Mapping Retinotopic Structure in Mouse Visual Cortex with Optical
... signal across all imaged single-condition maps and aligned the resulting map with both cytochrome oxidase-stained and SMI32-stained (Duffy et al., 1998) sections using the superficial blood vessels as landmarks (Fig. 1 E, top panels). Both the size and shape of the imaged and the stained areas are i ...
... signal across all imaged single-condition maps and aligned the resulting map with both cytochrome oxidase-stained and SMI32-stained (Duffy et al., 1998) sections using the superficial blood vessels as landmarks (Fig. 1 E, top panels). Both the size and shape of the imaged and the stained areas are i ...
pdf file. - Harvard Vision Lab
... analysing sensory input. One way in which the brain keeps track of self-movement is by monitoring an internal copy, or corollary discharge, of motor commands1–13. This concept could explain why we perceive a stable visual world despite our frequent quick, or saccadic, eye movements: corollary discha ...
... analysing sensory input. One way in which the brain keeps track of self-movement is by monitoring an internal copy, or corollary discharge, of motor commands1–13. This concept could explain why we perceive a stable visual world despite our frequent quick, or saccadic, eye movements: corollary discha ...
Simulating the Fröhlich Effect of Motion Misperception as a Result... Attentional Modulation in the Visual System
... gravity and thereby mapped stimulus positions to locations in V1. The current center of gravity is compared to these reference values and the most similar one is taken as the network’s “perceived” starting location. These processes generate the Fröhlich effect because the activity pattern inside the ...
... gravity and thereby mapped stimulus positions to locations in V1. The current center of gravity is compared to these reference values and the most similar one is taken as the network’s “perceived” starting location. These processes generate the Fröhlich effect because the activity pattern inside the ...
Data Visualization Optimization Computational Modeling of Perception
... This Gabor function is a good approximation of the edge patterns for which V1 neurons are selective [31]. Daugman argued that this function provides an optimal tradeoff between representing spatial position and frequency. Previous models of the human visual system have produced the contour perceptio ...
... This Gabor function is a good approximation of the edge patterns for which V1 neurons are selective [31]. Daugman argued that this function provides an optimal tradeoff between representing spatial position and frequency. Previous models of the human visual system have produced the contour perceptio ...
The representation of Kanizsa illusory contours in the monkey
... are called illusory (or subjective) contours. Illusory and real contours activate early stages of the macaque visual pathway in similar ways. However, data relating to the processing of illusory contours in higher visual areas are scarce. We recently reported how illusory contours based on abutting- ...
... are called illusory (or subjective) contours. Illusory and real contours activate early stages of the macaque visual pathway in similar ways. However, data relating to the processing of illusory contours in higher visual areas are scarce. We recently reported how illusory contours based on abutting- ...
Visual Experience Is Necessary for Maintenance But Not
... throughout postnatal development can also result in enlarged cortical RFs, as defined electrophysiologically (Fagiolini et al. 1994). An alternative explanation for these results, however, is that the enlarged RFs in deprived animals result not from preservation of an early, unrefined state, but fro ...
... throughout postnatal development can also result in enlarged cortical RFs, as defined electrophysiologically (Fagiolini et al. 1994). An alternative explanation for these results, however, is that the enlarged RFs in deprived animals result not from preservation of an early, unrefined state, but fro ...
What insights can fMRI offer into the structure and function of mid-tier visual areas?
... the sub-populations of neurons. Brouwer and Heeger took advantage of the fact that—for whatever reason—each fMRI voxel in V1 has a slight orientation bias (Kamitani & Tong, 2005; Sun et al., 2013). Using these biased voxels as indicators of the underlying neural subpopulations, they were able to est ...
... the sub-populations of neurons. Brouwer and Heeger took advantage of the fact that—for whatever reason—each fMRI voxel in V1 has a slight orientation bias (Kamitani & Tong, 2005; Sun et al., 2013). Using these biased voxels as indicators of the underlying neural subpopulations, they were able to est ...
Reduced BOLD response to periodic visual stimulation
... course, repetitive aperiodic stimulation will also produce synchronous firing with a frequency profile reflecting that of the stimulus. However, periodic stimulation also produces entrainment, where the bursts of firing increase in amplitude over the first few hundred milliseconds of stimulation, an ...
... course, repetitive aperiodic stimulation will also produce synchronous firing with a frequency profile reflecting that of the stimulus. However, periodic stimulation also produces entrainment, where the bursts of firing increase in amplitude over the first few hundred milliseconds of stimulation, an ...
What can mice tell us about how vision works?
... Understanding how the brain gives rise to the experience of sight is an important and fundamental question that has garnered much attention over the years [1]. The longstanding emphasis stems from the fact that many mammals, including humans, rely on vision as their primary sense to evaluate their s ...
... Understanding how the brain gives rise to the experience of sight is an important and fundamental question that has garnered much attention over the years [1]. The longstanding emphasis stems from the fact that many mammals, including humans, rely on vision as their primary sense to evaluate their s ...
The time course of selective visual attention: theory and experiments
... with different features. This would be the same for all the features comprising the stimuli: colour, shape, location, etc. This process of feature selection suggests that subjects utilize top-down information (from the template) independent of localisation of the stimuli in space. The attentional the ...
... with different features. This would be the same for all the features comprising the stimuli: colour, shape, location, etc. This process of feature selection suggests that subjects utilize top-down information (from the template) independent of localisation of the stimuli in space. The attentional the ...
contextual influences on visual processing
... whether the frequency modulation was high-to-low or low-to-high). Although this finding would offer an interesting (and perhaps satisfyingly parametric) link between single neurons and perceptual decisions, it seems clear that stimuli constructed of words and sentences would yield results more likel ...
... whether the frequency modulation was high-to-low or low-to-high). Although this finding would offer an interesting (and perhaps satisfyingly parametric) link between single neurons and perceptual decisions, it seems clear that stimuli constructed of words and sentences would yield results more likel ...
Role of Feedforward and Feedback Projections in Figure
... modified by factors such as experience and learning, or, more importantly, by the spatial and temporal context in which a stimulus is presented. The latter strongly influences the stimulus evoked response of a cell. The prominence of contextual information processing is reflected by the fact that th ...
... modified by factors such as experience and learning, or, more importantly, by the spatial and temporal context in which a stimulus is presented. The latter strongly influences the stimulus evoked response of a cell. The prominence of contextual information processing is reflected by the fact that th ...
weiten6_PPT04
... Form perception - top-down processing Subjective contours Gestalt psychologists: the whole is more than the sum of its parts – Reversible figures and perceptual sets demonstrate that the same visual stimulus can result in very different perceptions Table of Contents ...
... Form perception - top-down processing Subjective contours Gestalt psychologists: the whole is more than the sum of its parts – Reversible figures and perceptual sets demonstrate that the same visual stimulus can result in very different perceptions Table of Contents ...
Multisensory contributions to low-level, `unisensory` processing
... cortex with this widespread network of areas, use of the full range of feedforward, feedback and lateral connection types appears likely. The visual inputs to audiovisual interactions that are believed to occur in auditory cortex [3,5,7,25], similar to the somatosensory inputs discussed above, could ...
... cortex with this widespread network of areas, use of the full range of feedforward, feedback and lateral connection types appears likely. The visual inputs to audiovisual interactions that are believed to occur in auditory cortex [3,5,7,25], similar to the somatosensory inputs discussed above, could ...
pdf - Olin Neuropsychiatry Research Center
... network of limbic, paralimbic, and association areas supports the goal-directed processing of task-relevant target events. In that paradigm, greater activity in diverse brain areas is elicited by rare task-relevant events that require a subsequent motor response than by rare taskirrelevant novel eve ...
... network of limbic, paralimbic, and association areas supports the goal-directed processing of task-relevant target events. In that paradigm, greater activity in diverse brain areas is elicited by rare task-relevant events that require a subsequent motor response than by rare taskirrelevant novel eve ...
Is neocortex essentially multisensory?
... the inactivation does not impair orientation to unimodally presented targets [37]. Based on these data, it is clear that association cortical areas have an important role to play in multimodally driven behaviours. Nevertheless, for many behaviors (if not all) and contexts, synthesis of information f ...
... the inactivation does not impair orientation to unimodally presented targets [37]. Based on these data, it is clear that association cortical areas have an important role to play in multimodally driven behaviours. Nevertheless, for many behaviors (if not all) and contexts, synthesis of information f ...
Transcripts/2_4 1
... i. By far the biggest part of our visual system is computation. ii. Something like 1/3 or 1/4 of the human brain is required for our full visual capability. That is an enormous amount of tissue, which is more than for language. iii. Why is this? Why does visual processing take so much of the brain? ...
... i. By far the biggest part of our visual system is computation. ii. Something like 1/3 or 1/4 of the human brain is required for our full visual capability. That is an enormous amount of tissue, which is more than for language. iii. Why is this? Why does visual processing take so much of the brain? ...
Hippocampus duality: memory and novelty detection are subserved
... brain region is apparently responsible both for detecting out-of-context stimuli and also for matching stimuli in the environment to stored representations. Each of these aspects of cognition is associated with frequently used experimental paradigms and robust electrophysiological signatures, but th ...
... brain region is apparently responsible both for detecting out-of-context stimuli and also for matching stimuli in the environment to stored representations. Each of these aspects of cognition is associated with frequently used experimental paradigms and robust electrophysiological signatures, but th ...
A Dynamic Field Theory of Visual Recognition in Infant Looking... Gregor Schöner Sammy Perone () and John P. Spencer ()
... only difference across simulations was in the distribution of the inputs. Mareschal and colleagues (e.g., Mareschal, French, & Quinn, 2000; French et al., 2004) have extensively examined the role of input distribution in asymmetric categorization and have tested predictions of an autoencoder network ...
... only difference across simulations was in the distribution of the inputs. Mareschal and colleagues (e.g., Mareschal, French, & Quinn, 2000; French et al., 2004) have extensively examined the role of input distribution in asymmetric categorization and have tested predictions of an autoencoder network ...
Cross-Modal Transfer of Information between the Tactile
... there is no polysensory cross-modal area, no cross-modal region “in which representations formed in one sense would reside and be accessed by another sense,” but suggested instead a system in which the senses can access each other directly from their sensory-specific systems. For the present purpose ...
... there is no polysensory cross-modal area, no cross-modal region “in which representations formed in one sense would reside and be accessed by another sense,” but suggested instead a system in which the senses can access each other directly from their sensory-specific systems. For the present purpose ...
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... The decision where to move the eyes seems to be more a function of low level factors such as word length. However, explaining exactly how the brain controls eye movements in reading is no easy task, given the speed at which several complex processes are being executed (for review see Rayner et al, 2 ...
... The decision where to move the eyes seems to be more a function of low level factors such as word length. However, explaining exactly how the brain controls eye movements in reading is no easy task, given the speed at which several complex processes are being executed (for review see Rayner et al, 2 ...
Visual areas and spatial summation in human visual cortex
... Functional MRI measurements can securely partition the human posterior occipital lobe into retinotopically organized visual areas (V1, V2 and V3) with experiments that last only 30 min. Methods for identifying functional areas in the dorsal and ventral aspect of the human occipital cortex, however, ...
... Functional MRI measurements can securely partition the human posterior occipital lobe into retinotopically organized visual areas (V1, V2 and V3) with experiments that last only 30 min. Methods for identifying functional areas in the dorsal and ventral aspect of the human occipital cortex, however, ...
Anatomical Evidence of Multimodal Integration in Primate
... Injections of tracers. Thirteen retrograde tracing experiments were performed on nine cynomolgus monkeys (Macaca fascicularis; Table 1). After premedication with atropine (1.25 mg, i.m.) and dexamethasone (4 mg, i.m.), monkeys were prepared for surgery under ketamine hydrochloride (20 mg / kg, i.m.) ...
... Injections of tracers. Thirteen retrograde tracing experiments were performed on nine cynomolgus monkeys (Macaca fascicularis; Table 1). After premedication with atropine (1.25 mg, i.m.) and dexamethasone (4 mg, i.m.), monkeys were prepared for surgery under ketamine hydrochloride (20 mg / kg, i.m.) ...
Review The Neural Basis of Perceptual Learning
... encode more complex stimulus features, that such features can be encoded at earlier stages in sensory processing, or some combination of the two. The dependence of learning on position and orientation, which argues for the involvement of early cortical stages in visual processing, may seem to confli ...
... encode more complex stimulus features, that such features can be encoded at earlier stages in sensory processing, or some combination of the two. The dependence of learning on position and orientation, which argues for the involvement of early cortical stages in visual processing, may seem to confli ...
High-Level Visual Processing: Cognitive Influences
... selectivities often appear somewhat arbitrary. An individual neuron might, for example, respond strongly to a crescent-shaped pattern of a particular color and texture. Cells with such unique selectivities likely provide inputs to yet higher-order neuronal representations of meaningful objects. Inde ...
... selectivities often appear somewhat arbitrary. An individual neuron might, for example, respond strongly to a crescent-shaped pattern of a particular color and texture. Cells with such unique selectivities likely provide inputs to yet higher-order neuronal representations of meaningful objects. Inde ...
P200
In neuroscience, the visual P200 or P2 is a waveform component or feature of the event-related potential (ERP) measured at the human scalp. Like other potential changes measurable from the scalp, this effect is believed to reflect the post-synaptic activity of a specific neural process. The P2 component, also known as the P200, is so named because it is a positive going electrical potential that peaks at about 200 milliseconds (varying between about 150 and 275 ms) after the onset of some external stimulus . The distribution of this component in the brain, as measured by electrodes placed across the scalp, is located around the centro-frontal and the parieto-occipital region. It is generally found to be maximal around the vertex (frontal region) of the scalp, however there have been some topographical differences noted in ERP studies of the P2 in different experimental conditions.Research on the visual P2 is at an early stage compared to other more established ERP components and there is much that we still do not know about it. Part of the difficulty of clearly characterizing this component is that it appears to be modulated by a large and diverse number of cognitive tasks. Functionally, there seems to be partial agreement amongst researchers in the field of cognitive neuroscience that the P2 represents some aspect of higher-order perceptual processing, modulated by attention. It is known that the P2 is typically elicited as part of the normal response to visual stimuli and has been studied in relation to visual search and attention, language context information, and memory and repetition effects. The amplitude of the peak of the waveform may be modulated by many different aspects of visual stimuli, which allow it to be used for studies of visual cognition and disease. In general, the P2 may be a part of cognitive matching system that compares sensory inputs with stored memory.