Transcripts/2_4 1
... 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? d. The problem here is something called the “inverse problem”. I ...
... 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? d. The problem here is something called the “inverse problem”. I ...
A Neurodynamical cortical model of visual attention and
... with different features. This process would operate for all stimulus features: colour, shape, location, etc. This process of feature selection suggests that subjects utilize top–down information (from the feature-based or object memory template) independently of stimulus location in space. The attent ...
... with different features. This process would operate for all stimulus features: colour, shape, location, etc. This process of feature selection suggests that subjects utilize top–down information (from the feature-based or object memory template) independently of stimulus location in space. The attent ...
Genardi Brodmann-Detail
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
Brodmann-Detail
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
directory of functions - Stress Therapy Solutions
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
... Traditionally BA8 has been regarded as the “frontal eye field”. However, functional studies report the participation of BA8 in a wide diversity of functions, including: motor, language, executive functions, memory, and attention. Only two studies refer to its participation in eye movements (horizont ...
The Receptive Fields of Inferior Temporal Cortex Neurons in Natural
... anterior inferior temporal cortex neurons (at coordinates that were typically 3–7 mm posterior to the sphenoid reference; see Fig. 7) did not respond to the background image (which for most experiments was that shown in Fig. 1), but if the neuron did respond, other background images were tried. (In ...
... anterior inferior temporal cortex neurons (at coordinates that were typically 3–7 mm posterior to the sphenoid reference; see Fig. 7) did not respond to the background image (which for most experiments was that shown in Fig. 1), but if the neuron did respond, other background images were tried. (In ...
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 ...
Neural processes underlying conscious perception
... non-conscious stimuli, and higher areas, in the parietal, frontal and cingulate cortex, that appear to be specifically involved in conscious perception. Some studies also highlight the fact that, contrary to sensory areas, these fronto-parietal sites seem to be involved in conscious perception regard ...
... non-conscious stimuli, and higher areas, in the parietal, frontal and cingulate cortex, that appear to be specifically involved in conscious perception. Some studies also highlight the fact that, contrary to sensory areas, these fronto-parietal sites seem to be involved in conscious perception regard ...
pdf file. - Harvard Vision Lab
... Because the SC–MD–FEF pathway on each side of the brain represents only contraversive saccades10, a further prediction was that our unilateral inactivations would eliminate corollary discharge for contraversive saccades only. Therefore shifts accompanying contraversive saccades, but not ipsiversive ...
... Because the SC–MD–FEF pathway on each side of the brain represents only contraversive saccades10, a further prediction was that our unilateral inactivations would eliminate corollary discharge for contraversive saccades only. Therefore shifts accompanying contraversive saccades, but not ipsiversive ...
PDF preprint - The Computational Neurobiology Laboratory
... pressure on the eyeballs (Tyler, 1978), in “near death” experiences (Blackmore, 1992), and most strikingly, shortly after taking hallucinogens containing ingredients such as LSD, cannabis, mescaline, or psilocybin (Siegel & Jarvik, 1975). The images do not move with the eyes and sometimes are fixed i ...
... pressure on the eyeballs (Tyler, 1978), in “near death” experiences (Blackmore, 1992), and most strikingly, shortly after taking hallucinogens containing ingredients such as LSD, cannabis, mescaline, or psilocybin (Siegel & Jarvik, 1975). The images do not move with the eyes and sometimes are fixed i ...
View PDF - Laboratory of Brain, Hearing and Behavior
... Selection deficits caused by SC inactivation in monkeys and improved peak discrimination by switch-like responses in the OT of owls. (a) Effect of focal SC inactivation on behavioral performance by monkeys in a contrast, oddball task. The task was the same as described in Figure 2a, except that the ...
... Selection deficits caused by SC inactivation in monkeys and improved peak discrimination by switch-like responses in the OT of owls. (a) Effect of focal SC inactivation on behavioral performance by monkeys in a contrast, oddball task. The task was the same as described in Figure 2a, except that the ...
Contextual modulation of primary visual cortex by auditory signals
... Time-resolved multisensory interactions can be studied using electrophysiological techniques that reveal early effects in sensory cortices. For example, audiosomatosensory interactions are seen in the central/postcentral scalp at approximately 50 ms after the stimulus presentation, consistent with m ...
... Time-resolved multisensory interactions can be studied using electrophysiological techniques that reveal early effects in sensory cortices. For example, audiosomatosensory interactions are seen in the central/postcentral scalp at approximately 50 ms after the stimulus presentation, consistent with m ...
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 ...
WHEN THE visual cortex in the occipital lobe is electrically
... remained unaffected. No epileptiform activity was experienced by the other two subjects during our experiments. The second and third patients reported phosphenes that were punctate (probably less than 0.2" of visual arc) and essentially colourless ('white' or 'yellowish'). In both, most of the one h ...
... remained unaffected. No epileptiform activity was experienced by the other two subjects during our experiments. The second and third patients reported phosphenes that were punctate (probably less than 0.2" of visual arc) and essentially colourless ('white' or 'yellowish'). In both, most of the one h ...
A Feedback Model of Visual Attention
... The Reynolds and Desimone model, in common with others (e.g., Olshausen et al., 1993), uses top-down signals to multiplicatively modulate the synaptic strengths of inter-regional connections so that attended information can be selectively routed to higher cortical regions. Equivalent results can be ...
... The Reynolds and Desimone model, in common with others (e.g., Olshausen et al., 1993), uses top-down signals to multiplicatively modulate the synaptic strengths of inter-regional connections so that attended information can be selectively routed to higher cortical regions. Equivalent results can be ...
PDF hosted at the Radboud Repository of the Radboud University Nijmegen
... for a coherent representation of the respective objects. As already shown by the studies of the Gestalt psychologists, this process of feature binding follows certain “Gestalt criteria” that include, for instance, the proximity or similarity of features (Köhler, 1930). This binding problem, as chara ...
... for a coherent representation of the respective objects. As already shown by the studies of the Gestalt psychologists, this process of feature binding follows certain “Gestalt criteria” that include, for instance, the proximity or similarity of features (Köhler, 1930). This binding problem, as chara ...
Large-Field Visual Motion Directly Induces an Involuntary Rapid
... Recent neuroscience studies have been concerned with how aimed movements are generated on the basis of target localization. However, visual information from the surroundings as well as from the target can influence arm motor control, in a manner similar to known effects in postural and ocular motor ...
... Recent neuroscience studies have been concerned with how aimed movements are generated on the basis of target localization. However, visual information from the surroundings as well as from the target can influence arm motor control, in a manner similar to known effects in postural and ocular motor ...
Implications on visual apperception: energy, duration
... perception/representation/function) requires energetic conditions. The brain can perceive, detect, discriminate, and recognize consciously just those pieces of external information, which reach a critical intrinsic energetic level (guaranteed by neuronal mitochondrial activity), an adequate duration ...
... perception/representation/function) requires energetic conditions. The brain can perceive, detect, discriminate, and recognize consciously just those pieces of external information, which reach a critical intrinsic energetic level (guaranteed by neuronal mitochondrial activity), an adequate duration ...
31 - UCL
... visuotopic organization (e.g., mirror-image or non-mirror-image map of hemifield, bounding areas, pattern of map discontinuities, degree of retinotopy), and physiological properties (e.g., excitatory receptive field size, direction selectivity, attention-related modulation). Areas differ in the degr ...
... visuotopic organization (e.g., mirror-image or non-mirror-image map of hemifield, bounding areas, pattern of map discontinuities, degree of retinotopy), and physiological properties (e.g., excitatory receptive field size, direction selectivity, attention-related modulation). Areas differ in the degr ...
Hemispheric Asymmetry in Visual Perception Arises from Differential Encoding
... variances are chosen as the two extreme cases of denseness/sparseness of the connections in order to examine the qualitative differences between them. The connections from the hidden layer to the output layer are completely symmetric to those from the input layer to the hidden layer. After obtaining ...
... variances are chosen as the two extreme cases of denseness/sparseness of the connections in order to examine the qualitative differences between them. The connections from the hidden layer to the output layer are completely symmetric to those from the input layer to the hidden layer. After obtaining ...
ATTENTIONAL MODULATION OF VISUAL PROCESSING John H
... A replication of this observation is illustrated in Figure 2, which shows data gathered by Chelazzi et al. (2001). Each line in Panel B shows the response averaged across a population of 76 neurons recorded in area V4 of monkeys performing a visual search task. As illustrated in Panel A on each tria ...
... A replication of this observation is illustrated in Figure 2, which shows data gathered by Chelazzi et al. (2001). Each line in Panel B shows the response averaged across a population of 76 neurons recorded in area V4 of monkeys performing a visual search task. As illustrated in Panel A on each tria ...
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 ...
Seeing faces and objects with the “mind`s eye”
... parietal and frontal areas. Finally, we examined whether the DCM analysis would reveal different patterns of effective connectivity during imagery of faces, houses and chairs in parietal and frontal cortices, as our original SPM analysis did not show category-specific imagery activation within these ...
... parietal and frontal areas. Finally, we examined whether the DCM analysis would reveal different patterns of effective connectivity during imagery of faces, houses and chairs in parietal and frontal cortices, as our original SPM analysis did not show category-specific imagery activation within these ...
“Black” Responses Dominate Macaque Primary Visual Cortex
... grid) dark and bright squares (0.2 ° ⫻ 0.2 °) against a gray background (luminance, 59 cd/m 2). The luminance of bright and dark squares was adjusted so the contrasts from the light increment (luminance, 107 cd/ m 2) and light decrement (luminance, 11 cd/m 2) were equal. The stimulus was sparse in b ...
... grid) dark and bright squares (0.2 ° ⫻ 0.2 °) against a gray background (luminance, 59 cd/m 2). The luminance of bright and dark squares was adjusted so the contrasts from the light increment (luminance, 107 cd/ m 2) and light decrement (luminance, 11 cd/m 2) were equal. The stimulus was sparse in b ...
contextual influences on visual processing
... surely not the only means by which perceptual context effects are implemented neuronally. For example, because surround modulation takes on a very specific spatial form (by definition), it is difficult to imagine how it might account for perceptual effects that occur when contextual information is s ...
... surely not the only means by which perceptual context effects are implemented neuronally. For example, because surround modulation takes on a very specific spatial form (by definition), it is difficult to imagine how it might account for perceptual effects that occur when contextual information is s ...
Visual N1
The visual N1 is a visual evoked potential, a type of event-related electrical potential (ERP), that is produced in the brain and recorded on the scalp. The N1 is so named to reflect the polarity and typical timing of the component. The ""N"" indicates that the polarity of the component is negative with respect to an average mastoid reference. The ""1"" originally indicated that it was the first negative-going component, but it now better indexes the typical peak of this component, which is around 150 to 200 milliseconds post-stimulus. The N1 deflection may be detected at most recording sites, including the occipital, parietal, central, and frontal electrode sites. Although, the visual N1 is widely distributed over the entire scalp, it peaks earlier over frontal than posterior regions of the scalp, suggestive of distinct neural and/or cognitive correlates. The N1 is elicited by visual stimuli, and is part of the visual evoked potential – a series of voltage deflections observed in response to visual onsets, offsets, and changes. Both the right and left hemispheres generate an N1, but the laterality of the N1 depends on whether a stimulus is presented centrally, laterally, or bilaterally. When a stimulus is presented centrally, the N1 is bilateral. When presented laterally, the N1 is larger, earlier, and contralateral to the visual field of the stimulus. When two visual stimuli are presented, one in each visual field, the N1 is bilateral. In the latter case, the N1’s asymmetrical skewedness is modulated by attention. Additionally, its amplitude is influenced by selective attention, and thus it has been used to study a variety of attentional processes.