Organisation and Interrelationships of Functional Maps in Cat and Monkey Striate Cortex

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 356-356
Author(s):  
D Shoham ◽  
M Hübener ◽  
T Bonhoeffer ◽  
A Grinvald
Keyword(s):  
Spatial Frequency ◽  
Cytochrome Oxidase ◽  
Striate Cortex ◽  
Temporal Frequency ◽  
Activity Patterns ◽  
Ocular Dominance ◽  
High Spatial Frequency ◽  
Spatial Frequencies ◽  
Frequency Domains

Optical imaging of intrinsic signals allows mapping of the cortical functional architecture in vivo at high spatial resolution. The ability to image activity patterns evoked by many different stimuli in the same piece of cortex can provide information on the spatial relationships between different functional maps. Our findings on the organisation of multiple functional maps in cat and monkey striate cortex are reviewed. The main focus is on the recent finding in cat of two subsystems differing in their response to spatiotemporal aspects of the stimulus. We used grating stimuli of different spatial frequencies in an attempt to verify the existence of spatial frequency columns in cat area 17. Rather than observing a map of continuously changing spatial frequency across the cortical surface we found two distinct sets of domains, one preferring low and one preferring high spatial frequencies. By using different drift velocities we also found that the low-spatial-frequency domains preferred higher speeds than the high-spatial-frequency domains. Comparison of these spatiotemporal frequency domains with the cytochrome oxidase staining pattern revealed that the cytochrome oxidase blobs in cat striate cortex coincide with domains devoted to the processing of the low-spatial-frequency and high-temporal-frequency contents of the visual scene. Together with recent anatomical results these data suggest that spatiotemporal frequency domains are the manifestation of parallel streams in cat visual cortex with distinct patterns of thalamic inputs and extrastriate projections. In the same experiments we also imaged the orientation preference and ocular dominance maps. We investigated the relationships between these three columnar systems, and compared them to an earlier study of orientation, ocular dominance, and blobs in macaque striate cortex. We found systematic relationships between the three systems. While some of these relationships were much weaker than those found in monkey, the organisational principles are similar.

scholarly journals Neuronal basis of perceptual learning in striate cortex

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Zhen Ren ◽  
Jiawei Zhou ◽  
Zhimo Yao ◽  
Zhengchun Wang ◽  
Nini Yuan ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Perceptual Learning ◽  
Contrast Sensitivity ◽  
Striate Cortex ◽  
Signal To Noise Ratio ◽  
High Spatial Frequency ◽  
Sensitivity Training ◽  
Spatial Frequencies ◽  
Cortex Area ◽  
Adult Cats

Abstract It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells’ optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

Role of the color-opponent and broad-band channels in vision

1990 ◽  
Vol 5 (04) ◽  
pp. 321-346 ◽  
Author(s):  
Peter H. Schiller ◽  
Nikos K. Logothetis ◽  
Eliot R. Charles
Keyword(s):  
Spatial Frequency ◽  
Temporal Frequency ◽  
Broad Band ◽  
High Spatial Frequency ◽  
Brightness Perception ◽  
Rods And Cones ◽  
Form Vision ◽  
Temporal Domain ◽  
Frequency Domains

AbstractThe functions of the primate color-opponent and broad-band channels were assessed by examining the visual capacities of rhesus monkeys following selective lesions of parvocellular and magnocellular lateral geniculate nucleus, which respectively relay these two channels to the cortex. Parvocellular lesions impaired color vision, high spatial-frequency form vision, and fine stereopsis. Magnocellular lesions impaired high temporal- frequency flicker and motion perception but produced no deficits in stereopsis. Low spatial-frequency form vision, stereopsis, and brightness perception were unaffected by either lesion. Much as the rods and cones of the retina can be thought of as extending the range of vision in the intensity domain, we propose that the color-opponent channel extends visual capacities in the wavelength and spatial-frequency domains whereas the broad-band channel extends them in the temporal domain.

Effect of repetitive visual stimuli on behaviour and plasma corticosterone of European starlings

2005 ◽  
Vol 55 (3) ◽  
pp. 245-258 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Spatial Frequency ◽  
High Frequency ◽  
Temporal Frequency ◽  
Low Frequency ◽  
High Spatial Frequency ◽  
Plasma Corticosterone ◽  
European Starlings ◽  
Fluorescent Lamps ◽  
Spatial Frequencies ◽  
Temporal And Spatial

AbstractFlickering light can cause adverse effects in some humans, as can rhythmic spatial patterns of particular frequencies. We investigated whether birds react to the temporal frequency of standard 100 Hz fluorescent lamps and the spatial frequency of the visual surround in the manner predicted by the human literature, by examining their effects on the preferences, behaviour and plasma corticosterone of European starlings (Sturnus vulgaris). We predicted that high frequency lighting (> 30 kHz) and a relatively low spatial frequency on the walls of their cages (0.1 cycle cm−1) would be less aversive than low frequency lighting (100 Hz) and a relatively high spatial frequency (2.5 cycle cm−1). Birds had strong preferences for both temporal and spatial frequencies. These preferences did not always fit with predictions, although there was evidence that 100 Hz was more stressful than 30 kHz lighting, as birds were less active and basal corticosterone levels were higher under 100 Hz lighting. Our chosen spatial frequencies had no overall significant effect on corticosterone levels. Although there are clearly effects of, and interactions between, the frequency of the light and the visual surround on the behaviour and physiology of birds, the pattern of results is not straightforward.

Harmonic basis functions for spatial coding in the cat striate cortex

1989 ◽  
Vol 3 (4) ◽  
pp. 351-363 ◽  
Author(s):  
V. D. Glezer ◽  
V. V. Yakovlev ◽  
V. E. Gauzelman
Keyword(s):  
Spatial Frequency ◽  
Striate Cortex ◽  
Weighting Function ◽  
Discrete Distribution ◽  
Basis Functions ◽  
Spatial Coding ◽  
Central Visual Field ◽  
Spatial Frequencies ◽  
The Absolute ◽  
Number Of Cycles

AbstractThe number of subregions in the activity profiles of simple cells varies in different cells from 2–8; that is, the number of cycles in the weighting function varies from 1–4. The distribution of receptive-field (RF) sizes at eccentricities of 0-6 deg are clustered at half-octave intervals and form a discrete distribution with maxima at 0.62, 0.9, 1.24, 1.8, 2.48, and 3.4 deg. The spatial frequencies to which the cells are tuned are also clustered at half-octave intervals, forming a discrete distribution peaking at 0.45, 0.69, 0.9, 1.35, 1.88, 2.7, 3.8, and 5.6 cycles/deg. If we divide the RF sizes by the size of the period of the subregions, then the average indices of complexity (really existing) or the number of cycles in the weighting function form (after normalization) the sequences: 1, 1.41, 2.0, 2.9, 4.15.The relation between the bandwidth of the spatial-frequency characteristic and the optimal spatial frequency is in accordance with predictions of the Fourier hypothesis. The absolute bandwidth does not change with the number of cycles/module. This means that inside the module the absolute bandwidth does not change with the number of the harmonic. The results allow us to suggest the following. A module of the striate cortex, which is a group of cells with RFs of equal size projected onto the same area of central visual field, accounts for the Fourier description of the image. The basis functions of the module are composed of four harmonics only, irrespective of size and position of the module.Besides linear cells (sinusoidal and cosinusoidal elements), the module contains nonlinear cells, performing a nonlinear summation of the responses of sinusoidal and cosinusoidal elements. Such cells are characterized by an index of complexity which is more than the number of cycles in the weighting function and by marked overlap of ON and OFF zones. The analysis of organization suggests that the cells can measure the amplitude and phase of the stimulus.

scholarly journals Contrast thresholds reveal different visual masking functions in humans and praying mantises

2017 ◽  
Author(s):  
Ghaith Tarawneh ◽  
Vivek Nityananda ◽  
Ronny Rosner ◽  
Steven Errington ◽  
William Herbert ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Motion Detection ◽  
Visual Masking ◽  
High Spatial Frequency ◽  
Visual Noise ◽  
Frequency Noise ◽  
Detection Systems ◽  
Spatial Frequencies ◽  
Summary Statement ◽  
Contrast Thresholds

AbstractRecently, we showed a novel property of the Hassenstein-Reichardt detector: namely, that insect motion detection can be masked by “invisible” noise, i.e. visual noise presented at spatial frequencies to which the animals do not respond when presented as a signal. While this study compared the effect of noise on human and insect motion perception, it used different ways of quantifying masking in two species. This was because the human studies measured contrast thresholds, which were too time-consuming to acquire in the insect given the large number of stimulus parameters examined. Here, we run longer experiments in which we obtained contrast thresholds at just two signal and two noise frequencies. We examine the increase in threshold produced by noise at either the same frequency as the signal, or a different frequency. We do this in both humans and praying mantises (Sphodromantis lineola), enabling us to compare these species directly in the same paradigm. Our results confirm our earlier finding: whereas in humans, visual noise masks much more effectively when presented at the signal spatial frequency, in insects, noise is roughly equivalently effective whether presented at the same frequency or a lower frequency. In both species, visual noise presented at a higher spatial frequency is a less effective mask.Summary StatementWe here show that despite having similar motion detection systems, insects and humans differ in the effect of low and high spatial frequency noise on their contrast thresholds.

Natural scenes have matched amplitude-modulated sounds that systematically influence visual scanning

2012 ◽  
Vol 25 (0) ◽  
pp. 121
Author(s):  
Marcia Grabowecky ◽  
Aleksandra Sherman ◽  
Satoru Suzuki
Keyword(s):  
Eye Movements ◽  
Spatial Frequency ◽  
Memory Task ◽  
High Spatial Frequency ◽  
Visual Object ◽  
Natural Scenes ◽  
Scale Invariant ◽  
Visual Coding ◽  
Visual Spatial ◽  
Spatial Frequencies

We have previously demonstrated a linear perceptual relationship between auditory amplitude-modulation (AM) rate and visual spatial-frequency using gabors as the visual stimuli. Can this frequency-based auditory–visual association influence perception of natural scenes? Participants consistently matched specific auditory AM rates to diverse visual scenes (nature, urban, and indoor). A correlation analysis indicated that higher subjective density ratings were associated with faster AM-rate matches. Furthermore, both the density ratings and AM-rate matches were relatively scale invariant, suggesting that the underlying crossmodal association is between visual coding of object-based density and auditory coding of AM rate. Based on these results, we hypothesized that concurrently presented fast (7 Hz) or slow (2 Hz) AM-rates might influence how visual attention is allocated to dense or sparse regions within a scene. We tested this hypothesis by monitoring eye movements while participants examined scenes for a subsequent memory task. To determine whether fast or slow sounds guided eye movements to specific spatial frequencies, we computed the maximum contrast energy at each fixation across 12 spatial frequency bands ranging from 0.06–10.16 cycles/degree. We found that the fast sound significantly guided eye movements toward regions of high spatial frequency, whereas the slow sound guided eye movements away from regions of high spatial frequency. This suggests that faster sounds may promote a local scene scanning strategy, acting as a ‘filter’ to individuate objects within dense regions. Our results suggest that auditory AM rate and visual object density are crossmodally associated, and that this association can modulate visual inspection of scenes.

Temporal and Spatial Frequency Tuning of the Flicker Motion Aftereffect

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 12-12
Author(s):  
P J Bex ◽  
F A J Verstraten ◽  
I Mareschal
Keyword(s):  
Spatial Frequency ◽  
Frequency Tuning ◽  
Temporal Frequency ◽  
Motion Aftereffect ◽  
Sine Wave ◽  
Test Grating ◽  
Spatial Frequency Tuning ◽  
Spatial Frequencies ◽  
Low Pass ◽  
Sine Wave Gratings

The motion aftereffect (MAE) was used to study the temporal-frequency and spatial-frequency selectivity of the visual system at suprathreshold contrasts. Observers adapted to drifting sine-wave gratings of a range of spatial and temporal frequencies. The magnitude of the MAE induced by the adaptation was measured with counterphasing test gratings of a variety of spatial and temporal frequencies. Independently of the spatial or temporal frequency of the adapting grating, the largest MAE was found with slowly counterphasing test gratings (∼0.125 – 0.25 Hz). For slowly counterphasing test gratings (<∼2 Hz), the largest MAEs were found when the test grating was of similar spatial frequency to that of the adapting grating, even at very low spatial frequencies (0.125 cycle deg−1). However, such narrow spatial frequency tuning was lost when the temporal frequency of the test grating was increased. The data suggest that MAEs are dominated by a single, low-pass temporal-frequency mechanism and by a series of band-pass spatial-frequency mechanisms at low temporal frequencies. At higher test temporal frequencies, the loss of spatial-frequency tuning implicates separate mechanisms with broader spatial frequency tuning.

scholarly journals Spatial Frequency Response of Epoxy-Based Volume Holographic Recording Material

Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1018
Author(s):  
Tina Sabel
Keyword(s):  
Spatial Frequency ◽  
Frequency Response ◽  
High Spatial Frequency ◽  
Holographic Recording ◽  
Holographic Gratings ◽  
Mass Migration ◽  
Spatial Frequencies ◽  
Recording Material ◽  
Wide Range ◽  
Transmission And Reflection

Holographic volume phase gratings are recorded in an epoxy-based, free-surface, volume holographic recording material. Light-induced gratings are formed by photo-triggered mass migration caused by component diffusion. The material resolution enables a wide range of pattern spacings, to record both transmission and reflection holograms with many different spatial frequencies. An optimum spatial frequency response is found between the low spatial frequency roll-off and the high spatial frequency cut-off. The influence of the energy density of exposure on the spatial frequency response is investigated. Secondary volume holographic gratings (parasitic gratings) are observed in the high frequency range. The possibility of distinguishing the regular grating from the secondary grating is discussed in the form of probe wavelength detuning.

Role of suppression in shaping orientation and direction selectivity of complex neurons in cat striate cortex

1996 ◽  
Vol 75 (3) ◽  
pp. 1163-1176 ◽  
Author(s):  
P. Hammond ◽  
J. N. Kim
Keyword(s):  
Spatial Frequency ◽  
Striate Cortex ◽  
Cutoff Frequency ◽  
Direction Selectivity ◽  
Uniform Field ◽  
Directional Tuning ◽  
Tuning Curves ◽  
Spatial Frequencies ◽  
Dominant Eye ◽  
Cat Striate Cortex

1. Single binocularly driven complex neurons in cat striate cortex were recorded extracellularly under nitrous oxide-oxygen-halothane anesthesia and muscle relaxant. Orientational/directional tuning was initially derived for each eye in turn, with sine wave gratings of optimal spatial frequency and velocity, while the other eye viewed a uniform field. 2. For the dominant eye, previously concealed suppression was revealed against elevated levels of firing induced with a conditioning grating, drifting continuously in the preferred direction, simultaneously presented to the nondominant eye. During steady-state binocular conditioning, orientational/directional tuning was reestablished for the dominant eye. In a subset of cells, tuning curves during conditioning were also derived for the reverse configuration, i.e., nondominant eye tuning, dominant eye conditioning: results were qualitatively identical to those for conditioning through the nondominant eye. 3. Neurons were initially segregated into five groups, according to the observed suppression profiles induced at nonoptimal orientations/directions during conditioning: Type 1, suppression centered on orthogonal directions; Type 2, suppression around null directions; Type 3, null suppression combined with orthogonal suppression; Type 4, lateral suppression, maximal for directions immediately flanking those inducing excitation; and Type 5, the residue of cells, totally lacking suppression or showing complex or variable suppression. 4. Sharpness of (excitatory) tuning was correlated with directionality and with class of suppression revealed during binocular conditioning. Direction-biased neurons were more sharply orientation tuned than direction-selective neurons; similarly, neurons exhibiting lateral or orthogonal suppression during conditioning were more sharply tuned than neurons with null suppression. 5. Application of suboptimal directions of conditioning weakened the induced suppression but altered none of its main characteristics. 6. The relationship between excitation, suppression, and spatial frequency was investigated by comparing tuning curves for the dominant eye at several spatial frequencies, without and during conditioning. End-stopped neurons preferred lower spatial frequencies and higher velocities of motion than non-end-stopped neurons. Confirming previous reports, suppression in some neurons was still present for spatial frequencies above the cutoff frequency for excitation, demonstrating the tendency for suppression to be more broadly spatial frequency tuned than excitation. 7. Scatterplots of strength of suppression, in directions orthogonal and opposite maximal excitation, partially segregated neurons of Types 1-3. Clearer segregation of Types 1-4 was obtained by curve-fitting to profiles of suppression, and correlating half-width of tuning for suppression with the angle between the directions of optimal suppression and optimal excitation in each neuron. 8. Two interpretations are advanced-the first, based on three discrete classes of inhibition, orthogonal, null and lateral; the second, based on only two classes, orthogonal and null/lateral--in which null and lateral suppression are manifestations of the same inhibitory mechanism operating, respectively, on broadly tuned direction-selective or on sharply tuned direction-biased neurons. Orthogonal suppression may be untuned for direction, whereas lateral and null suppression are broadly direction tuned. Within each class, suppression is more broadly spatial frequency tuned than excitation. 9. It is concluded that orientational/directional selectivity of complex cells at different spatial frequencies is determined by the balance between tuned excitation and varying combinations of relatively broadly distributed or untuned inhibition.

Envelope-responsive neurons in areas 17 and 18 of cat

1994 ◽  
Vol 72 (5) ◽  
pp. 2134-2150 ◽  
Author(s):  
Y. X. Zhou ◽  
C. L. Baker
Keyword(s):  
Spatial Frequency ◽  
Cortical Neurons ◽  
Narrow Range ◽  
High Spatial Frequency ◽  
Sine Wave ◽  
Relative Strength ◽  
Visual Responses ◽  
Spatial Frequencies ◽  
Sensitivity Level ◽  
Areas 17 And 18

1. Single cortical neurons are known to respond to visual stimuli containing Fourier components only in a narrow range of spatial frequencies. This investigation demonstrates that some neurons in cat area 17 and 18 can also respond to certain stimuli that have no Fourier components inside the cell's luminance spatial frequency passband. 2. To study such “non-Fourier” responses, we used envelope stimuli that consisted of a high-spatial-frequency sinusoidal luminance grating (carrier) whose contrast was modulated by a low-spatial frequency sine wave (envelope). There was no Fourier component at the apparent periodicity of the envelope spatial frequency. However, some cells responded to such a “phantom” component of the envelope modulation when it fell inside the cell's luminance spatial frequency passband while all the real Fourier components in the stimuli were outside. 3. We conducted extensive control experiments to eliminate the possibility of producing artifactual responses to the envelope stimuli due to any small residual nonlinearity of the z-linearized CRT screen. The control experiments included 1) testing of screen linearity to ensure that the effect from the residual screen nonlinearity was no larger than the sensitivity level of visual responses and 2) comparing the responses to envelope stimuli with the responses to the equivalent contrast of the artifact produced by the screen nonlinearity. All these control experiments indicated that any effect of screen nonlinearity did not contribute significantly to the neural envelope responses. 4. We performed a statistical analysis to obtain an index of relative strength of envelope responses for each cell and to objectively classify cells as “envelope-responsive” or “non-envelope-responsive.”(ABSTRACT TRUNCATED AT 250 WORDS)

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