Effects of Early Monocular Deprivation on Visual
... normal, monocularly deprived (MD), and binocularly deprived (BD) cats have demonstrated that cells of the striate cortex developed permanently abnormal receptivefield properties in the deprived cats. For instance, they reported that most cells in the normal cat’s striate cortex had receptive fields ...
... normal, monocularly deprived (MD), and binocularly deprived (BD) cats have demonstrated that cells of the striate cortex developed permanently abnormal receptivefield properties in the deprived cats. For instance, they reported that most cells in the normal cat’s striate cortex had receptive fields ...
An EM Study of the Dorsal Nucleus of the Lateral Lemniscus
... axonal endings after axonal transport of )H-labeled amino acids (Salpeter et al., 1977; Oliver, 1985). The areas of DNLL to be examined at the EM level were selected from the regions with heavy labeling in LM autoradiographs (Fig. 1, A, C, E). The 100-pm-thick section was trimmed for EM, while semit ...
... axonal endings after axonal transport of )H-labeled amino acids (Salpeter et al., 1977; Oliver, 1985). The areas of DNLL to be examined at the EM level were selected from the regions with heavy labeling in LM autoradiographs (Fig. 1, A, C, E). The 100-pm-thick section was trimmed for EM, while semit ...
Response characteristics of neurons in the pulvinar of awake cats to
... ing saccades but not to visual stimulation (n=27, 16% of characterized neurons; S neurons), second, neurons that responded to visual stimuli but not during saccades (n=86, 51% of characterized neurons; V neurons), and third, neurons that responded during saccades and to visual stimuli (n=53, 31% of ...
... ing saccades but not to visual stimulation (n=27, 16% of characterized neurons; S neurons), second, neurons that responded to visual stimuli but not during saccades (n=86, 51% of characterized neurons; V neurons), and third, neurons that responded during saccades and to visual stimuli (n=53, 31% of ...
The Nervous System Introduction Organization of Neural Tissue
... • Primary motor cortex – Most of the neurons here control muscles with the most precise motor control – the face, tongue, and hands – Individual neurons must work together to coordinate ...
... • Primary motor cortex – Most of the neurons here control muscles with the most precise motor control – the face, tongue, and hands – Individual neurons must work together to coordinate ...
The evolution of brains from early mammals to humans
... hippocampus, are enlarged and have many more neurons. Yet, structurally they resemble the lateral and medial cortical regions of reptiles. Dorsal cortex, now called neocortex, is not completely new, as the name suggests, but dorsal cortex has been transformed into a thick structure that is tradition ...
... hippocampus, are enlarged and have many more neurons. Yet, structurally they resemble the lateral and medial cortical regions of reptiles. Dorsal cortex, now called neocortex, is not completely new, as the name suggests, but dorsal cortex has been transformed into a thick structure that is tradition ...
The posterior parietal cortex: Sensorimotor interface for the planning
... leftmost column shows 3 neurons that encode target and hand position separably, in eye coordinates. Each cell is tuned for a target location in the upper visual field but one responds to rightward position (the top cell), another center, and the third leftward (bottom cell). These cells are also tun ...
... leftmost column shows 3 neurons that encode target and hand position separably, in eye coordinates. Each cell is tuned for a target location in the upper visual field but one responds to rightward position (the top cell), another center, and the third leftward (bottom cell). These cells are also tun ...
Functional Properties of Corticotectal Neurons in the Monkey`s
... and Goldberg in awake behaving monkeys had some form of activity that preceded visually guided saccadic eye movements, including a range of neuron activity from purely visual to purely movement related. It is clear there are signals in the frontal eye field that could drive saccadic eye movements an ...
... and Goldberg in awake behaving monkeys had some form of activity that preceded visually guided saccadic eye movements, including a range of neuron activity from purely visual to purely movement related. It is clear there are signals in the frontal eye field that could drive saccadic eye movements an ...
Saccadic Eye Movements Modulate Visual Responses in the Lateral
... to salient regions of the visual scene and allow examination of these areas with high acuity. However, eye movements also pose a significant challenge to the visual system; with every saccade, an image of the world moves abruptly over the retina, stimulating all of its ganglion cells in concert. If ...
... to salient regions of the visual scene and allow examination of these areas with high acuity. However, eye movements also pose a significant challenge to the visual system; with every saccade, an image of the world moves abruptly over the retina, stimulating all of its ganglion cells in concert. If ...
Saccade-induced activity of dorsal lateral geniculate nucleus X
... inhibited during saccades whereas the remaining X-cells showed excitatory responses (Fischer et al., 1996). A comparison of neuronal responses induced by saccade-like stimulus shifts while the eye was stationary, with actual saccade-evoked responses revealed that the latter had shorter latencies. Fr ...
... inhibited during saccades whereas the remaining X-cells showed excitatory responses (Fischer et al., 1996). A comparison of neuronal responses induced by saccade-like stimulus shifts while the eye was stationary, with actual saccade-evoked responses revealed that the latter had shorter latencies. Fr ...
Visual detection deficits following inactivation of the superior colliculus in the cat
... et al., 1982; Overton & Dean, 1988; Lomber et al., 2001). Unfortunately, the interpretation of these studies is limited because of one or more of the following considerations: (1) Most of these experiments used permanent ablation of the SC rather than reversible inactivation. SC ablation initially p ...
... et al., 1982; Overton & Dean, 1988; Lomber et al., 2001). Unfortunately, the interpretation of these studies is limited because of one or more of the following considerations: (1) Most of these experiments used permanent ablation of the SC rather than reversible inactivation. SC ablation initially p ...
"Visual System Development in Vertebrates". In: Encyclopedia of
... distinct functions and make specific patterns of synaptic connections. Thus, photoreceptors consist of both rods and cones that differ in their sensitivity to light, morphology and distribution in the retina. Moreover, at least 15 different subtypes of RGCs, as well as multiple types of amacrine and bi ...
... distinct functions and make specific patterns of synaptic connections. Thus, photoreceptors consist of both rods and cones that differ in their sensitivity to light, morphology and distribution in the retina. Moreover, at least 15 different subtypes of RGCs, as well as multiple types of amacrine and bi ...
Deciphering a neural code for vision
... recorded firing rate by using the method of least squares and then normalizing the result with the contrast of the stimulus. ...
... recorded firing rate by using the method of least squares and then normalizing the result with the contrast of the stimulus. ...
Caudal Topographic Nucleus Isthmi and the Rostra1
... neurons labeled in Imr, nucleus lentiformis mesencephali, or profundus mesencephali rostralis (PMr). The axons of neurons in those nuclei were reconstructed from serial sections and found to branch widely, sparsely innervating large areas of the tectum. Fourth, the dense thickets are not terminals o ...
... neurons labeled in Imr, nucleus lentiformis mesencephali, or profundus mesencephali rostralis (PMr). The axons of neurons in those nuclei were reconstructed from serial sections and found to branch widely, sparsely innervating large areas of the tectum. Fourth, the dense thickets are not terminals o ...
Expectation of reward modulates cognitive signals in the basal ganglia
... (data points close to the ordinate) or a reduction (data points close to the abscissa) of response by expectation of reward (Fig. 5a). A statistically significant modulation was found in 76 of 87 neurons (87%) in visual or memoryrelated responses: visual response, 36/45 (80%); memory response, 43/50 ...
... (data points close to the ordinate) or a reduction (data points close to the abscissa) of response by expectation of reward (Fig. 5a). A statistically significant modulation was found in 76 of 87 neurons (87%) in visual or memoryrelated responses: visual response, 36/45 (80%); memory response, 43/50 ...
Contextual Modulation of Substantia Nigra Pars Reticulata Neurons
... 3042–3048, 2000. Neurons in the substantia nigra pars reticulata (SNr) are known to encode saccadic eye movements within some, but not all, behavioral contexts. However, the precise contextual factors that effect the modulations of nigral activity are still uncertain. To further examine the effect o ...
... 3042–3048, 2000. Neurons in the substantia nigra pars reticulata (SNr) are known to encode saccadic eye movements within some, but not all, behavioral contexts. However, the precise contextual factors that effect the modulations of nigral activity are still uncertain. To further examine the effect o ...
Branched thalamic afferents - the Sherman Lab
... branches, may apply to homeotherms but not to poikilotherms. That is an open question but since we are dealing with afferents to the thalamus, which is strongly developed in homeotherms, this point may be important. It is possible that branched axons in mammals can perform in ways that those of our ...
... branches, may apply to homeotherms but not to poikilotherms. That is an open question but since we are dealing with afferents to the thalamus, which is strongly developed in homeotherms, this point may be important. It is possible that branched axons in mammals can perform in ways that those of our ...
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... of neurons. During early stages of circuit development, genetically specified molecular signals appear to guide such processes as axonal outgrowth and targeting. However, these early connections are typically diffuse and imprecise. Adult patterns of connectivity subsequently emerge by a process of r ...
... of neurons. During early stages of circuit development, genetically specified molecular signals appear to guide such processes as axonal outgrowth and targeting. However, these early connections are typically diffuse and imprecise. Adult patterns of connectivity subsequently emerge by a process of r ...
Primary Visual Pathway
... of on and off zones • Length cells - respond to length of a bar that was moved across a receptive field • Direction cells - respond to direction of a bar moving across the receptive field. ...
... of on and off zones • Length cells - respond to length of a bar that was moved across a receptive field • Direction cells - respond to direction of a bar moving across the receptive field. ...
Loss of Neurons in Magnocellular and Parvocellular Layers of the
... layers 1 and 2 are magnocellular layers, while the remaining dorsal layers 3 through 6 are parvocellular layers. Layers 1, 4, and 6 of the left LGN are connected to the glaucomatous right eye, while layers 2, 3, and 5 are connected to the nonglaucomatous left eye. To determine whether neurons are lo ...
... layers 1 and 2 are magnocellular layers, while the remaining dorsal layers 3 through 6 are parvocellular layers. Layers 1, 4, and 6 of the left LGN are connected to the glaucomatous right eye, while layers 2, 3, and 5 are connected to the nonglaucomatous left eye. To determine whether neurons are lo ...
Brainstem
... - involved in visual reflex and eye movement - inputs -- from cerebral cortex (visual areas ) : corticocollicular fibers -- from retina -- from spinal cord : ascend with spinothalamic tract -- from inferior colliculus : eye and head are turned toward the source of a sound - outputs : -- to spinal co ...
... - involved in visual reflex and eye movement - inputs -- from cerebral cortex (visual areas ) : corticocollicular fibers -- from retina -- from spinal cord : ascend with spinothalamic tract -- from inferior colliculus : eye and head are turned toward the source of a sound - outputs : -- to spinal co ...
안구의 내하방 편위 - Research in Vestibular Science
... compressing the midbrain. Two patients showed multiple infarctions in the territory of the posterior circulation with or without the involvement of the thalamus. Another patient had lateral pontine hemorrhage extending up to the midbrain tegmentum. Ocular bobbing preceded or accompanied tonic ocular ...
... compressing the midbrain. Two patients showed multiple infarctions in the territory of the posterior circulation with or without the involvement of the thalamus. Another patient had lateral pontine hemorrhage extending up to the midbrain tegmentum. Ocular bobbing preceded or accompanied tonic ocular ...
The Dorsal Visual System Predicts Future and Remembers Past Eye
... be updated long before (<100 ms) or after (<200 ms) an eye movement. The results suggest a flexible coding scheme in which downstream computations have access to past, current, and future eye positions simultaneously, providing a basis for visual stability and delay-free visually-guided behavior. Ke ...
... be updated long before (<100 ms) or after (<200 ms) an eye movement. The results suggest a flexible coding scheme in which downstream computations have access to past, current, and future eye positions simultaneously, providing a basis for visual stability and delay-free visually-guided behavior. Ke ...
cerebral cortex, sensations and movements
... Specific maps of these areas involve higher regions of the cortex devoted to the lower parts of the body (ex. toes) and lower regions of the cortex devoted to the upper body (ex. the head). Therefore, the arrangement of cortical nervous centers is disposed as a motor or sensory homunculus upside dow ...
... Specific maps of these areas involve higher regions of the cortex devoted to the lower parts of the body (ex. toes) and lower regions of the cortex devoted to the upper body (ex. the head). Therefore, the arrangement of cortical nervous centers is disposed as a motor or sensory homunculus upside dow ...
Visual and oculomotor selection: links, causes and
... visual responses in V4 neurons at retinotopically corresponding locations, whereas responses at other locations were suppressed. Interestingly, both the enhancement and suppression effects depended on the presence of additional ‘distracter’ stimuli outside the V4 neuron receptive field, as has been ...
... visual responses in V4 neurons at retinotopically corresponding locations, whereas responses at other locations were suppressed. Interestingly, both the enhancement and suppression effects depended on the presence of additional ‘distracter’ stimuli outside the V4 neuron receptive field, as has been ...
Sensory experience and the formation of a computational map of
... localization cue also takes place to a large extent within separate, parallel pathways in the mammalian brainstem.(19) ITDs and ILDs are processed primarily in the medial and lateral divisions of the superior olivary complex, respectively. However, in contrast to barn owls, these binaural cues are u ...
... localization cue also takes place to a large extent within separate, parallel pathways in the mammalian brainstem.(19) ITDs and ILDs are processed primarily in the medial and lateral divisions of the superior olivary complex, respectively. However, in contrast to barn owls, these binaural cues are u ...
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.