The role of neuronal synchronization in selective attention
... change had occurred. This finding suggests that the processing or the signalling of a sensory change is more efficient when it is handled by an area that is engaged in enhanced gamma-band synchronization [6]. Importantly, the influence of local synchronization of behavioural responses was spatiall ...
... change had occurred. This finding suggests that the processing or the signalling of a sensory change is more efficient when it is handled by an area that is engaged in enhanced gamma-band synchronization [6]. Importantly, the influence of local synchronization of behavioural responses was spatiall ...
Saccadic Eye Movements Modulate Visual Responses in the Lateral
... visual structures respond as they do during constant fixation, the resulting barrage of action potentials could disrupt the information that enters the brain soon after each eye movement. Many mammals make fast eye movements, but saccades reach higher velocities and are more frequent in primates tha ...
... visual structures respond as they do during constant fixation, the resulting barrage of action potentials could disrupt the information that enters the brain soon after each eye movement. Many mammals make fast eye movements, but saccades reach higher velocities and are more frequent in primates tha ...
Hemispheric Differences in the Activation of
... ATTIC - BASEMENT). The authors hypothesized a hemispheric asymmetry
in semantic-relatedness judgments, based on the assumption that visual-spatial relations are
stored and processed in the right hemisphere. Participants were faster to make judgments in the
iconic condition than in the ...
... ATTIC
KISHORE Aswathy - School of Computing
... been conducted to obtain an understanding of the underlying mechanisms of the phenomenon. One important focus of these studies has been to understand how the brain represents the visual information that enters it through the eye. As a result of these studies, it can now be said with a fair amount of ...
... been conducted to obtain an understanding of the underlying mechanisms of the phenomenon. One important focus of these studies has been to understand how the brain represents the visual information that enters it through the eye. As a result of these studies, it can now be said with a fair amount of ...
Vision`s First Steps: Anatomy, Physiology, and Perception in the
... between the retina and the cortex. However, LGN neurons are part of a complex circuit that involves ascending, descending and recurrent sets of neuronal connections [5, 194, 201]. The major source of descending input comes from neurons in layer 6 of V1. These feedback connections can be excitatory ( ...
... between the retina and the cortex. However, LGN neurons are part of a complex circuit that involves ascending, descending and recurrent sets of neuronal connections [5, 194, 201]. The major source of descending input comes from neurons in layer 6 of V1. These feedback connections can be excitatory ( ...
Stimulus-Dependent Synchronization of Neuronal Responses in the
... evoked by the same stimulus are expected to contain such synchronous episodes much more frequently than responses evoked by different stimuli. To test this prediction, we investigated response synchronization in the middle temporal area (area V5 or MT) of alert fixating macaque monkeys. This area is ...
... evoked by the same stimulus are expected to contain such synchronous episodes much more frequently than responses evoked by different stimuli. To test this prediction, we investigated response synchronization in the middle temporal area (area V5 or MT) of alert fixating macaque monkeys. This area is ...
Comparison of Quantities: Core and Format
... compare either numbers or nondiscrete quantities. Their analysis identified the left IPS as the center of a network responsive to magnitude. Rather than focusing on common regions, Venkatraman et al. (2005) used an arithmetical task to reveal the areas that respond differentially when participants pr ...
... compare either numbers or nondiscrete quantities. Their analysis identified the left IPS as the center of a network responsive to magnitude. Rather than focusing on common regions, Venkatraman et al. (2005) used an arithmetical task to reveal the areas that respond differentially when participants pr ...
Limitations of Neural Map Topography for Decoding Spatial
... are equivalent to step functions in our one-dimensional model. To generate responses for decoding, we presented each stimulus to the model 50 times, for a total of 150 presentations. The response ri of each tectal cell to each presentation of each stimulus was recorded. Decoding was performed as des ...
... are equivalent to step functions in our one-dimensional model. To generate responses for decoding, we presented each stimulus to the model 50 times, for a total of 150 presentations. The response ri of each tectal cell to each presentation of each stimulus was recorded. Decoding was performed as des ...
How Reliably Does a Neuron in the Visual Motion Pathway of fhe Fly
... behavioural situation the animal's own actions and reactions have immediate consequences on its sensory input. Therefore, the SIRC is not simply the consequence of an external source but is determined, at least to a large extent, by the animal itself. Hence, in order to assess the functional signifi ...
... behavioural situation the animal's own actions and reactions have immediate consequences on its sensory input. Therefore, the SIRC is not simply the consequence of an external source but is determined, at least to a large extent, by the animal itself. Hence, in order to assess the functional signifi ...
Brain oscillations in perception and memory
... Stimulation is applied at time ‘0 ms’. ŽB. Ten single EEG-EP trials, digitally filtered Ž30]50 Hz. and selected for high enhancement, i.e. high amplitude increase after stimulus Žin comparison with prestimulus EEG amplitude.. UU , average of these trials. ŽC. Selectively averaged evoked potentials Ž ...
... Stimulation is applied at time ‘0 ms’. ŽB. Ten single EEG-EP trials, digitally filtered Ž30]50 Hz. and selected for high enhancement, i.e. high amplitude increase after stimulus Žin comparison with prestimulus EEG amplitude.. UU , average of these trials. ŽC. Selectively averaged evoked potentials Ž ...
Visual Fields in Ophthalmology - New York Eye and Ear Infirmary
... • Stationary object presented at different locations • Intensity increased or decreased to establish threshold* value ...
... • Stationary object presented at different locations • Intensity increased or decreased to establish threshold* value ...
Perceptual and Semantic Contributions to
... discrimination of objects. Plus, the localization of these repetition suppression effects was predominantly within brain regions of the left middle temporal cortices (for evidence from an adaptation paradigm, see also Altmann et al. 2007), whereas the earlier categorical effects predominantly modula ...
... discrimination of objects. Plus, the localization of these repetition suppression effects was predominantly within brain regions of the left middle temporal cortices (for evidence from an adaptation paradigm, see also Altmann et al. 2007), whereas the earlier categorical effects predominantly modula ...
Visual and presaccadic activity in area 8Ar of the macaque monkey
... fixation point (0.08 degrees2) and pressed a lever to indicate willingness to start the trial. After ...
... fixation point (0.08 degrees2) and pressed a lever to indicate willingness to start the trial. After ...
Vision in Drosophila - University of Queensland
... One striking aspect of Drosophila vision research is how simple the behavioral paradigms often are, compared with the complexity of the underlying circuits introduced above. Again, this is because initial approaches to vision were necessarily reductionist. These assays often involved fly populations ...
... One striking aspect of Drosophila vision research is how simple the behavioral paradigms often are, compared with the complexity of the underlying circuits introduced above. Again, this is because initial approaches to vision were necessarily reductionist. These assays often involved fly populations ...
Spatial Responsiveness of Monkey Hippocampal Neurons to
... Andersen, 1987; Goldman-Rakic, 19871, mainly via the parahippocampal cortices (PH) (Jones and Powell, 1970; Van Hoesen, 1982; Amaral, 1987; Tranel et al., 1988). Recent results indicate that the HF, and the system to which it belongs, are essential for acquisition, relation, combination, and conjunc ...
... Andersen, 1987; Goldman-Rakic, 19871, mainly via the parahippocampal cortices (PH) (Jones and Powell, 1970; Van Hoesen, 1982; Amaral, 1987; Tranel et al., 1988). Recent results indicate that the HF, and the system to which it belongs, are essential for acquisition, relation, combination, and conjunc ...
Visual speech circuits in profound acquired
... task but deaf patients activated the left posterior superior temporal cortex more than controls. This effect correlated with speechreading fluency but not with the duration of sensory deprivation, thus arguing against long-term reorganization as the source of these cross-modal effects. To the contra ...
... task but deaf patients activated the left posterior superior temporal cortex more than controls. This effect correlated with speechreading fluency but not with the duration of sensory deprivation, thus arguing against long-term reorganization as the source of these cross-modal effects. To the contra ...
Models of Information Processing in the Visual Cortex
... First, models can represent a selected part of the world, and second, models can represent a theory. The two notions are not mutually exclusive, but they provide a good distinction between more practical models trying to reproduce a certain system, and more theoretical models constrained to a certai ...
... First, models can represent a selected part of the world, and second, models can represent a theory. The two notions are not mutually exclusive, but they provide a good distinction between more practical models trying to reproduce a certain system, and more theoretical models constrained to a certai ...
The continuous performance test: a window on
... frontal cortex is seen as resulting from their respective inputs into the association areas, which in turn impact on the inferior parietal lobes to inhibit or facilitate attentional response. The posterior parietal lobe takes on increased importance with regard to visual and spatial information. As ...
... frontal cortex is seen as resulting from their respective inputs into the association areas, which in turn impact on the inferior parietal lobes to inhibit or facilitate attentional response. The posterior parietal lobe takes on increased importance with regard to visual and spatial information. As ...
Segregation and convergence of specialised pathways in
... At the level of cortical area V2, the various visual inputs to the cortex have reorganised to form 3 distinct channels. Anatomically these are embodied in the thick and thin dark stripes, and paler interstripes characteristic of cytochrome oxidase architecture. Do the outputs of these compartments r ...
... At the level of cortical area V2, the various visual inputs to the cortex have reorganised to form 3 distinct channels. Anatomically these are embodied in the thick and thin dark stripes, and paler interstripes characteristic of cytochrome oxidase architecture. Do the outputs of these compartments r ...
Brain Research, 178 (1979) 363-380 363 © Elsevier/North
... a small number of dictinct action potentials and an unresolved background. We refer to this activity as 'multi-unit activity' (see Figs. 2 and 6). Normally, in 2 mm of travel through cortex, 2-4 multi-unit clusters were studied. The animal was stimulated visually and the electrode advanced continuou ...
... a small number of dictinct action potentials and an unresolved background. We refer to this activity as 'multi-unit activity' (see Figs. 2 and 6). Normally, in 2 mm of travel through cortex, 2-4 multi-unit clusters were studied. The animal was stimulated visually and the electrode advanced continuou ...
Nerve growth factor improves visual loss in childhood optic
... Paediatric optic pathway gliomas are low-grade brain tumours characterized by slow progression and invalidating visual loss. Presently there is no strategy to prevent visual loss in this kind of tumour. This study evaluated the effects of nerve growth factor administration in protecting visual funct ...
... Paediatric optic pathway gliomas are low-grade brain tumours characterized by slow progression and invalidating visual loss. Presently there is no strategy to prevent visual loss in this kind of tumour. This study evaluated the effects of nerve growth factor administration in protecting visual funct ...
Toward a Unified Theory of Visual Area V4
... not correspond to our perception of ‘‘red’’ ‘‘green’’ and ‘‘blue’’; rather, our perception of color requires multiple stages of L, M, S input integration (Chatterjee and Callaway, 2003; Gegenfurtner and Kiper, 2003; Solomon and Lennie, 2007; Conway et al., 2010). An important early stage is the gene ...
... not correspond to our perception of ‘‘red’’ ‘‘green’’ and ‘‘blue’’; rather, our perception of color requires multiple stages of L, M, S input integration (Chatterjee and Callaway, 2003; Gegenfurtner and Kiper, 2003; Solomon and Lennie, 2007; Conway et al., 2010). An important early stage is the gene ...
Alterations to multisensory and unisensory integration by stimulus
... and within-modal blocks. Figure 1 illustrates the difference between simple and competing stimulus configurations. An interstimulus interval of 5– 6.5 s was used to minimize habituation. Data acquisition and analysis. Custom software was used to acquire raw data waveforms and impulses from single ne ...
... and within-modal blocks. Figure 1 illustrates the difference between simple and competing stimulus configurations. An interstimulus interval of 5– 6.5 s was used to minimize habituation. Data acquisition and analysis. Custom software was used to acquire raw data waveforms and impulses from single ne ...
Document
... here, the same background is always used, and it is always in the same position, with stimuli moved to different positions on it. The nine stimulus locations are arranged in a square grid across the background, where the grid spacings are 32 pixels horizontally or vertically. Before images are prese ...
... here, the same background is always used, and it is always in the same position, with stimuli moved to different positions on it. The nine stimulus locations are arranged in a square grid across the background, where the grid spacings are 32 pixels horizontally or vertically. Before images are prese ...
Sensory uncertainty decoded from visual cortex
... of physically identical orientation stimuli. We reasoned that, if the posterior distribution also captures random, trial-by-trial fluctuations in cortical activity, then more certain decoder estimates should be linked to reduced variability in the observer’s behavior, even for physically identical o ...
... of physically identical orientation stimuli. We reasoned that, if the posterior distribution also captures random, trial-by-trial fluctuations in cortical activity, then more certain decoder estimates should be linked to reduced variability in the observer’s behavior, even for physically identical o ...
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.