The detectability of the signal was measured in twoalternative forcedchoice tasks with different temporal envelopes. Population spatial frequency tuning in human early visual. Asher, jordi and romei, vincenzo and hibbard, paul 2019 spatial frequency tuning and transfer of perceptual learning for motion coherence reflects the tuning properties of global motion processing. Sensory and perceptual processes purdue university spatial frequency there is a similar effect for this odd grating a larger receptive field responds better to lower frequencies you can make the same kind of observations about. Orientation tuning depends on spatial frequency in mouse visual. Dynamics of spatial frequency tuning in mouse visual. Contrastdependent changes in spatial frequency tuning of. In both primates and cats, a shift of the neurons preferred spatial frequency has been observed from low frequencies early in the response to higher frequencies later in the response. Spatial frequency and orientation tuning dynamics in area. Auditory spatial tuning at the crossroads of the midbrain and. Gallant departments of psychology and molecular and cellular biology, university of california, berkeley, ca 94720. Hayes and colleagues 1986 found that the most informative spatial frequency band is located around 20 cfw when adults were tested at 2. Population spatial frequency tuning in human early visual cortex. To investigate the neural mechanisms mediating selectivity in the awake animal, we measured the temporal dynamics of sf and orientation tuning.
Recent studies have shown that cells in the primary visual cortex can, in addition to borders, also encode surface brightness. A comparison of spatial frequency tuning for judgments of eye. The use of spatial frequency information in face identi. We used only spatial frequencies that appeared to be resolvable from the gray wall experiments, such that the mean lateral position of the bee was significantly different from. Spatial frequency tuning of single units in macaque. Luminance, contrast and spatialfrequency tuning of the. Integration of curved contours operates at a narrower bandwidth. A spherical model for orientation and spatialfrequency. Size tuning in the absence of spatial frequency tuning in.
The spatial frequency is a measure of how often sinusoidal components as determined by the fourier transform of the structure repeat per unit of distance. During object recognition, the visual system can tune in to an appropriate size sensitive to spatial extent, rather than to variations in spatial frequency. Difference of spatial frequency selectivity between static and flicker motion aftereffects show all authors. However, recently, it has been shown that training on global motion. Spatial clustering of tuning in mouse primary visual cortex. Higgins 2, 3 1 graduate program in neuroscience, the university of arizona, 1040 e. The signals were vertical sinusoidal gratings of different spatial frequencies. This suggests that a cortical map of spatial frequency exists. In the wulst of the burrowing owl, a v1 analog in birds, similar temporal changes in spatial frequency tuning were observed. Volitional eye movements in addition to the spatial composition of the stimuli.
A grating of low spatial frequency few cycles within each degree of visual angle contains wide bars. In experiments 2ac, the sfs used for identifying upright and inverted inner facial features were investigated. The spatial frequency tuning of opticflowdependent. The spatial frequency tuning of opticflowdependent behaviors in the. Spatial frequency and image resolution java tutorial. In experiment 1, they validated the sf bubbles technique in a plaid detection task.
The spatiotemporal frequency tuning of lgn receptive field. A comparison of spatial frequency tuning for the recognition. Spatial frequency bandwidth of surround suppression tuning. We also compared the dynamics of spatial frequency tuning between v1 and the extrastriate lateromedial lm. The spatial frequency tuning of the transfer of learning suggests an important role for the higher level, global stage of motion processing. Bimodal tuning curve for spatial frequency across left and. Lgn responses are largely lowpass in spatial frequency, whereas the majority of v1 neurons have bandpass characteristics. Correlation of local and global orientation and spatial frequency. Vision free fulltext spatial frequency tuning and transfer of. In addition to changing the gaussian envelope spread, the carrier frequency of the gabor. Spatial frequency tuning as a function of temporal frequency and stimulus motion g. Perceptual learning is typically highly specific to the stimuli and task used during training.
Previous studies have shown that complex visual stimuli, such as emotional facial expressions, can influence brain activity independently of the observers awareness. Correlation of local and global orientation and spatial. It has previously been proposed that holistic face processing is based on low spatial frequencies sfs whereas featural processing relies on higher sfs, a hypothesis still widespread in the face processing literature today e. If we compare our result for the center spatial frequency of 1. In mathematics, physics, and engineering, spatial frequency is a characteristic of any structure that is periodic across position in space. The motion aftereffect mae was used to study the temporal and spatial frequency selectivity of the visual system at suprathreshold contrasts. In subthreshold summation studies the threshold for a spatial test pattern has. For any spatial and temporal adaptingfrequencies,the peak flickermaewas foundat lowcounterphasefrequencies. Spatial frequency tuning in human retinotopic visual areas jov. Any further analyses were performed using software developed inhouse. The stereoacuity versus spatial frequency function is a ushaped curve, with the optimum spatial frequency at approximately 7. The median halfheight width w 50 of isointensity tuning curves was 1. Oct 18, 2017 arousal has been shown to influence the spatial frequency tuning of cortical responses in mice mineault et al.
The dynamics of sf and orientation tuning and their interactions are of particular interest to neurophysiologists because they can reveal important information about the specific circuits and mechanisms of neuronal selectivity. Little is known yet, however, about the informational correlates of consciousness i. We carried out the first measurements of spatial frequency sf tuning for judgments of eye gaze, and compared sf tuning for judgments of facial identity and eye gaze. Spatial frequency bandwidth of surround suppression tuning curves. We measured spatial frequency sf tuning curves with functional magnetic.
Msf periods are too short to correct with deterministic figuring too long to ignore typically from 2 mm to about 0. The influence of natural contour and face size on the spatial. Pdf temporal and spatial frequency tuning of the flicker. Spatial ancestry analysis spa is a method for predicting ancestry or where an individual is from using the individuals dna. This tutorial explores the relationship between the distance separating these iris opening images and the periodic spacing. The results above demonstrate that spatial frequency tuning characteristics of the primary visual cortex change according to different visual topological locations of the cortical areas, in addition to the existence of spatial frequency columns. Spatial frequency tuning and transfer of perceptual learning for motion coherence reflects the tuning properties of global motion processing. Temporal and spatial frequency tuning of the flicker.
Spatialfrequency tuning halfwidth at halfheight for straight contours is. In both primates and cats, a shift of the neurons preferred spatial frequency has been observed. In a second experiment, we measured the spatial frequency tuning of flicker mae for low spatial frequencyadaptinggratings0. We found that lgn neurons exhibit inseparable spatiotemporal frequency tuning in a manner consistent with the feature of optimal filters that can maximize information transmission of natural scenes. Role of gabaergic inhibition in shaping the spatial. At each temporal frequency, there could be two or more peaks of response to different spatial frequencies, each distinct from the whole field flicker response. Stimuli were squarewave drifting gratings presented at 1. In several cases, tuning becomes more selective over the course of the response, and the preferred spatial frequency shifts from low to higher frequencies.
Difference of spatial frequency selectivity between static. We adapted a highspeed reversecorrelation method previously used to characterize orientation tuning dynamics in anesthetized animals. The human luminance spatial frequency contrast sensitivity function csf has been well studied using psychophysical measurements by detecting spatial frequency sf grating patterns at threshold. Observers adapted to drifting sinewave gratings of a range of spatial and temporal frequencies. Note, however, that the published spatial frequency tuning data 26 show inhibition for four data points only, so the gaussian curve fit has to be taken with some caution, and the analysis below. Spatial frequency tuning at two different spatial frequencies was determined by measuring the detectability of a signal grating that was made difficult to see by low or highpass visual noise. However, near threshold, the csf is measured at a linear area of the saturating. Broad tuning for spatial frequency is established first at the level of the. Dynamics of spatial frequency tuning in mouse visual cortex. Frontiers spatial frequency tuning during the conscious and. Spatial frequency and orientation tuning dynamics in area v1 james a.
However, recently it has been shown that training on global motion can transfer to untrained tasks, reflecting the generalising properties of mechanisms at this level of processing. Sep 09, 2009 first, we characterized the relationship between spatial and temporal frequency tuning for lgn receptive fields. The peak of the spatialfrequency tuning function was approximately 0. Osa spatialfrequency tuning as a function of temporal. The peak of the spatialfrequency tuning function was approximately cdeg. Threshold csfs at different eccentricities have proven to be quite useful in both basic and clinical vision research. The spatial frequency tuning curves also tended to have a smooth shift along the cortical surface. All data analyses were performed using builtin and custom software written in matlab mathworks.
Gamma frequency and the spatial tuning of primary visual cortex. The strength of motion aftereffect mae was measured with the use of sinusoidal gratings of several spatial frequencies, to examine the spatial frequency selectivity of two types of mae. Specifically, we measured spatial frequencytuning and directiontuning curves of each neuron in our fov by averaging across trials the response to each stimulus. It has been suggested that the early stages of human visual processing involve analysis by a parallel set of channels that may be defined in terms of their spatial and temporal tuning characteristics see graham 1989 for an overview. Nevertheless, we found the same asymmetry of the spatial frequency tuning of contralateral and ipsilateral responses in our anesthetized recordings as we did in our awake experiments. Difference of spatial frequency selectivity between static and flicker motion aftereffects. Specification and control of midspatial frequency wavefront e. Bruce henning david sarnoff research center, stanford research institute, princeton, new jersey 08540 received august 31, 1987. Dec 22, 2014 for assessment of frequency tuning, the response area was defined as the frequency range that elicited more than 50% of the maximum response. Since upright faces are supposedly recognized through holistic processing and inverted faces, using features. Pdf does face inversion change spatial frequency tuning. Such a conclusion would have significant conse quences for the way we think about spatial vision, tending to favor models that make explicit use of local.
The spatial frequency tuning of opticflowdependent behaviors in. The spatial frequency tuning of opticflowdependent behaviors in the bumblebee bombus impatiens jonathan p. Neurons in primate visual cortex are tuned for spatial frequency, and this tuning depends on eccentricity. Jan 29, 2002 spatial frequency sf and orientation tuning are two of the most prominent features of neuronal selectivity in primary visual cortex area v1. Spatial frequency tuning of the directional bias in checkerboard patterns. Spa was created by wenyun yang, john novembre, eleazar eskin and eran halperin. We adapted a highspeed reversecorrelation method previously used to characterize orientation tuning dynamics in anesthetized. Spatial frequency tuning of perceptual learning and. Spatial frequency and orientation tuning dynamics in area v1 pnas.
We measured the tuning of pyramidal cells in primary visual cortex by means of resonant, twophoton microcopy in alert, headfixed mice. Spatial frequency tuning characteristics of cat primary. Next, we tested the spatial frequency tuning of the centering response by lining the tunnel walls with sinusoidal narrowband patterns of different spatial frequencies. Neuronal spatial frequency tuning in primary visual cortex v1 substantially changes over time. Spatial frequency sf and orientation tuning are intrinsic properties of neurons in primary visual cortex area v1. Suprathreshold contrast matching functions also showed spatialfrequencydependent contrast loss for both notch.
Multiple spatialfrequency tuning of electrical responses. In a second experiment, we measured the spatial frequency tuning of flicker mae for low spatial frequency adapting gratings 0. Several studies have examined this dependency using fmri henriksson et al. Accurately modeling ancestry is an important step in identifying genetic variation involved in disease. Department of psychology, university of essex, wivenhoe park, colchester co4 3sq, uk. V1 neurons are tuned for orientation and spatial frequency. Spa a tool for analysis of spatial structure in genetic data. Contralateral bias of high spatial frequency tuning and. Pdf spatial frequency tuning of brightness polarity. Spatialfrequency and contrast tuning of the transient. Orientation tuning depends on spatial frequency in mouse. Whether the brightness is encoded by a large extraclassical receptive field or by a fillingin type mechanism activated by. Contrast masking reveals spatialfrequency channels in. The optimal frequency did not fall below 4 cdeg for checkerboard stimuli, which is still high for a motion phenomenon.
The results also suggest that the spatial frequency tuning of the process that produces local directional bias is bandpass shaped. We let the application determine the range of mid spatial frequency band since the msf band is defined by subtraction, there can be no single definition of the mid spatial frequency fabricationbased definition. Because the vanishing resolution measurement is the spatial frequency where image information disappears, it is strongly dependent on observer bias and is a poor indicator of image sharpness. We measured the tuning of pyramidal cells in primary visual cortex by means of resonant, two. When a line grating is imaged in the microscope, a series of conoscopic images representing the condenser iris opening can be seen at the objective rear focal plane. This is an interesting idea, as the aspect of segmentation has not been much attended in studies of the ouchi illusion. A higher order visual neuron tuned to the spatial amplitude. To study this transformation in spatial selectivity, we measured the dynamics of spatial frequency tuning using a reverse correlation. In part ii of the paper, we demonstrate that a simple feedforward model of spatial frequency prefer ence, unlike that for orientation preference, does not generate a faithful representation when ampli.
We investigated a if feedback was required for learning when using an equivalent noise global motion coherence task. The lower and upper edges of the frequency tuning curve were respectively the lowest and the highest frequencies of this range. Spatial frequency selectivity is a hallmark property of early visuocortical neurons, and mapping these sensitivities gives us crucial insight into. Dynamics of spatial frequency tuning in mouse visual cortex m ice are like high order visual based animals highly tuned to a narrow range of stimulus parameters, although they have much larger receptive fields and much lower visual acuity. Serrano pedraza, ignacio y grady, john p y read, jenny c a 2012 spatial frequency bandwidth of surround suppression tuning curves. Spatial frequency, phase, and the contrast of natural images.
The optimal frequency did not fall below 4 cdeg for checkerboard stimuli. The authors examined spatial frequency sf tuning of upright and inverted face identification using an sf variant of the bubbles technique f. Dynamics of spatial frequency tuning of macaque lgn request pdf. Spatial frequency tuning and transfer of perceptual. Spatial frequency tuning of the ouchi illusion and its. Comparison of the spatialfrequency selectivity of local and. At the lowest levels, motion signals are encoded locally within the relatively small receptive fields of v1 neurons 32,47. Spatial frequency tuning and transfer of perceptual learning. Does face inversion change spatial frequency tuning. The spatial frequency tuning of motion detectors differs according to the level of the visual hierarchy processing the sensory input, in a manner that is consistent with the generalising properties of higher level neurons. Spatial frequency tuning in the lateral geniculate nucleus of the thalamus lgn and primary visual cortex v1 differ substantially. A grating of high spatial frequency many cycles within each degree of visual angle contains narrow bars.
Using narrowband stimuli, we clearly showed that optical blur affects low frequency stimuli and high frequency stimuli. There is a shift in tuning to spatial frequency across different regions of the ventral occipital cortex. You may have seen test patterns like the one pictured right used to evaluate the fidelity of your printer or computer monitor. The usaf 1951 chart is poorly suited for computer analysis because it uses space inefficiently and its bar triplets lack a low frequency reference. The concept of spatial frequency is fundamental to all aspects of imaging, including photography, television, general radiology, as well as mri. Spatial frequency sf and orientation tuning are intrinsic properties of. Both doses of the drug affected the perg to the peak sf of the stimulus, but the higher one. Neurons within early visual cortex are selective for basic. Spatial frequency tuning of the monkey pattern erg depends.
Spatialfrequency tuning of visual contour integration. Spatial cue reliability drives frequency tuning in the barn. Baseline before sulpiride responses showed high intersession reproducibility, with a clear sf tuning. Spatial frequency and orientation tuning dynamics in area v1. Monocular blur alters the tuning characteristics of. To understand how gabaergic inhibition contributes to the elaboration of spatial frequency sf tuning of neurons in the lateral geniculate nucleus, we examined the effects of the microiontophoretic administration of bicuculline methiodide bic and gabazine, both antagonists of gaba a receptors, on visual responses to grating stimuli with high or low contrasts. Icx neurons showed broad frequency tuning, as has been previously reported konishi 2003. A third variable, spatial frequency tuning, has been found to be represented nonhomogeneously in striate cortex 10 15. Spatial frequency selectivity is well established and has been demonstrated both physiologically e. However, nasanen 1999, experiment 4 and ojanpaa and nasanen 2003 re. In experiment 1, participants discriminated between leftward and rightward shifts of gaze, or between two male faces or two female faces. This result is consistent with reverse hierarchy theory, in which learning operates through topdown guidance via reentrant connections. They obtained a tuning curve peaking at the center spatial frequency 1.
Osa spatialfrequency tuning of visual contour integration. Dynamics of spatial frequency tuning in macaque v1. Specifically, we measured spatial frequency tuning and direction tuning curves of each neuron in our fov by averaging across trials the response to each stimulus. Spatial frequency orientation masking introduction the spatial frequency tuning of human visual mech anisms has generally been estimated using one of two experimental paradigms. Frequency tuning curves in icx are broad and often lack an unequivocal peak. Spatial frequency shifts from counterphase flicker and. Mouse v1 neurons show tuning curves for orientation, spatial frequency, temporal frequency and contrast.
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