Re-Examining the Mental Imagery Debate with Neuropsychological
... impairment in Executive Functions (thus higher order visual reasoning) has little to no effect on an individual’s handwriting compared to the massive differences in their spatial reasoning, ergo ‘shapes’ are easier to mentally represent than ‘sizes’. This helps in the claim of spatial reasoning that ...
... impairment in Executive Functions (thus higher order visual reasoning) has little to no effect on an individual’s handwriting compared to the massive differences in their spatial reasoning, ergo ‘shapes’ are easier to mentally represent than ‘sizes’. This helps in the claim of spatial reasoning that ...
Impact on Perception, Attention, and Memory
... the notion that the mechanisms of emotion and cognition can be separated and investigated independently. This assumption has been challenged as behavioral science has started to incorporate methods from neuroscience. One of the striking characteristics of the brain is the extensive connectivity betw ...
... the notion that the mechanisms of emotion and cognition can be separated and investigated independently. This assumption has been challenged as behavioral science has started to incorporate methods from neuroscience. One of the striking characteristics of the brain is the extensive connectivity betw ...
Features of Neuronal Synchrony in Mouse Visual Cortex
... per condition and recording site with a bin size of 1 ms. To avoid inclusion of nonstationary, phasic response components, the first 200 ms after visual stimulus onset were discarded before analysis. In addition, shift-predictor correlograms were calculated. Since these were consistently flat, quant ...
... per condition and recording site with a bin size of 1 ms. To avoid inclusion of nonstationary, phasic response components, the first 200 ms after visual stimulus onset were discarded before analysis. In addition, shift-predictor correlograms were calculated. Since these were consistently flat, quant ...
Visual adaptation: Neural, psychological and computational aspects
... and Simoncelli (2006a) showed that human performance on a trial-by-trial basis is well explained by a Bayesian observer model that is optimal with respect to uncertainty reflected in the encoded sensory signals, where uncertainty includes external (stimulus) as well as internal (neural) noise. If the ...
... and Simoncelli (2006a) showed that human performance on a trial-by-trial basis is well explained by a Bayesian observer model that is optimal with respect to uncertainty reflected in the encoded sensory signals, where uncertainty includes external (stimulus) as well as internal (neural) noise. If the ...
Transcripts/2_4 1
... hemianopia. Left because it is a visual field defect (when you talk about defects it is always about the visual field, not the retina). You can’t see to the left, half of the visual field, and it is homonymous (same in both eyes). You would have the same thing if you took out the entire primary visu ...
... hemianopia. Left because it is a visual field defect (when you talk about defects it is always about the visual field, not the retina). You can’t see to the left, half of the visual field, and it is homonymous (same in both eyes). You would have the same thing if you took out the entire primary visu ...
Investigating neural correlates of conscious perception by frequency
... 8.33 Hz (f2), the flicker frequency of s2. The peak is confined to 1 frequency bin (0.0032 Hz). The SNR, defined as the ratio of the power at the peak and the average power in a 0.06 Hz band (40 bins) surrounding it, is 25.0 (7.41 Hz, anterior channel), 29.7 (8.33 Hz, anterior channel), 39.2 (7.41 H ...
... 8.33 Hz (f2), the flicker frequency of s2. The peak is confined to 1 frequency bin (0.0032 Hz). The SNR, defined as the ratio of the power at the peak and the average power in a 0.06 Hz band (40 bins) surrounding it, is 25.0 (7.41 Hz, anterior channel), 29.7 (8.33 Hz, anterior channel), 39.2 (7.41 H ...
Cross-Modal Transfer of Information between the Tactile
... In tactile–visual matching of three-dimensional objects, the tactile information is of a different nature from that of visual information. When the hand is used to palpate an object, the information is sampled in a piecemeal manner, such that only a part of the object surface is covered by the finge ...
... In tactile–visual matching of three-dimensional objects, the tactile information is of a different nature from that of visual information. When the hand is used to palpate an object, the information is sampled in a piecemeal manner, such that only a part of the object surface is covered by the finge ...
Seeing faces and objects with the “mind`s eye”
... parietal cortex, to occipito-temporal cortex were category-selective (Fig. 1). Thus, the DCM analysis revealed that dynamic neuronal interactions between occipito-temporal, parietal and frontal regions are task- and stimulus-dependent. Sensory representations of faces and objects in ventral extrastr ...
... parietal cortex, to occipito-temporal cortex were category-selective (Fig. 1). Thus, the DCM analysis revealed that dynamic neuronal interactions between occipito-temporal, parietal and frontal regions are task- and stimulus-dependent. Sensory representations of faces and objects in ventral extrastr ...
Visual Cortex and Control Processes Stimuli in Opposite Visual
... of three letters presented for 200 ms either unilaterally or bilaterally. Unilateral displays resulted in greater contralateral occipital activations than bilateral displays. This was taken as direct evidence that inter-hemispheric sensory competition can arise between stimuli in opposite visual hem ...
... of three letters presented for 200 ms either unilaterally or bilaterally. Unilateral displays resulted in greater contralateral occipital activations than bilateral displays. This was taken as direct evidence that inter-hemispheric sensory competition can arise between stimuli in opposite visual hem ...
Interactions between attention, context and learning in primary
... plexus of long range horizontal connections that link cells with widely separated receptive fields. This is a network of connectivity formed by the axons of cortical pyramidal cells. Pyramidal and spiny stellate cells represent 80% of the neurons in the cortex, each cell can form lateral connections ...
... plexus of long range horizontal connections that link cells with widely separated receptive fields. This is a network of connectivity formed by the axons of cortical pyramidal cells. Pyramidal and spiny stellate cells represent 80% of the neurons in the cortex, each cell can form lateral connections ...
Visual and oculomotor selection: links, causes and
... Figure 2. Microstimulation of the SC. Two recent studies examined the effect of subthreshold SC microstimulation (left) on covert spatial attention. (a) One study used a change-blindness task in which monkeys were trained to detect peripheral changes in a visual display. During each trial the animal ...
... Figure 2. Microstimulation of the SC. Two recent studies examined the effect of subthreshold SC microstimulation (left) on covert spatial attention. (a) One study used a change-blindness task in which monkeys were trained to detect peripheral changes in a visual display. During each trial the animal ...
Modulation of early cortical processing during divided attention to
... owing to the low temporal resolution of the methods employed, these studies are not suitable for investigating whether or not any cost involved in splitting the spotlight might impact on the precise temporal locus of attention, i.e. whether the modulation might occur during initial feedforward proce ...
... owing to the low temporal resolution of the methods employed, these studies are not suitable for investigating whether or not any cost involved in splitting the spotlight might impact on the precise temporal locus of attention, i.e. whether the modulation might occur during initial feedforward proce ...
When the Sun Prickles Your Nose: An EEG Study Identifying
... ophthalmoscope, photographic flash, or ultraviolet light, should also cause a sneeze. The photic sneeze reflex is clearly in need of study, especially in view of its high prevalence. A Swedish blood donor study [5] investigated one of the largest representative samples of subjects and reported photi ...
... ophthalmoscope, photographic flash, or ultraviolet light, should also cause a sneeze. The photic sneeze reflex is clearly in need of study, especially in view of its high prevalence. A Swedish blood donor study [5] investigated one of the largest representative samples of subjects and reported photi ...
Uncomfortable images produce non-sparse responses in a model of
... models of populations of neurons with properties similar to those found in the visual cortex have been shown to produce sparse responses to natural image inputs [4]. Equally, learning algorithms that seek to generate sparse responses to natural image samples produce units with receptive fields that ...
... models of populations of neurons with properties similar to those found in the visual cortex have been shown to produce sparse responses to natural image inputs [4]. Equally, learning algorithms that seek to generate sparse responses to natural image samples produce units with receptive fields that ...
Neural correlates of attention in primate visual cortex
... effects in the presumed human homolog31–33. By now, imaging studies had traced these attentional effects on motion processing all the way back to V1 (Refs 34,35). Taken together, these studies demonstrate that attention influences processing in both pathways from the beginning, but they also indicat ...
... effects in the presumed human homolog31–33. By now, imaging studies had traced these attentional effects on motion processing all the way back to V1 (Refs 34,35). Taken together, these studies demonstrate that attention influences processing in both pathways from the beginning, but they also indicat ...
Perception of Motion, Depth, and Form
... N vISIoN,AS IN orHERmental oPerations, we exPerrence the world as a whole. Independent attributesmotion, depth, form, and color-are coordinated into a single visual image. In the two Previous chapters we began to consider how two parallel Pathways-the magnocellular and parvocellular pathways, that e ...
... N vISIoN,AS IN orHERmental oPerations, we exPerrence the world as a whole. Independent attributesmotion, depth, form, and color-are coordinated into a single visual image. In the two Previous chapters we began to consider how two parallel Pathways-the magnocellular and parvocellular pathways, that e ...
Beyond the classical receptive field: The effect of contextual stimuli
... In a previous paper (Spillmann, 2014), the early history of the receptive field (RF) concept was reviewed, recounting the seminal studies of optic nerve responses in the frog (Hartline 1938, 1940; Barlow, 1953) and cat (Kuffler, 1953; Barlow, Fitzhugh, & Kuffler, 1957) as well as the systematic studies ...
... In a previous paper (Spillmann, 2014), the early history of the receptive field (RF) concept was reviewed, recounting the seminal studies of optic nerve responses in the frog (Hartline 1938, 1940; Barlow, 1953) and cat (Kuffler, 1953; Barlow, Fitzhugh, & Kuffler, 1957) as well as the systematic studies ...
Cortical mechanisms of sensory learning and object recognition
... Change could also occur in upstream areas, as a cascade moving in the reverse direction of signal propagation during stimulus processing. According to this reverse hierarchy theory (Ahissar & Hochstein 2004), the broad spectrum of responses initially passed on to a ‘downstream’ target area narrows a ...
... Change could also occur in upstream areas, as a cascade moving in the reverse direction of signal propagation during stimulus processing. According to this reverse hierarchy theory (Ahissar & Hochstein 2004), the broad spectrum of responses initially passed on to a ‘downstream’ target area narrows a ...
“Black” Responses Dominate Macaque Primary Visual Cortex
... average unit distance from the two measures. Therefore, factors such as the shrinkage of the brain section would not affect our estimates substantially. The mean thickness of each layer was then used to determine each cell’s normalized cortical depth. The assignment of cells to layers is crucial sin ...
... average unit distance from the two measures. Therefore, factors such as the shrinkage of the brain section would not affect our estimates substantially. The mean thickness of each layer was then used to determine each cell’s normalized cortical depth. The assignment of cells to layers is crucial sin ...
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 ...
The representation of Kanizsa illusory contours in the monkey
... Illusory shape coding in the IT cortex 2139 The fixation spot remained on the screen for a further 100–300 ms after the end of the stimulus and drops of fruit juice or water were given as reward. Single cells were isolated using the LD stimuli by advancing the electrode with a hydraulic microdrive ( ...
... Illusory shape coding in the IT cortex 2139 The fixation spot remained on the screen for a further 100–300 ms after the end of the stimulus and drops of fruit juice or water were given as reward. Single cells were isolated using the LD stimuli by advancing the electrode with a hydraulic microdrive ( ...
Visual hallucinations in the differential diagnosis - JNNP
... of the functional imaging studies have been contradictory44 45 but some correlate with anatomical predictions.46 For example, reduced glucose metabolism shown on fluorodeoxyglucoseepositron emission tomography in the ventral right temporal lobe and the right lateral visual cortex in PD suggests a fun ...
... of the functional imaging studies have been contradictory44 45 but some correlate with anatomical predictions.46 For example, reduced glucose metabolism shown on fluorodeoxyglucoseepositron emission tomography in the ventral right temporal lobe and the right lateral visual cortex in PD suggests a fun ...
Topographic maps in human frontal and parietal cortex
... Subsequent investigations have used a variety of experimental paradigms including a visual spatial attention task [19], presentation of a colorful and dynamic periodic mapping stimulus [11], and a variation of the memoryguided saccade task originally used by Sereno and colleagues [20,21] to characte ...
... Subsequent investigations have used a variety of experimental paradigms including a visual spatial attention task [19], presentation of a colorful and dynamic periodic mapping stimulus [11], and a variation of the memoryguided saccade task originally used by Sereno and colleagues [20,21] to characte ...
Mechanisms of Visual Attention in the Human Cortex
... stimuli were shown to be a weighted average of the responses to the individual stimuli presented alone. For example, if a single good stimulus elicited a high firing rate and a single poor stimulus elicited a low firing rate, the response to the paired stimuli was reduced compared with that elicited ...
... stimuli were shown to be a weighted average of the responses to the individual stimuli presented alone. For example, if a single good stimulus elicited a high firing rate and a single poor stimulus elicited a low firing rate, the response to the paired stimuli was reduced compared with that elicited ...
... is constitutively operative and not related to extinction, and thereby cause extinguished (or perhaps partially extinguished) responses to resume. Signs of such constitutive inhibition might not be noticeable in unconditioned FraidyRat because in them there might be no excitation to be inhibited, a ...
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.