Predictive Coding as a Model of Biased Competition in Visual
... WSi+1 ySi+1 is the top-down prediction from the next highest stage, WSi = [w1Si , . . . , wnSi ]T is an n by m matrix of synaptic weight values, each row of which contains the feedforward weights received by a single node, and ζ, η, and ϑ are constant scale factors. Note that in certain simulations ...
... WSi+1 ySi+1 is the top-down prediction from the next highest stage, WSi = [w1Si , . . . , wnSi ]T is an n by m matrix of synaptic weight values, each row of which contains the feedforward weights received by a single node, and ζ, η, and ϑ are constant scale factors. Note that in certain simulations ...
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... making a saccadic eye movement to the location of the target within 600 ms. Generally, ‘miss’ trials occurred when the monkey failed to make a saccade at all (61% of miss trials) since the timing of target onset was variable and the target itself was difficult to detect; however, miss trials also in ...
... making a saccadic eye movement to the location of the target within 600 ms. Generally, ‘miss’ trials occurred when the monkey failed to make a saccade at all (61% of miss trials) since the timing of target onset was variable and the target itself was difficult to detect; however, miss trials also in ...
Schwartz
... have anatomic correlates found in the arborization of thalamocortical afferents, as well as the interconnectedness of isoorientation domains via long-range horizontal excitatory connections (Mountcastle, 1957, 1982; Hubel and Wiesel, 1962, 1963; Gilbert and Wiesel, 1989; Malach et al., 1993; Weliky ...
... have anatomic correlates found in the arborization of thalamocortical afferents, as well as the interconnectedness of isoorientation domains via long-range horizontal excitatory connections (Mountcastle, 1957, 1982; Hubel and Wiesel, 1962, 1963; Gilbert and Wiesel, 1989; Malach et al., 1993; Weliky ...
Neural Correlates of Perceived Brightness in the Retina, Lateral
... with an intravenous inf usion of atracurium besylate (initial dose 5 mg, 0.6 –1.2 mg z kg 21 z hr 21) and artificially respired. The stroke rate and volume of the respirator were adjusted to maintain an end-tidal C O2 between 3.5 and 4.0%. Rectal temperature was maintained near 38°C with a heating p ...
... with an intravenous inf usion of atracurium besylate (initial dose 5 mg, 0.6 –1.2 mg z kg 21 z hr 21) and artificially respired. The stroke rate and volume of the respirator were adjusted to maintain an end-tidal C O2 between 3.5 and 4.0%. Rectal temperature was maintained near 38°C with a heating p ...
Response characteristics of neurons in the pulvinar of awake cats to
... onset. If responses to at least 25 stimulus sweeps or saccades had been collected, a t-test was used to determine significance; for less than 25 sweeps a Mann-Whitney rank sum test was used. Responses were characterized by the latency to half of the peak activity, response duration, and average acti ...
... onset. If responses to at least 25 stimulus sweeps or saccades had been collected, a t-test was used to determine significance; for less than 25 sweeps a Mann-Whitney rank sum test was used. Responses were characterized by the latency to half of the peak activity, response duration, and average acti ...
Modulation of Inhibition of Return by the Dopamine D2 Receptor
... display contained 12 Gabor patches (100% contrast, spatial frequency: 3 cycles/degree of visual angle; space constant: 1 degree of visual angle), 3 within each frame. The target (always the central of the 3 Gabor patches) was tilted ±45" away from vertical, and all other patches were vertically orie ...
... display contained 12 Gabor patches (100% contrast, spatial frequency: 3 cycles/degree of visual angle; space constant: 1 degree of visual angle), 3 within each frame. The target (always the central of the 3 Gabor patches) was tilted ±45" away from vertical, and all other patches were vertically orie ...
State dependent activity in monkey visual cortex
... rhesus monkey can be greatly modulated depending on the behavioral significance of a visual stimulus. These findings suggest that signals arising from sources other than the retina may represent an important aspect of neuronal activity in visual cortex. Understanding the extent and nature of these e ...
... rhesus monkey can be greatly modulated depending on the behavioral significance of a visual stimulus. These findings suggest that signals arising from sources other than the retina may represent an important aspect of neuronal activity in visual cortex. Understanding the extent and nature of these e ...
The Optic Tectum of Birds - Department of Psychology
... Figure 3. Connectivity of the isthmal nuclei with the tectum. (A) shows a coronal section through the tectum showing typical injections of fluorescent biotinylated dextran amines (BDA). A retrogradely labelled cell and anterogradely labelled terminals from the red injection can be seen in parvocellu ...
... Figure 3. Connectivity of the isthmal nuclei with the tectum. (A) shows a coronal section through the tectum showing typical injections of fluorescent biotinylated dextran amines (BDA). A retrogradely labelled cell and anterogradely labelled terminals from the red injection can be seen in parvocellu ...
Visual Processing in the Primate Brain
... evolved biological system, the goal of vision is not to produce a veridical description of the external world but a description that facilitates adaptive behavior. Those aspects of the input that contain information critical for behavior will be emphasized and those aspects that carry little informa ...
... evolved biological system, the goal of vision is not to produce a veridical description of the external world but a description that facilitates adaptive behavior. Those aspects of the input that contain information critical for behavior will be emphasized and those aspects that carry little informa ...
Selective amplification of the S
... (InFocus LP250, resolution 1024 · 768, frame rate = 80 Hz, mean luminance = 30 cdm)2). The screen was placed 2.7 m from the subject. For the psychophysical experiments used to determine detection threshold and isoluminance, stimuli were generated using a VSG 2 ⁄ 5 graphics board with 15 bits contras ...
... (InFocus LP250, resolution 1024 · 768, frame rate = 80 Hz, mean luminance = 30 cdm)2). The screen was placed 2.7 m from the subject. For the psychophysical experiments used to determine detection threshold and isoluminance, stimuli were generated using a VSG 2 ⁄ 5 graphics board with 15 bits contras ...
Color responses of the human lateral geniculate nucleus: selective
... (InFocus LP250, resolution 1024 · 768, frame rate = 80 Hz, mean luminance = 30 cdm)2). The screen was placed 2.7 m from the subject. For the psychophysical experiments used to determine detection threshold and isoluminance, stimuli were generated using a VSG 2 ⁄ 5 graphics board with 15 bits contras ...
... (InFocus LP250, resolution 1024 · 768, frame rate = 80 Hz, mean luminance = 30 cdm)2). The screen was placed 2.7 m from the subject. For the psychophysical experiments used to determine detection threshold and isoluminance, stimuli were generated using a VSG 2 ⁄ 5 graphics board with 15 bits contras ...
Response Suppression in V1 Agrees with Psychophysics of
... to the occipital pole. The slices covered most of the occipital lobe. Each scanning session began by acquiring a set of anatomical images using a T1-weighted SPGR pulse sequence in the same slices as the functional images (FOV, 220 mm; TR, 68 msec; TE, 15 msec; echo train length, 2). These inplane a ...
... to the occipital pole. The slices covered most of the occipital lobe. Each scanning session began by acquiring a set of anatomical images using a T1-weighted SPGR pulse sequence in the same slices as the functional images (FOV, 220 mm; TR, 68 msec; TE, 15 msec; echo train length, 2). These inplane a ...
Author`s personal copy
... sheet, thus representing the visual field in a continuous fashion [23]. This locally continuous representation may be interrupted, for example, when only the contralateral half or upper/lower portion of the visual field is mapped (common in early visual and somatotopic areas). A complete representat ...
... sheet, thus representing the visual field in a continuous fashion [23]. This locally continuous representation may be interrupted, for example, when only the contralateral half or upper/lower portion of the visual field is mapped (common in early visual and somatotopic areas). A complete representat ...
The Influence of Target Properties and the Possible
... from the fovea. This function is actually U-shaped, meaning that the shortest latencies would be for targets within about 2° and 10° from the fovea and relatively longer ones within 1° and 2° (Liversedge, Gilchrist, & Everling, 2011). Target location probabilities (Liu et al., 2010) and attentional ...
... from the fovea. This function is actually U-shaped, meaning that the shortest latencies would be for targets within about 2° and 10° from the fovea and relatively longer ones within 1° and 2° (Liversedge, Gilchrist, & Everling, 2011). Target location probabilities (Liu et al., 2010) and attentional ...
How Do We See the World?
... Dogs provide a good example of the difference between the world that is “out there” and our perception of it. Dogs have very limited capacity to distinguish colors; they likely see very little color. Yet dogs have an olfactory system that smells in “Technicolor” compared with our simple “black and w ...
... Dogs provide a good example of the difference between the world that is “out there” and our perception of it. Dogs have very limited capacity to distinguish colors; they likely see very little color. Yet dogs have an olfactory system that smells in “Technicolor” compared with our simple “black and w ...
Rhythms for Cognition: Communication through
... communication. Bidirectional communication is implemented separately for the two directions, via unidirectional entrainment per direction. Anatomical data actually show that for each direction of communication, the communicating brain areas have specialized neuronal groups, i.e. a given brain area h ...
... communication. Bidirectional communication is implemented separately for the two directions, via unidirectional entrainment per direction. Anatomical data actually show that for each direction of communication, the communicating brain areas have specialized neuronal groups, i.e. a given brain area h ...
fMR-adaptation reveals separate processing regions for the
... participants attended to the surface properties of the same objects, activation was present in more medial and anterior regions in the collateral sulcus (CoS) and the inferior occipital gyrus (IOG). We went on to demonstrate that attending explicitly to texture activated regions in the IOG and the C ...
... participants attended to the surface properties of the same objects, activation was present in more medial and anterior regions in the collateral sulcus (CoS) and the inferior occipital gyrus (IOG). We went on to demonstrate that attending explicitly to texture activated regions in the IOG and the C ...
Activity of Neurons in Anterior Inferior Temporal Cortex during a
... tasks that require the monkey to retain memories across a “blank” retention interval, during which no visual stimuli are presented. Outside the laboratory, however, memories frequently must be retained while new information is being processed. It is not understood how IT neurons can participate in m ...
... tasks that require the monkey to retain memories across a “blank” retention interval, during which no visual stimuli are presented. Outside the laboratory, however, memories frequently must be retained while new information is being processed. It is not understood how IT neurons can participate in m ...
The Representation of Complex Images in Spatial Frequency
... The organization of cat primary visual cortex has been well mapped using simple stimuli such as sinusoidal gratings, revealing superimposed maps of orientation and spatial frequency preferences. However, it is not yet understood how complex images are represented across these maps. In this study, we ...
... The organization of cat primary visual cortex has been well mapped using simple stimuli such as sinusoidal gratings, revealing superimposed maps of orientation and spatial frequency preferences. However, it is not yet understood how complex images are represented across these maps. In this study, we ...
Models of Attentional Learning - Indiana University Bloomington
... suppressing attention to other cues or dimensions, then it is natural to suppose that the learned attention should perseverate into subsequent training even if the dimension values and/or the category assignments change. In particular, if the same dimension remains relevant after the change, then re ...
... suppressing attention to other cues or dimensions, then it is natural to suppose that the learned attention should perseverate into subsequent training even if the dimension values and/or the category assignments change. In particular, if the same dimension remains relevant after the change, then re ...
Retinotopic Organization and Functional Subdivisions of the Human
... sorted into these bins based on the phase of their responses. The bins centered on the top and bottom vertical meridians contained voxels from both the left and right LGN. The volumes of voxels within each sector were totaled and averaged across subjects, and the mean polar angle representation was ...
... sorted into these bins based on the phase of their responses. The bins centered on the top and bottom vertical meridians contained voxels from both the left and right LGN. The volumes of voxels within each sector were totaled and averaged across subjects, and the mean polar angle representation was ...
Chapter 4 monkey
... which of the two targets was to be selected for an eye movement (Kim and Shadlen 1999; Roitman and Shadlen 2002). These studies investigated saccade target selection (decisions) in the presence of stochastic and unreliable sensory evidence. In these situations the optimal strategy is to integrate se ...
... which of the two targets was to be selected for an eye movement (Kim and Shadlen 1999; Roitman and Shadlen 2002). These studies investigated saccade target selection (decisions) in the presence of stochastic and unreliable sensory evidence. In these situations the optimal strategy is to integrate se ...
invariant face and object recognition in the visual system
... objects. Thus, they showed ensemble, sparse-distributed, encoding. The information available about which object was seen increased approximately linearly with the number of neurons in the ensemble. These experiments provide preliminary evidence that there is a view-invariant representation of object ...
... objects. Thus, they showed ensemble, sparse-distributed, encoding. The information available about which object was seen increased approximately linearly with the number of neurons in the ensemble. These experiments provide preliminary evidence that there is a view-invariant representation of object ...
The neural mechanisms of perceptual filling-in
... bar was superimposed on an ellipse, and measured the spread of attention between the bar and ellipse. They manipulated the depth order of the bar and the ellipse by changing the binocular disparity of the stimulus. In one situation, the ellipse was perceived to be in front of the bar, and the ellips ...
... bar was superimposed on an ellipse, and measured the spread of attention between the bar and ellipse. They manipulated the depth order of the bar and the ellipse by changing the binocular disparity of the stimulus. In one situation, the ellipse was perceived to be in front of the bar, and the ellips ...
Representation of the Visual Field in the Human Occipital Cortex
... Field Analyzer (Allergan-Humphrey Instruments, San Leandro, Calif). Patients with incomplete homonymous hemianopia were included in the study. The central 30-2 program only tests the retinal threshold at 76 predetermined points within the central 30° of vision, with 19 points tested in each quadrant ...
... Field Analyzer (Allergan-Humphrey Instruments, San Leandro, Calif). Patients with incomplete homonymous hemianopia were included in the study. The central 30-2 program only tests the retinal threshold at 76 predetermined points within the central 30° of vision, with 19 points tested in each quadrant ...
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.