Two Critical and Functionally Distinct Stages of Face and Body Perception
... Cortical regions that respond preferentially to particular object categories, such as faces and bodies, are essential for visual perception of these object categories. However, precisely when these regions play a causal role in recognition of their preferred categories is unclear. Here we addressed ...
... Cortical regions that respond preferentially to particular object categories, such as faces and bodies, are essential for visual perception of these object categories. However, precisely when these regions play a causal role in recognition of their preferred categories is unclear. Here we addressed ...
Receptive fields and suppressive fields in the
... Murphy and Sillito, 1987), however, were inadequate stimuli to study this reduction; with such stimuli it is not clear if response reduction could be simply explained by the antagonistic surround of the receptive field or if it constituted an unexplained suppressive phenomenon. Nonetheless, these re ...
... Murphy and Sillito, 1987), however, were inadequate stimuli to study this reduction; with such stimuli it is not clear if response reduction could be simply explained by the antagonistic surround of the receptive field or if it constituted an unexplained suppressive phenomenon. Nonetheless, these re ...
The Effects of Short-term and Long-term Learning on the Responses
... area LIP, we note that Ben Hamed et al. (2001) mapped the location selectivity of LIP neurons with well-defined visual responses (regardless of the presence of delay period or eye movement-related activity) and reported that 11.7% of their 171 LIP neurons had the center of mass of their radio freque ...
... area LIP, we note that Ben Hamed et al. (2001) mapped the location selectivity of LIP neurons with well-defined visual responses (regardless of the presence of delay period or eye movement-related activity) and reported that 11.7% of their 171 LIP neurons had the center of mass of their radio freque ...
Action Preparation Shapes Processing in Early Visual Cortex
... examine whether action preparation modulates activity in early human visual cortex, subjects grasped or pointed to oriented objects while high-resolution fMRI data were acquired. Using multivoxel pattern analysis techniques, we could decode with ⬎70% accuracy whether a ...
... examine whether action preparation modulates activity in early human visual cortex, subjects grasped or pointed to oriented objects while high-resolution fMRI data were acquired. Using multivoxel pattern analysis techniques, we could decode with ⬎70% accuracy whether a ...
A Subjective Distance Between Stimuli: Quantifying the Metric
... definite matrix representing the scalar product. Condition 4 imposes symmetry among the components of the vectors, which means that M must be proportional to the unit matrix. Therefore, out of all the distances that have a scalar product associated with them, the only one that fulfills condition 4 i ...
... definite matrix representing the scalar product. Condition 4 imposes symmetry among the components of the vectors, which means that M must be proportional to the unit matrix. Therefore, out of all the distances that have a scalar product associated with them, the only one that fulfills condition 4 i ...
Extended PDF
... Human observers typically integrate sensory signals in a statistically optimal fashion into a coherent percept by weighting them in proportion to their reliabilities [1–4]. An emerging debate in neuroscience is to which extent multisensory integration emerges already in primary sensory areas or is d ...
... Human observers typically integrate sensory signals in a statistically optimal fashion into a coherent percept by weighting them in proportion to their reliabilities [1–4]. An emerging debate in neuroscience is to which extent multisensory integration emerges already in primary sensory areas or is d ...
Multisensory Integration in the Ventral Intraparietal Area of the
... Materials and Methods Surgical preparation. Two adult rhesus monkeys (Macaca mulatta, monkeys N and M), weighing 4.5 and 6.5 kg, were used in this study. Procedures were approved by the local Animal Care Committee in compliance with the guidelines of European Community on Animal Care. Animals were p ...
... Materials and Methods Surgical preparation. Two adult rhesus monkeys (Macaca mulatta, monkeys N and M), weighing 4.5 and 6.5 kg, were used in this study. Procedures were approved by the local Animal Care Committee in compliance with the guidelines of European Community on Animal Care. Animals were p ...
Linking Neural Activity to Visual Perception: Separating Sensory and
... discrimination sensitivity of MT neurons in the 2AFC task (see Appendix). For this, two distributions of spike counts were compared against each other, the distribution of counts from trials when the coherent motion was in the neuron’s preferred direction (distribution Y in Figure 2A) versus the dis ...
... discrimination sensitivity of MT neurons in the 2AFC task (see Appendix). For this, two distributions of spike counts were compared against each other, the distribution of counts from trials when the coherent motion was in the neuron’s preferred direction (distribution Y in Figure 2A) versus the dis ...
Center-Surround Interactions in the Middle Temporal Visual Area of
... opposite types of center-surround interaction with respect to moving visual stimuli. In one type of column, neurons responded well to objects such as a single bar or spot but poorly to large textured stimuli such as random dots. This was often due to the fact that the receptive fields had antagonist ...
... opposite types of center-surround interaction with respect to moving visual stimuli. In one type of column, neurons responded well to objects such as a single bar or spot but poorly to large textured stimuli such as random dots. This was often due to the fact that the receptive fields had antagonist ...
A perceptual representation in the frontal eye field during covert
... locations in the search array (Fig. 1A). For a trial to count as valid, the monkey was required to grasp the lever and maintain it at a center position, fixate the central spot (400–800 ms), wait for the search array to appear and, while maintaining fixation on the central spot, turn the lever to repo ...
... locations in the search array (Fig. 1A). For a trial to count as valid, the monkey was required to grasp the lever and maintain it at a center position, fixate the central spot (400–800 ms), wait for the search array to appear and, while maintaining fixation on the central spot, turn the lever to repo ...
Tuning Curve Shift by Attention Modulation in Cortical Neurons: a
... shrinking factor. Without attention, the neuron at x has a symmetric, bell-shaped receptive field and its maximum response occurs when the stimulus is presented at x. Under attention, the receptive field might shift and/or change size. In order to assess the shift of the receptive field we typically us ...
... shrinking factor. Without attention, the neuron at x has a symmetric, bell-shaped receptive field and its maximum response occurs when the stimulus is presented at x. Under attention, the receptive field might shift and/or change size. In order to assess the shift of the receptive field we typically us ...
Word - Jim Davies
... stop-translation) are changes to the dynamic behavior of the system under simulation. For example, rotate changes the initial orientation of an element, but in contrast startrotating sets an element in motion. The fortress/tumor example requires two transformations. The first is to decompose the arm ...
... stop-translation) are changes to the dynamic behavior of the system under simulation. For example, rotate changes the initial orientation of an element, but in contrast startrotating sets an element in motion. The fortress/tumor example requires two transformations. The first is to decompose the arm ...
Contributions of cortical feedback to sensory processing in primary
... a challenge to feedforward theories of vision. The role of internal models in mediating predictive processing has been suggested by data from ferret V1, where, over development, spontaneous activity becomes increasingly similar to the activation induced by natural scenes (Berkes et al., 2011). This ...
... a challenge to feedforward theories of vision. The role of internal models in mediating predictive processing has been suggested by data from ferret V1, where, over development, spontaneous activity becomes increasingly similar to the activation induced by natural scenes (Berkes et al., 2011). This ...
Effect of Spatial Attention on the Responses of Area MT Neurons
... attention on the responses of area MT neurons. J. Neurophysiol. 81: 1783–1794, 1999. This study examines the influence of spatial attention on the responses of neurons in the middle temporal visual area (MT or V5) of extrastriate cortex. Two monkeys were trained to perform a direction-discrimination ...
... attention on the responses of area MT neurons. J. Neurophysiol. 81: 1783–1794, 1999. This study examines the influence of spatial attention on the responses of neurons in the middle temporal visual area (MT or V5) of extrastriate cortex. Two monkeys were trained to perform a direction-discrimination ...
The Number of Cortical Neurons Used to See
... My results set a substantial lower bound (50) on the number of cortical cells contributing to seeing. The results of this study are an important step toward unraveling how we use neurons to see. 1.1 Primary Visual Cortex: simple and complex cells The retina is sensitive to light. It sends signals, b ...
... My results set a substantial lower bound (50) on the number of cortical cells contributing to seeing. The results of this study are an important step toward unraveling how we use neurons to see. 1.1 Primary Visual Cortex: simple and complex cells The retina is sensitive to light. It sends signals, b ...
Anatomical Evidence of Multimodal Integration in Primate
... Injections of tracers. Thirteen retrograde tracing experiments were performed on nine cynomolgus monkeys (Macaca fascicularis; Table 1). After premedication with atropine (1.25 mg, i.m.) and dexamethasone (4 mg, i.m.), monkeys were prepared for surgery under ketamine hydrochloride (20 mg / kg, i.m.) ...
... Injections of tracers. Thirteen retrograde tracing experiments were performed on nine cynomolgus monkeys (Macaca fascicularis; Table 1). After premedication with atropine (1.25 mg, i.m.) and dexamethasone (4 mg, i.m.), monkeys were prepared for surgery under ketamine hydrochloride (20 mg / kg, i.m.) ...
The response of cat visual cortex to flicker stimuli of variable frequency
... peak and side peaks whose amplitude was related to the stimulation frequency and its harmonics in the same way as in the ACFs and CCFs computed between MUA and trigger pulses. In the CCFs between MUA responses from different electrodes, the amplitude and width of the centre peak provide a measure of ...
... peak and side peaks whose amplitude was related to the stimulation frequency and its harmonics in the same way as in the ACFs and CCFs computed between MUA and trigger pulses. In the CCFs between MUA responses from different electrodes, the amplitude and width of the centre peak provide a measure of ...
Soto-Faraco (2003) Multisensory contributions to the perception of
... to the question of how multisensory motion cues are integrated. This is because they do not specifically address the perceptual consequences of processing concurrent motion signals in different sensory modalities. There are, however, a number of studies that have more directly addressed the effects ...
... to the question of how multisensory motion cues are integrated. This is because they do not specifically address the perceptual consequences of processing concurrent motion signals in different sensory modalities. There are, however, a number of studies that have more directly addressed the effects ...
5655.full - Journal of Neuroscience
... presentations of emotional stimuli and emotion-associated fractals. We tested whether emotions could be decoded from fMRI signals evoked by the fractal stimuli using a classifier trained on the responses to the emotional stimuli (and vice versa). This was implemented as a whole-brain searchlight, mu ...
... presentations of emotional stimuli and emotion-associated fractals. We tested whether emotions could be decoded from fMRI signals evoked by the fractal stimuli using a classifier trained on the responses to the emotional stimuli (and vice versa). This was implemented as a whole-brain searchlight, mu ...
LINKING PROPOSITIONS*
... What is the place and value of sensory reports in the testing of physiological hypotheses? He formulated the argument that phenomenal terms and physiological terms are from different realms of discourse, and that, if terms from the two different realms were to be used together in a single sentence, ...
... What is the place and value of sensory reports in the testing of physiological hypotheses? He formulated the argument that phenomenal terms and physiological terms are from different realms of discourse, and that, if terms from the two different realms were to be used together in a single sentence, ...
Functional Clustering Drives Encoding Improvement in a
... awake tectum. (e) Simultaneous recording of somatic fluorescence (DF/F0, top) and action potentials (green) in response to full field light stimuli of varying intensity, with actual (gray) and inferred (black) firing rates in the 5 s following each stimulus. (f) Expanded voltage trace for electrophy ...
... awake tectum. (e) Simultaneous recording of somatic fluorescence (DF/F0, top) and action potentials (green) in response to full field light stimuli of varying intensity, with actual (gray) and inferred (black) firing rates in the 5 s following each stimulus. (f) Expanded voltage trace for electrophy ...
Saccade performance in the nasal and temporal
... of the right eye and the lateral rectus of the left eye. It is assumed that the OPNs synchronize the activity of the IBNs and EBNs before the saccade starts and it is important for the velocity of the of the saccade that the lateral and medial rectus of the left and right eyes, respectively, are in ...
... of the right eye and the lateral rectus of the left eye. It is assumed that the OPNs synchronize the activity of the IBNs and EBNs before the saccade starts and it is important for the velocity of the of the saccade that the lateral and medial rectus of the left and right eyes, respectively, are in ...
Segregation and convergence of specialised pathways in
... the inferior VM at the border with VI ...
... the inferior VM at the border with VI ...
The cognitive neuroscience of sustained attention
... complex high-level cognitive functions by successively lower neural levels of description benefits from neuroscientific research approaches, and that efforts to determine low-level neuronal mechanisms of cognitive functions benefit from cognitive construct-driven research in humans [25,63,76]. Furth ...
... complex high-level cognitive functions by successively lower neural levels of description benefits from neuroscientific research approaches, and that efforts to determine low-level neuronal mechanisms of cognitive functions benefit from cognitive construct-driven research in humans [25,63,76]. Furth ...
The medial parietal occipital areas in the macaque
... The number, location, extent, and functional properties of the cortical areas that occupy the medial parieto-occipital cortex (mPOC) have been, and still is, a matter of scientific debate. The mPOC is a convoluted region of the brain that presents a high level of individual variability, and the fact ...
... The number, location, extent, and functional properties of the cortical areas that occupy the medial parieto-occipital cortex (mPOC) have been, and still is, a matter of scientific debate. The mPOC is a convoluted region of the brain that presents a high level of individual variability, and the fact ...
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.