Visual Response Properties of Neurons in Four Extrastriate Visual
... to a light- or dark-bar stimulus, the effect of varying the orientation and direction of a moving bar was studied first. The responses were displayed as they occurred on an oscilloscope as peristimulus time histograms. As soon as the five runs of the stimulus sequence were completed, the orientation ...
... to a light- or dark-bar stimulus, the effect of varying the orientation and direction of a moving bar was studied first. The responses were displayed as they occurred on an oscilloscope as peristimulus time histograms. As soon as the five runs of the stimulus sequence were completed, the orientation ...
attention - CMU Graphics
... ● Changes strength of neurons’ response without changing underlying response properties ● Enhances synchronization of neuronal activity ● Spatial attention will increase the gain of all neurons whose receptive field overlaps the current attentional focus, creating an enhanced representation at that ...
... ● Changes strength of neurons’ response without changing underlying response properties ● Enhances synchronization of neuronal activity ● Spatial attention will increase the gain of all neurons whose receptive field overlaps the current attentional focus, creating an enhanced representation at that ...
Words and pictures in the left fusiform gyrus
... to objects from the same category, which makes elaborate shape processing essential to perform this task (Gerlach et al., 2004, 2005). In addition to PET-measurements, we also recorded reaction times (RTs) in all tasks. Our general expectation was that demands on shape processing would influence rCB ...
... to objects from the same category, which makes elaborate shape processing essential to perform this task (Gerlach et al., 2004, 2005). In addition to PET-measurements, we also recorded reaction times (RTs) in all tasks. Our general expectation was that demands on shape processing would influence rCB ...
Location of the polysensory zone in the precentral gyrus
... receptive field. Objects farther than about 20 cm from the body did not give consistent responses. One site had a visual response but no detectable somatosensory response. The visual response at this location was similar to the responses found at the other locations, in that it was best for objects ...
... receptive field. Objects farther than about 20 cm from the body did not give consistent responses. One site had a visual response but no detectable somatosensory response. The visual response at this location was similar to the responses found at the other locations, in that it was best for objects ...
Spatial Responsiveness of Monkey Hippocampal Neurons to
... activity of neurons in the hippocampal formation of the conscious monkey was recorded during presentation of various visual and auditory stimuli from several directions around the monkey. Of 1,047 neurons recorded, 106 (10.1%) responded to some stimuli from one or more directions. Of these 106 neuro ...
... activity of neurons in the hippocampal formation of the conscious monkey was recorded during presentation of various visual and auditory stimuli from several directions around the monkey. Of 1,047 neurons recorded, 106 (10.1%) responded to some stimuli from one or more directions. Of these 106 neuro ...
Hemispheric Differences in the Activation of
... hemispheric differences when the perceptual form of objects was altered on repeated presentation using a visual half-field technique in combination with a repetition priming procedure (Marsolek, 1995, 1999). In one study (Marsolek, 1999), participants viewed objects presented centrally in a study ph ...
... hemispheric differences when the perceptual form of objects was altered on repeated presentation using a visual half-field technique in combination with a repetition priming procedure (Marsolek, 1995, 1999). In one study (Marsolek, 1999), participants viewed objects presented centrally in a study ph ...
neural mechanisms for detecting and remembering novel events
... LEARNING, reflecting many weeks of training. Familiaritydependent reductions in neural activity have also been revealed in early visual areas by two perceptual learning studies26,27. Monkeys were trained on a task that involved repeated presentation (and discrimination) of gratings of a particular o ...
... LEARNING, reflecting many weeks of training. Familiaritydependent reductions in neural activity have also been revealed in early visual areas by two perceptual learning studies26,27. Monkeys were trained on a task that involved repeated presentation (and discrimination) of gratings of a particular o ...
The Emergence of Selective Attention through - laral
... results of these experiments indicate that representations of relevant objects are enhanced with respect to non-relevant information in terms of visually driven responses, at level of both individual neural responses and coherent firing within the critical neuronal population [7]. Other than enhanci ...
... results of these experiments indicate that representations of relevant objects are enhanced with respect to non-relevant information in terms of visually driven responses, at level of both individual neural responses and coherent firing within the critical neuronal population [7]. Other than enhanci ...
Evidence of Basal Temporo-occipital Cortex
... activation to ‘front’ compared to ‘back’ objects. This discrepancy may be due to the spatial resolution of the subdural technique. Our electrodes had 1 mm diameter exposure separated by 10 mm and therefore they had a restricted area or recording which may have included only fusiform regions with mor ...
... activation to ‘front’ compared to ‘back’ objects. This discrepancy may be due to the spatial resolution of the subdural technique. Our electrodes had 1 mm diameter exposure separated by 10 mm and therefore they had a restricted area or recording which may have included only fusiform regions with mor ...
The effect of learning on the face selective responses of neurons in
... large as to the optimal non-face stimulus, and that this difference should be significant. (In fact, the majority of the neurons in the cortex in the superior temporal suleus classified as showing responses selective for faces responded much more specifically than this. Further information on and di ...
... large as to the optimal non-face stimulus, and that this difference should be significant. (In fact, the majority of the neurons in the cortex in the superior temporal suleus classified as showing responses selective for faces responded much more specifically than this. Further information on and di ...
Perceptual Expectation Evokes Category
... of the recognition process has been studied is with ambiguous images that gradually become disambiguated over several seconds. In the 1960s, Bruner and Potter (1964) found that when gradually reducing the blurriness of an image, the blurrier the image was when the sequence began, the longer it took ...
... of the recognition process has been studied is with ambiguous images that gradually become disambiguated over several seconds. In the 1960s, Bruner and Potter (1964) found that when gradually reducing the blurriness of an image, the blurrier the image was when the sequence began, the longer it took ...
the clinical role of evoked potentials
... (SSEPs), and brainstem auditory evoked potentials (BSAEPs) are tested most frequently. Longer latency responses that are related to higher ‘‘cognitive’’ functions such as event related potentials (ERPs), contingent negative variant (CNV), and sensory potentials after stimulation with CO2 lasers are ...
... (SSEPs), and brainstem auditory evoked potentials (BSAEPs) are tested most frequently. Longer latency responses that are related to higher ‘‘cognitive’’ functions such as event related potentials (ERPs), contingent negative variant (CNV), and sensory potentials after stimulation with CO2 lasers are ...
Primary Visual Pathway
... • Each eye sees a part of the visual space that defines its visual field ...
... • Each eye sees a part of the visual space that defines its visual field ...
reviews - Center for Complex Systems and Brain Sciences
... detectors that respond best to those features that are present at the locations visited by observers while freeviewing images50,51. For instance, Zetzsche et al.50,52 showed using an eye-tracking device how the eyes preferentially fixate regions with multiple superimposed orientations such as corner ...
... detectors that respond best to those features that are present at the locations visited by observers while freeviewing images50,51. For instance, Zetzsche et al.50,52 showed using an eye-tracking device how the eyes preferentially fixate regions with multiple superimposed orientations such as corner ...
Implications on visual apperception: energy, duration
... equilibrium (Qian and Beard, 2005) that make possible to pick up extreme weak different information from the outside world. The sensory systems, which are results of nonlinear biochemical processes of cells, have extreme sensitivity to pick up diverse information from the external world. Blindsight ...
... equilibrium (Qian and Beard, 2005) that make possible to pick up extreme weak different information from the outside world. The sensory systems, which are results of nonlinear biochemical processes of cells, have extreme sensitivity to pick up diverse information from the external world. Blindsight ...
Visual areas and spatial summation in human visual cortex
... (fovea to 20 deg; see inset) that is commonly used (Wandell, 1999). The data in this figure represent the average of five separate scans. To emphasize the dorsal activation, the overlay is shown only for measurements that are located near the transverse occipital sulcus (TOS) and correlated with the ...
... (fovea to 20 deg; see inset) that is commonly used (Wandell, 1999). The data in this figure represent the average of five separate scans. To emphasize the dorsal activation, the overlay is shown only for measurements that are located near the transverse occipital sulcus (TOS) and correlated with the ...
The Constructive Nature of Visual Processing
... and global contours, and distinguishing foreground from background (see Chapter 27). The highest level involves object recognition (see Chapter 28). Once a scene has been parsed by the brain and objects recognized, the objects can be matched with memories of shapes and their associated meanings. Vis ...
... and global contours, and distinguishing foreground from background (see Chapter 27). The highest level involves object recognition (see Chapter 28). Once a scene has been parsed by the brain and objects recognized, the objects can be matched with memories of shapes and their associated meanings. Vis ...
Visual speech circuits in profound acquired
... It is commonly held that losing one sense provokes cross-modal takeover of deprived cortical areas, and therefore results in a benefit for the remaining modalities. Using functional magnetic resonance imaging (fMRI), we assessed the impact of acquired deafness on the brain network related to speechr ...
... It is commonly held that losing one sense provokes cross-modal takeover of deprived cortical areas, and therefore results in a benefit for the remaining modalities. Using functional magnetic resonance imaging (fMRI), we assessed the impact of acquired deafness on the brain network related to speechr ...
A multi-level account of selective attention
... The modulation of neural responses by spatially selective attention was originally demonstrated in the extrastriate cortex. In a seminal study, Moran and Desimone (Moran and Desimone 1985) recorded the activity of neurons in area V4 from monkeys trained to direct attention to a spatial location with ...
... The modulation of neural responses by spatially selective attention was originally demonstrated in the extrastriate cortex. In a seminal study, Moran and Desimone (Moran and Desimone 1985) recorded the activity of neurons in area V4 from monkeys trained to direct attention to a spatial location with ...
Structural brain MRI studies in eye diseases: are they clinically
... Because of the well-defined retinotopic organization of the connections of the visual pathways, this may affect specific parts of the visual pathways and cortex, as a result of either deprivation or transsynaptic degeneration. For this reason, over the past several years, numerous structural magnetic r ...
... Because of the well-defined retinotopic organization of the connections of the visual pathways, this may affect specific parts of the visual pathways and cortex, as a result of either deprivation or transsynaptic degeneration. For this reason, over the past several years, numerous structural magnetic r ...
Superior Colliculus and Visual Spatial Attention
... both the stimulus-driven and top-down factors that regulate spatial attention and saccade selection (Fecteau & Munoz 2006). Although SC activity may have been restricted to spatial attention associated with eye movements, other studies have shown that the SC may play a role in covert attention. In o ...
... both the stimulus-driven and top-down factors that regulate spatial attention and saccade selection (Fecteau & Munoz 2006). Although SC activity may have been restricted to spatial attention associated with eye movements, other studies have shown that the SC may play a role in covert attention. In o ...
Visual signals in the dorsolateral pontine nucleus of the alert
... spot, the velocity of visual stimulus movement approximated retinal image or "slip" velocity. When the small, 0.6 deg diameter test spot was oscillated with different amplitudes at 0.2 Hz, the magnitude of the transient response generally increased with increases in peak stimulus velocity (Fig. 1D). ...
... spot, the velocity of visual stimulus movement approximated retinal image or "slip" velocity. When the small, 0.6 deg diameter test spot was oscillated with different amplitudes at 0.2 Hz, the magnitude of the transient response generally increased with increases in peak stimulus velocity (Fig. 1D). ...
31 - UCL
... These maps (and data from other species) suggest that the parcellation of most of the cortex has not changed radically during the evolution of the primate order. Notably, there does not seem to be any significant increase in regions where modalities overlap; rather, modality-specific areas have inc ...
... These maps (and data from other species) suggest that the parcellation of most of the cortex has not changed radically during the evolution of the primate order. Notably, there does not seem to be any significant increase in regions where modalities overlap; rather, modality-specific areas have inc ...
Functional Recovery of the Injured Optic Chiasma after Omental
... previously. The surgical findings were as follows: 1) multiple adhesions between the dura mater and right temporallobe; 2) infarct and cyst in the temporal pole; 3) hypotrophy of the chiasma and both optic nerves (left optic nerve reduced to 80% and right optic nerve to 50%); 4) marked pallor of the ...
... previously. The surgical findings were as follows: 1) multiple adhesions between the dura mater and right temporallobe; 2) infarct and cyst in the temporal pole; 3) hypotrophy of the chiasma and both optic nerves (left optic nerve reduced to 80% and right optic nerve to 50%); 4) marked pallor of the ...
Visual extinction
Visual extinction is a neurological disorder which occurs following damage to the parietal lobe of the brain. It is similar to, but distinct from, hemispatial neglect. Visual extinction has the characteristic symptom of difficulty to perceive contralesional stimuli when presented simultaneously with an ipsilesional stimulus, but the ability to correctly identify them when not presented simultaneously. Under simultaneous presentation, the contralesional stimulus is apparently ignored by the patient, or extinguished. This deficiency may lead to difficulty on behalf of the patient with processing the stimuli’s 3D position.