To determine whether visual perceptual measures in people who experience snow are consistent with an imbalance between inhibition and excitation cortex.Sixteen patients 18 controls participated. Four tasks were included: center-surround contrast matching, luminance increment detection noise, global form motion coherence thresholds. Neuronal architecture capable of encoding the stimuli is present within primary cortex, whereas extraction signals requires extrastriate processing. All these...

Abstract Previous research provides conflicting evidence regarding whether older adults have altered tolerance to timing differences between auditory and visual events. We examine the potential impact of age-related unisensory decline on audiovisual synchrony perception. Fifteen younger (21–32 years) 13 (60–72 participated. To assess sensitivity, Gabor contrast detection thresholds masked tone pip were measured. Four multisensory conditions then tested: suprathreshold near-threshold stimuli...

Background Several visual tasks have been proposed as indirect assays of the balance between cortical inhibition and excitation in migraine. This study aimed to determine whether daily measurement performance on such can reveal perceptual changes build up migraine events. Methods Visual was measured at home 16 non-headache controls 18 individuals with using a testing protocol portable tablet device. Observers performed two tasks: luminance increment detection spatial noise centre surround...

Perceived synchrony of visual and auditory signals can be altered by exposure to a stream temporally offset stimulus pairs. Previous literature suggests that adapting audiovisual temporal offsets is an important recalibration correctly combine stimuli into single percept across range source distances. Healthy aging results in perception over wider signals, independent age-related unisensory declines vision hearing sensitivities. However, the impact on unknown. Audiovisual for sound-lead...

Purpose: Visual snow is the hallmark of neurological condition visual syndrome (VSS) but characteristics percept remain poorly defined. This study aimed to quantify its appearance, interobserver variability, and effect on measured performance self-reported quality. Methods: Twenty-three participants with VSS estimated their dot size, separation, luminance, flicker rate by matching a simulation. To assess whether masks vision, we compared pattern discrimination thresholds for textures that...

Certain perceptual measures have been proposed as indirect assays of brain neurochemical status in people with migraine. One such measure is binocular rivalry, however, previous studies not measured rivalry characteristics and neurochemistry together This study compared spectroscopy-measured levels GABA Glx (glutamine glutamate complex) visual cortex between 16 migraine non-headache controls, assessed whether the concentration these neurochemicals explains, at least partially,...

Visual snow syndrome is a neurological condition characterized by persistent visual disturbance, snow, in conjunction with additional symptoms. Cortical hyperexcitability potential pathophysiological mechanism, which could be explained increased gain neural responses to input. Alternatively, noise the pathway abnormally elevated. We assessed these two competing mechanisms our studies of contrast perception. hyperexcitation also occurs migraine, commonly co-occurs syndrome. Therefore,...

Abstract Normal aging has been shown to alter performance on several suprathreshold spatial tasks such as contour integration and perceptual measures of center-surround interactions. The purpose this study was investigate the effects collinear facilitation. Despite all related lateral interactions that are presumed involve neural architecture within primary visual cortex, facilitation differs from surround suppression in it is a purely foveal, threshold phenomenon. Collinear measured for 20...

Background: Visual Snow (VS) syndrome is believed to be due aberrant central visual processing. Positron Emission Tomography (PET) brain imaging and evoked potential studies provide evidence for excessive neuronal activity in the medial temporal lobe, specifically lingual gyrus, suggest VS a hyperexcitability syndrome. These data basis consideration of repetitive transcranial magnetic stimulation (rTMS) as treatment Objective: To publish study protocol pilot underway at University Colorado...

Purpose: Altered visual processing of motion and contrast has been previously reported in people with migraine. One possible manifestation this altered is increased self-reported susceptibility to illusions motion. Here, we use the Fraser–Wilcox illusion explore individual differences strength without The motion-inducing mechanisms are purported be dependent. To better understand illusion, as well anomalies migraine, explored whether migraine status, discomfort, discrimination, or...

Objective This study aimed to determine whether the visual response flickering checkerboard patterns measured using electroencephalography (EEG) relate excitatory or inhibitory metabolite levels ultra-high (7Tesla/7T) magnetic resonance spectroscopy (MRS). Background Electrophysiological studies have shown altered cortical amplitudes and contrast gain responses high in people with migraine. These anomalies been argued represent an imbalance between inhibition excitation, however specific...

Exposure to a stream of temporally offset visual and auditory signals changes an observers' perception synchrony. Previous literature suggests that adapting audiovisual temporal offsets is needed correctly combine stimuli into single percept for range source distances. Older people have wider synchrony windows, i.e. are more likely perceive sound with larger offsets. The impact ageing on recalibration unclear. Audiovisual sound-lead sound-lag was measured fifteen younger (22-32years old)...

Abstract Certain perceptual measures have been proposed as indirect assays of brain neurochemical status in people with migraine. One such measure is binocular rivalry, however, previous studies not measured rivalry characteristics and neurochemistry together This study compared spectroscopy-measured levels GABA Glx (glutamine glutamate complex) visual cortex between 16 migraine non-headache controls, assessed whether the concentration these neurochemicals explains, at least partially,...

Collinear facilitation is a visual phenomenon by which the contrast detection threshold of central target reduced (facilitation) when placed equidistant between two high-contrast flankers. The neural mechanisms underpinning this originate from feed-forward lateral cell layers in V1 (slower) and feedback extrastriate areas to (faster). strength these contributions has been explored younger adults presenting flankers at varying timing offsets. Here, we investigated effects older age on...