Computational approaches to sensorimotor transformations
... mathematical formalism is consistent with the responses of cortical neurons and provides a fresh perspective on the issue of frames of reference in spatial representations. The term 'sensorimotor transformation' refers to the process by which sensory stimuli are converted into motor commands. This p ...
... mathematical formalism is consistent with the responses of cortical neurons and provides a fresh perspective on the issue of frames of reference in spatial representations. The term 'sensorimotor transformation' refers to the process by which sensory stimuli are converted into motor commands. This p ...
Learning Through Imitation: a Biological Approach to Robotics
... of neurons have been termed “mirror neurons” to underlie their capacity to respond to the actions of others as if they were made by one self. Neurons with the same mirroring properties have been subsequently discovered also in the inferior parietal lobule (IPL) of the monkey, more precisely in areas ...
... of neurons have been termed “mirror neurons” to underlie their capacity to respond to the actions of others as if they were made by one self. Neurons with the same mirroring properties have been subsequently discovered also in the inferior parietal lobule (IPL) of the monkey, more precisely in areas ...
Microcircuits in visual cortex Kevan AC Martin
... orientation maps in ferret cortex in vivo: they then sliced the cortex horizontally and used photo-released glutamate to stimulate presumed monosynaptic inhibitory and excitatory inputs onto single pyramidal cells in known orientation domains in superficial and deep layers (orientation tuning is poo ...
... orientation maps in ferret cortex in vivo: they then sliced the cortex horizontally and used photo-released glutamate to stimulate presumed monosynaptic inhibitory and excitatory inputs onto single pyramidal cells in known orientation domains in superficial and deep layers (orientation tuning is poo ...
Optimal decision making theories - Bristol CS
... model shown in Figures 1b assumes that integrators mutually inhibit each other (Usher & McClelland, 2001). An analysis of the dynamics of this model reveals that, for certain parameter values, the activity of integrators is approximately proportional to the difference between the integrated evidence ...
... model shown in Figures 1b assumes that integrators mutually inhibit each other (Usher & McClelland, 2001). An analysis of the dynamics of this model reveals that, for certain parameter values, the activity of integrators is approximately proportional to the difference between the integrated evidence ...
Expectation of reward modulates cognitive signals in the basal ganglia
... considered a kind of attentional modulation. However, this is conceptually different from the type of attention investigated in previous studies. Thus, the previous studies on attention1–3 were based on the ‘attend-versus-ignore’ comparison, whereas our study was based on the ‘rewarded-versus-nonrew ...
... considered a kind of attentional modulation. However, this is conceptually different from the type of attention investigated in previous studies. Thus, the previous studies on attention1–3 were based on the ‘attend-versus-ignore’ comparison, whereas our study was based on the ‘rewarded-versus-nonrew ...
Fast Propagation of Firing Rates through Layered Networks of Noisy
... Although these coding issues have been studied extensively in single populations (Wilson and Cowan, 1972; Tsodyks and Sejnowski, 1995; van Vreeswijk and Sompolinsky, 1996; Gerstner, 1999), it is not clear how the findings generalize to the multilayer architectures relevant for cortical processing. M ...
... Although these coding issues have been studied extensively in single populations (Wilson and Cowan, 1972; Tsodyks and Sejnowski, 1995; van Vreeswijk and Sompolinsky, 1996; Gerstner, 1999), it is not clear how the findings generalize to the multilayer architectures relevant for cortical processing. M ...
Isodirectional Tuning of Adjacent Interneurons and Pyramidal Cells
... similar to lateral inhibition and refers to the suppression of the tuned response of a pyramidal neuron by inhibitory interneurons possessing orientation tuning similar but not identical to that of the pyramidal cell, a process that increases the latter’s spatial selectivity (Ringach et al. 1997). A ...
... similar to lateral inhibition and refers to the suppression of the tuned response of a pyramidal neuron by inhibitory interneurons possessing orientation tuning similar but not identical to that of the pyramidal cell, a process that increases the latter’s spatial selectivity (Ringach et al. 1997). A ...
Vision`s First Steps: Anatomy, Physiology, and Perception in the
... The functional anatomy of the retina is enormously rich and complicated. A short overview is provided here, to set a basis to understand the next few stages of the visual hierarchy. The three nuclear layers are the photoreceptor layer (which lies on the back on the retina, farthest from the light co ...
... The functional anatomy of the retina is enormously rich and complicated. A short overview is provided here, to set a basis to understand the next few stages of the visual hierarchy. The three nuclear layers are the photoreceptor layer (which lies on the back on the retina, farthest from the light co ...
Signals Conveyed in the Pulvinar Pathway from Superior Colliculus
... centered at the estimated receptive field center. The diameter of the spot stimulus was held constant and was determined by the distance between grid locations. To measure surround inhibition, the stimuli appeared at a single location, the receptive field center, but varied in size. We typically tes ...
... centered at the estimated receptive field center. The diameter of the spot stimulus was held constant and was determined by the distance between grid locations. To measure surround inhibition, the stimuli appeared at a single location, the receptive field center, but varied in size. We typically tes ...
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 ...
“Congruent” and “Opposite” Neurons: Sisters for Multisensory
... cues. In a noisy environment, however, the brain is unable to differentiate the two situations at first sight. The brain faces a “chicken vs. egg" dilemma in multisensory integration: without first integrating multiple cues to eliminate uncertainty, the brain is unable to estimate the objects reliab ...
... cues. In a noisy environment, however, the brain is unable to differentiate the two situations at first sight. The brain faces a “chicken vs. egg" dilemma in multisensory integration: without first integrating multiple cues to eliminate uncertainty, the brain is unable to estimate the objects reliab ...
invariant face and object recognition in the visual system
... generalization to similar stimuli (in the Hamming distance sense, see Rolls and Treves, 1997), graceful degradation (fault tolerance), and some locality to the representation, so that some single neurons which receive inputs from such a representation can obtain sufficient information without requir ...
... generalization to similar stimuli (in the Hamming distance sense, see Rolls and Treves, 1997), graceful degradation (fault tolerance), and some locality to the representation, so that some single neurons which receive inputs from such a representation can obtain sufficient information without requir ...
Emergence of Mirror Neurons in a Model of Gaze Following
... themselves and others. Rather, we would like to clarify how these representations may emerge, how they may be built on top of earlier and more primitive representations, and what the underlying developmental driving forces for this process may be. In order to do so, it is best to start with relative ...
... themselves and others. Rather, we would like to clarify how these representations may emerge, how they may be built on top of earlier and more primitive representations, and what the underlying developmental driving forces for this process may be. In order to do so, it is best to start with relative ...
Axonal conduction properties of antidromically identified neurons in
... of neurons outside of layer IV, particularly those in layers V and VI. One such approach for distinguishing among different local circuits in these layers may be to identify the projection target of neurons whose axon collaterals contribute to the local network. In vivo, this can be accomplished usi ...
... of neurons outside of layer IV, particularly those in layers V and VI. One such approach for distinguishing among different local circuits in these layers may be to identify the projection target of neurons whose axon collaterals contribute to the local network. In vivo, this can be accomplished usi ...
“Attention for Action” and “Response Selection” in Primate Anterior
... temporally. The Go/No-go discrimination task started once the monkeys pressed the key for ⬎0.5 sec and fixated on a small fixation square (0.5 ⫻ 0.5° in visual angle) on the CRT monitor. In the spatial discrimination task, location-related visual cues using a 0.5°-sized gray square were randomly dis ...
... temporally. The Go/No-go discrimination task started once the monkeys pressed the key for ⬎0.5 sec and fixated on a small fixation square (0.5 ⫻ 0.5° in visual angle) on the CRT monitor. In the spatial discrimination task, location-related visual cues using a 0.5°-sized gray square were randomly dis ...
Different Stimuli, Different Spatial Codes: A Visual Map and an
... Figure 4. ‘‘Point image’’ of auditory activity in comparison to visual activity as a function of target location. For each neuron, we calculated the activity for a given target location, modality, or response period as a proportion of the peak firing rate observed for any target location, modality, ...
... Figure 4. ‘‘Point image’’ of auditory activity in comparison to visual activity as a function of target location. For each neuron, we calculated the activity for a given target location, modality, or response period as a proportion of the peak firing rate observed for any target location, modality, ...
A Self-Organizing Neural Network for Contour Integration through Synchronized Firing
... Pettet, McKee, & Grzywacz, 1998; Geisler & Super, 2000) and computational models (Yen & Finkel, 1997; Li, 1998; Yen & Finkel, 1998; Geisler & Super, 2000) suggest that contour integration in the visual cortex may be due to interaction of neurons with similar orientation tuning. The models perform in ...
... Pettet, McKee, & Grzywacz, 1998; Geisler & Super, 2000) and computational models (Yen & Finkel, 1997; Li, 1998; Yen & Finkel, 1998; Geisler & Super, 2000) suggest that contour integration in the visual cortex may be due to interaction of neurons with similar orientation tuning. The models perform in ...
J. Neurophysiol. - Nonlinear Dynamics Group
... the firing activity of specific populations of neurons to animal behaviors, defining sites with neuronal activity in particular behavioral contexts as the functional areas corresponding to those behaviors. Although such observations are interesting in themselves, these studies do not necessarily exa ...
... the firing activity of specific populations of neurons to animal behaviors, defining sites with neuronal activity in particular behavioral contexts as the functional areas corresponding to those behaviors. Although such observations are interesting in themselves, these studies do not necessarily exa ...
Narrow Versus Wide Tuning Curves: What`s Best for a Population
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
A COMMON REFERENCE FRAME FOR MOVEMENT PLANS IN
... processes must be carried out. These processes include changes in the locus of attention1,2, response selection3–6, coordinate transformations7–12 and a decision to ‘act’ on the sensory stimulus13–16. Neural correlates of many of these intermediate events are reflected in activity in the posterior p ...
... processes must be carried out. These processes include changes in the locus of attention1,2, response selection3–6, coordinate transformations7–12 and a decision to ‘act’ on the sensory stimulus13–16. Neural correlates of many of these intermediate events are reflected in activity in the posterior p ...
Narrow versus wide tuning curves: What`s best for a population code?
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
Narrow versus wide tuning curves: What`s best for a population code?
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
... the same number of units in both layers, and the output layer contains lateral connections, which sharpen the tuning curves. This case is particularly relevant for neurophysiologists since this type of circuit is quite common in the cortex. In fact, some evidence suggests that a similar network is i ...
The Impact of Prior Experience With Cross-Modal
... Multisensory integration (MI) is the process by which information from multiple sensory modalities converge on single neurons. This process allows an organism to make better use of the large amount of sensory information it receives. When a rat orients toward a crossmodal light and sound stimulus, n ...
... Multisensory integration (MI) is the process by which information from multiple sensory modalities converge on single neurons. This process allows an organism to make better use of the large amount of sensory information it receives. When a rat orients toward a crossmodal light and sound stimulus, n ...
Preprint - University of Pennsylvania School of Arts and Sciences
... and indicated when they saw a target image by shifting gaze to a response dot on the screen. Our experimental design included four images presented in all possible combinations as a visual stimulus, and as an intended target, resulting in 16 experimental conditions. We held the target image fixed fo ...
... and indicated when they saw a target image by shifting gaze to a response dot on the screen. Our experimental design included four images presented in all possible combinations as a visual stimulus, and as an intended target, resulting in 16 experimental conditions. We held the target image fixed fo ...
Properties of Primary Sensory (Lemniscal) Synapses in the
... high-frequency sensory inputs through this pathway is affected by behavioral state. For instance, Poggio and Mountcastle (1963) demonstrated that the capacity for frequency following of tactile stimuli is dramatically different for thalamic cells in the waking as compared with the anesthetized monke ...
... high-frequency sensory inputs through this pathway is affected by behavioral state. For instance, Poggio and Mountcastle (1963) demonstrated that the capacity for frequency following of tactile stimuli is dramatically different for thalamic cells in the waking as compared with the anesthetized monke ...
Efficient coding hypothesis
The efficient coding hypothesis was proposed by Horace Barlow in 1961 as a theoretical model of sensory coding in the brain. Within the brain, neurons often communicate with one another by sending electrical impulses referred to as action potentials or spikes. One goal of sensory neuroscience is to decipher the meaning of these spikes in order to understand how the brain represents and processes information about the outside world. Barlow hypothesized that the spikes in the sensory system formed a neural code for efficiently representing sensory information. By efficient Barlow meant that the code minimized the number of spikes needed to transmit a given signal. This is somewhat analogous to transmitting information across the internet, where different file formats can be used to transmit a given image. Different file formats require different number of bits for representing the same image at given distortion level, and some are better suited for representing certain classes of images than others. According to this model, the brain is thought to use a code which is suited for representing visual and audio information representative of an organism's natural environment.