ...
Self-Organizing Feature Maps with Lateral Connections: Modeling
... Much of its structure and connectivity depends on electrical activity during development. Because various neocortical areas are very similar in anatomical structure and exhibit similar developmental phenomena, it has been suggested that a common organizing mechanism underlies their ontogeny [18]. By ...
... Much of its structure and connectivity depends on electrical activity during development. Because various neocortical areas are very similar in anatomical structure and exhibit similar developmental phenomena, it has been suggested that a common organizing mechanism underlies their ontogeny [18]. By ...
Visual and presaccadic activity in area 8Ar of the macaque monkey
... fixation point (0.08 degrees2) and pressed a lever to indicate willingness to start the trial. After ...
... fixation point (0.08 degrees2) and pressed a lever to indicate willingness to start the trial. After ...
the properties and neural substrate of eye movements
... movements require both velocity-coded and position-coded changes in innervation, all conjugate eye movement commands need access to a common neural integrator. Experimental lesions of structures vital for neural integration affect all classes of conjugate eye movements.2,13 Furthermore, it appears t ...
... movements require both velocity-coded and position-coded changes in innervation, all conjugate eye movement commands need access to a common neural integrator. Experimental lesions of structures vital for neural integration affect all classes of conjugate eye movements.2,13 Furthermore, it appears t ...
Cortical control of saccades and fixation in man
... supplementary motor area (SMA), insula, cingulate, thalamus, midbrain, cerebellum and right superior temporal gyms (Brodmann s area 22). Compared with the individual saccadic tasks, central fixation activated extensive regions of ventromedial (areas 10, 11 and 32) and anterolateral (areas 8, 9, 10, ...
... supplementary motor area (SMA), insula, cingulate, thalamus, midbrain, cerebellum and right superior temporal gyms (Brodmann s area 22). Compared with the individual saccadic tasks, central fixation activated extensive regions of ventromedial (areas 10, 11 and 32) and anterolateral (areas 8, 9, 10, ...
Evolution of Vertebrate Brains - CIHR Group in Sensory
... The brains of living vertebrates are a reflection of the very diverse niches occupied by the different species that comprise each major taxon (Figure 1) – agnathans (jawless vertebrates) and three radiations of jawed vertebrates: (1) the cartilaginous fishes (chimaeras and sharks, skates, and rays), ...
... The brains of living vertebrates are a reflection of the very diverse niches occupied by the different species that comprise each major taxon (Figure 1) – agnathans (jawless vertebrates) and three radiations of jawed vertebrates: (1) the cartilaginous fishes (chimaeras and sharks, skates, and rays), ...
Gradual increase in neuronal density of rats
... primary structure that integrates visual information from the retina to the visual cortex in mammals.1 Light, which is converted into a chemical signal, is transmitted to the LGN,2 and then projected to the visual cortex by relay neurons in the LGN,3 which also receives cortical and subcortical affe ...
... primary structure that integrates visual information from the retina to the visual cortex in mammals.1 Light, which is converted into a chemical signal, is transmitted to the LGN,2 and then projected to the visual cortex by relay neurons in the LGN,3 which also receives cortical and subcortical affe ...
The functional asymmetry of auditory cortex is reflected
... inputs along the isofrequency axis (orthogonal to the tonotopic axis) arose predominantly within a column. By contrast, we found that local connections along the tonotopic axis differed from those along the isofrequency axis: some input pathways to L3 (but not L2) arose predominantly out-of-column. ...
... inputs along the isofrequency axis (orthogonal to the tonotopic axis) arose predominantly within a column. By contrast, we found that local connections along the tonotopic axis differed from those along the isofrequency axis: some input pathways to L3 (but not L2) arose predominantly out-of-column. ...
A Flow Chart For Classification Of Nystagmus
... velocity is higher when gaze is in the direction of the quick phase. With central lesions the opposite sometimes occurs. Nystagmus of peripheral origin is suppressed by visual fixation; nystagmus of a central origin is usually not. A dynamic imbalance between the response from the two labyrinths dur ...
... velocity is higher when gaze is in the direction of the quick phase. With central lesions the opposite sometimes occurs. Nystagmus of peripheral origin is suppressed by visual fixation; nystagmus of a central origin is usually not. A dynamic imbalance between the response from the two labyrinths dur ...
Limitations of Neural Map Topography for Decoding Spatial
... are equivalent to step functions in our one-dimensional model. To generate responses for decoding, we presented each stimulus to the model 50 times, for a total of 150 presentations. The response ri of each tectal cell to each presentation of each stimulus was recorded. Decoding was performed as des ...
... are equivalent to step functions in our one-dimensional model. To generate responses for decoding, we presented each stimulus to the model 50 times, for a total of 150 presentations. The response ri of each tectal cell to each presentation of each stimulus was recorded. Decoding was performed as des ...
Superior colliculus
The superior colliculus, (Latin, upper hill) is a paired structure of the mammalian midbrain. In other vertebrates this is known as the optic tectum or simply tectum, and the adjective tectal may also be used. The superior colliculus forms a major component of the midbrain. The tectum is a layered structure, with a number of layers that varies by species. The superficial layers are sensory-related, and receive input from the eyes as well as other sensory systems. The deep layers are motor-related, capable of activating eye movements as well as other responses. There are also intermediate layers, with multi-sensory cells and motor properties.The general function of the tectal system is to direct behavioral responses toward specific points in egocentric (""body-centered"") space. Each layer of the tectum contains a topographic map of the surrounding world in retinotopic coordinates, and activation of neurons at a particular point in the map evokes a response directed toward the corresponding point in space. In primates, the superior colliculus has been studied mainly with respect to its role in directing eye movements. Visual input from the retina, or ""command"" input from the cerebral cortex, create a ""bump"" of activity in the tectal map, which, if strong enough, induces a saccadic eye movement. Even in primates, however, the tectum is also involved in generating spatially directed head turns, arm-reaching movements, and shifts in attention that do not involve any overt movements. In other species, the tectum is involved in a wide range of responses, including whole-body turns in walking rats, swimming fishes, or flying birds; tongue-strikes toward prey in frogs; fang-strikes in snakes; etc.In some vertebrates, including fish and birds, the tectum is one of the largest components of the brain. In mammals, and especially primates, the massive expansion of the cerebral cortex reduces the tectum (""superior colliculus"") to a much smaller fraction of the whole brain. It remains nonetheless important in terms of function as the primary integrating center for eye movements.Note on terminology: This article follows terminology established in the literature for the analogous structure in mammals/non-mammals (see above), using the term ""superior colliculus"" when discussing mammals and ""optic tectum"" when discussing either specific non-mammalian species or vertebrates in general.