PURPOSE: Temporal modulation perimetry (TMP) is a new test procedure designed to measure sensitivity to sinusoidal flickering stimuli throughout the central 27 degrees visual field. The purpose of this investigation was to determine the effect of age and visual field eccentricity on temporal modulation sensitivity. METHOD: In its present form, ...

The detection of the direction of motion was measured as a function of the spatial and temporal offset for a kinematogram stimulus presented in two-frame apparent motion. The stimulus was made up of Gabor function micro-patterns randomly distributed across the stimulus field. We show that for short stimulus onset asynchronies ...

1. We studied the effects of midazolam (MDZ), a benzodiazepine, on spatio-temporal contrast sensitivity, choice reaction time, and mood visual analogue scales in healthy volunteers. 2. Eight extensively trained, healthy volunteers were included in a placebo-controlled cross-over double-blind trial of MDZ (0.15 mg kg-1). Treatments were injected intramuscularly and evaluations ...

When tested monocularly, strabismic and amblyopic subjects often show asymmetries of optokinetic nystagmus (OKN), with OKN being more readily elicited by temporal-to-nasal than by nasal-to-temporal stimulus motion. We tested five visually normal subjects and ten strabismic and/or amblyopic subjects by use of motion-nulling stimuli, which consisted of superimposed temporal-to-nasal and ...

The ear contains an array of filters that separate the components of a complex signal into "channels" tuned to different center frequencies. Temporal analysis can be considered as two processes: analysis of the time pattern occurring within each channel, and comparison of the time patterns across channels. Within-channel acuity can ...

Temporal and spatial aspects of sensory interactions during human fusional response were investigated using band-limited, 10th-derivative-of-Gaussian patterns confined to separate regions of the visual field. Experiments were performed to investigate the time course of sensory interactions using the horizontal sensory fusional amplitude (SFA) and the sensory fusional range (SFR) as ...

A bi-local detector array model was assumed to describe the functional performance of monocular motion perception. Distributions of model parameters were measured in human vision at several positions in the visual field. The stimulus paradigm was designed to measure directional motion perception thresholds for individual combinations of spatial displacement and ...

In a series of recent reports, Simmons and his colleagues propose that bats are able to accurately encode the spectral, temporal and phase information of their emitted calls and echoes. The information so encoded is then extracted by the networks of the auditory system with specialized processing. They propose that ...

The electric organ discharge (EOD) potential was mapped on the skin and midplane of several Apteronotus leptorhynchus. The frequency components of the EOD on the surface of the fish have extremely stable amplitude and phase. However, the waveform varies considerably with different positions on the body surface. Peaks and zero ...

1. Optimal spatiotemporal filters for early vision were computed as a function of signal-to-noise ratio (SNR) and alpha, a parameter defined as the ratio of the width of the probability distribution of velocities as perceived by the naturally behaving animal, and the characteristic velocity of the photoreceptors (the velocity required ...

Numerosity discrimination was examined when items were varied in space-time position rather than in space only. Observers were instructed to indicate which of two adjacent streams of visual events contained more items. The precision of numerosity discrimination of dynamic events was not remarkably different from that of static patterns. Two ...

A technique that compensates for low spatial frequency spurious phase changes during an interference experiment is developed; it permits temporal averaging of multiple phase measurements, made before and after object displacement. The method is tested with phase-stepped real-time holographic interferometry applied to cantilever bending of a piezoelectric bimorph ceramic. Results ...

The ability of listeners to detect asynchrony in either the temporal onset or offset of individual components in a multicomponent complex was investigated. A standard stimulus was created having a simple kind of asynchrony by linearly delaying successive components of a complex stimulus. Additional asynchrony (the signal) was created by ...

A technique that compensates for low spatial frequency spurious phase changes during an interference experiment is developed; it permits temporal averaging of multiple phase measurements, made before and after object displacement. The method is tested with phase-stepped real-time holographic interferometry applied to cantilever bending of a piezoelectric bimorph ceramic. Results ...

Electrical stimulation of the human auditory system produces different patterns of spatial and temporal neural activity than those that occur in the normal, acoustically stimulated system. Quantitative comparison of psychophysical performance measured with acoustic and electrical stimulation may allow us to infer the physiological locus of perceptual mechanisms. In this ...

Perceived temporal frequency is vastly underestimated in the peripheral visual field, as all temporal frequencies above 10 Hz are perceived as flickering at 10 Hz even after scaling for acuity. Varying the contrast and spatial frequency of the peripheral pattern four-fold have negligible effects on the perceived flicker rate. Speed ...

The focal electroretinogram (FERG) was used to examine temporal frequency tuning at the outer retinal level in humans by measuring temporal modulation thresholds. Changes in FERG thresholds as a function of ambient light level were compared to temporal modulation thresholds obtained psychophysically using the same stimuli. At lower temporal frequencies, ...

When observers view the relative movements of a pair of bars defined by the difference of spatial Gaussian functions (DOGs), they can accurately discriminate coherent movements over a range of temporal frequencies and temporal asynchronies. Of particular interest is the fact that performance accuracy is maintained even when the two ...

The COSS analysis [B. G. Berg, J. Acoust. Soc. Am. 86, 1743-1746 (1989)] was used to estimate spectral and temporal weights of a three-component, amplitude-modulated stimulus in a spectral-shape discrimination task. In all experiments, the task of the observer was to detect an increment in the level of the center ...

A difference equation model was developed to explore the sensitivity of the temporal pattern of relative abundance of active, host-seeking nymphal Ixodes dammini. Inputs to the model were the temporal patterns of recruitment of nymphs into the active class, mortality and successful acquisition of hosts by the ticks. Input parameters ...

The postnatal development of the temporal properties of the responses to pattern contrast reversal has been studied by recording simultaneously the pattern electroretinogram (PERG) and visual evoked potentials (PVEP) in infants 3-22 weeks old. The stimulus grating (0.5 c/deg) was either reversed in contrast sinusoidally at frequencies 4-10.5 Hz to ...

A previous study showed that roughness perception may depend on either temporal or spatial variations in firing rate among cutaneous mechanoreceptive afferents. The present study was designed to distinguish between these hypotheses. Plastic surfaces embossed with patterns of dots designed to produce predictable alterations in temporal and spatial firing rate ...

The ability of 3-month-old human infants to detect the presence of spatial misalignments in single-bar stimuli was investigated in a series of spatiotemporal stimulus manipulations. Both discrete and sinusoidal positional offsets, either stationary or temporally modulated, were presented using the forced-choice preferential looking technique. When discrete offsets were presented in ...

The Lukosz technique of superresolution by spatial and temporal frequency interaction is extended. The effects of various misalignments and other errors are considered. An implementation of the technique is presented. Experimental results are given.

We have recorded patterns electroretinograms (PERGs) and visual evoked potentials (VEPs) from 14 elderly subjects (mean age 72 yr) and 12 young subjects (mean age 21 yr) in response to stimulation by high contrast sinusoidal grating patterns of variable spatial frequency (at 9 Hz) and temporal frequency (at 1.7 c/deg). ...

We asked the question "is the visual field temporally homogeneous when the well known spatial inhomogeneity is taken into account?" Our results show that the visual field exhibits inhomogeneity for stimuli of low spatial frequency for which the spatial inhomogeneity is minimal. This inhomogeneity takes the form of a reduction ...

Uniform field temporal contrast sensitivity functions were compared for 10 subjects with congenital nystagmus (seven idiopathic, three with albinism) and 10 normal observers. Sensitivity to luminance modulation did not differ significantly from normal at any temporal frequency tested except 0.5 Hz, at which the subjects with nystagmus had slightly higher ...

The application of the transformation technique of Stork and Falk [J. Opt. Soc. Am. A 4, 1130 (1987)] to the temporal contrast sensitivity functions of patients and normal subjects brings out several pitfalls that resulted from their choices for low- and high-frequency extrapolation. Other choices, more closely reflecting the known ...

We used static perimetry to measure the development of the monocular visual field during infancy. Infants from birth to 6 months of age, and adults, were shown a 3 or 6 degrees flashing light at various locations between 15 and 120 degrees in the temporal and nasal visual fields. We ...

The temporal phase of the pattern reversal VEP has been investigated using stimulation with laser interference fringes in Maxwellian view. VEP phase was almost constant as function of spatial frequency (2-30 c/deg, 6.5 r/sec, 51 subjects). The phase function however shows a small phase increase at low spatial frequencies consistent ...

The initial filtering of the image by the human visual system involves only a small number of temporal filters. Several studies suggest there are in fact only two, but some suggest that a third filter, sensitive to high frequencies, exists, at least at low spatial frequencies. This conclusion is derived ...

The temporal properties of the foveal visual filters were revealed using a method which is a variant on previously used noise masking paradigms. This enables the temporal properties of the mechanisms underlying threshold detection of a spatio-temporal probe to be measured. In accord with recent suggestions these results support the ...

Structural, petrological, and geochronological studies of the middle to late Proterozoic Grenville orogen in Ontario, Canada, indicate that a major extensional fault developed synchronously with late thrusting. This fault zone was initiated during peak metamorphism and extended into the crust to depths of at least 25 kilometers. The temporal and ...

Considerations derived from the fields of physics, philosophy, anthropology, and psychology suggest that our popular conception of time as a unidirectional and uniform flow may not be an adequate description of the human experience of time. Indeed, other dimensions of temporality may constitute important aspects of human phenomenology with respect ...

A well-studied subject with visual cortex damage (G.Y.) was tested in his hemianopic field with temporally modulated sinusoidal and square-wave gratings. The purpose was to use an extended range of parameters to obtain a detailed spatiotemporal specification of his residual vision and to try to resolve the discrepancy between negative ...

Earlier work has established that oscillatory movement displacement thresholds (OMDT) are a form of hyperacuity. There is speculation that the mechanism determining OMDT, like motion perception in general, involves direct motion sensing at high temporal frequencies of oscillation and spatial localization processes (from which motion is inferred) at low temporal ...

McKee, Silverman and Nakayama (1986; Vision Research, 26, 609-619) have shown that velocity discrimination performance is little affected by quite large random changes in the spatial frequency, and hence temporal frequency, of the grating patterns to be discriminated. We show that the converse is also true: temporal frequency discrimination can ...

To study how adaptation to spatial frequency patterns affects temporal sensitivity in vision, observers were selectively adapted for 4 min to either a high- or a low-spatial-frequency sinusoidal grating (12 and 2 cpd, respectively). Their sensitivities to modulation of a blurred patch at high or low temporal frequencies (12 Hz ...

Temporal sensitivity was assessed in patients with primary open-angle glaucoma (POAG) and ocular hypertension (OHT). Three measures of flicker sensitivity were obtained: psychophysical modulation thresholds, visual-evoked potentials (VEPs), and focal electroretinograms (FERGs). We found elevated psychophysical thresholds at higher temporal frequencies (30-50 Hz) in patients with POAG, relative to thresholds ...

The hippocampus has been proposed to participate in either spatial or temporal mapping. As an alternative to these seemingly conflicting views, we hypothesized that the hippocampus computes 'aggregate predictions' of environmental events that are used to control associative learning. Aggregate predictions forecast what event is going to occur, when in ...

The auditory temporal integration function was studied with the objective of improving both its quantitative description and the specification of its principle independent variable, stimulus duration. In Sec. I, temporal integration data from 20 studies were subjected to uniform analyses using standardized definitions of duration and two models of temporal ...

A theory is developed that integrates approaches to the analysis of pathway transient response and metabolic control analysis. A Temporal Control Coefficient is defined that is a measure of the system's transient response to modulation of enzyme activity or concentration. The approach allows for the analysis of the establishment of ...

The strength of the flanking inhibitory regions of the receptive fields of fly lamina cells (LMC) decreases as the mean luminance is lowered. Simultaneously, the biphasic temporal flash (impulse) response of the lamina cells becomes monophasic on lowering luminance. For a moving-edge stimulus at high mean luminance, this implies that ...

In an earlier article [Moore et al., J. Acoust. Soc. Am. 83, 1102-1116 (1988)], preliminary work on the temporal-window model of temporal resolution in the auditory system was described. The temporal window is conceived of as a temporal integrator that slides in time and that is implemented as an intensity-weighting ...

The development of temporal integration was investigated in young chickens who momentarily delay their ongoing peeps when they hear a sound. An adaptive procedure was used to estimate absolute thresholds of pure tones and bands of noise between 10 and 460 ms in duration. Over 400 animals were tested at ...

The basic hypothesis of the author is that under the influence of technological development and market pressure, situations take on temporal characteristics that are more and more difficult for the operator to control. The temporal strategies traditionally installed by the operator disappear, are transferred or transformed. Far from counterbalancing these ...

The behaviour of Dictyostelium discoideum amoebae has been studied in natural cAMP waves and in controlled spatial and temporal gradients. Chemoattractant gradients induce responses which indicate that amoebae spatially compare concentration increases at different points on the cell surface. This allows them to respond to the relative spatial and temporal ...

Temporal modulation sensitivity functions were measured centrally and at eccentricities of 2.5 degrees, 5 degrees and 10 degrees in the temporal visual field of 12 patients with recovered optic neuritis and in a group of matched normal controls. A circular, spatially uniform stimulus of 1 degree angular subtense was presented ...

Chromatic, spatial, and temporal losses of sensitivity were measured in 15 eyes of 10 patients with recovered optic neuritis. Chromatic sensitivities (for both red-green and blue-yellow) were measured using color-mixture thresholds; the chromatic sensitivity loss was classified as "selective" if it was significantly greater than the achromatic loss. Spatial and ...

Visual information travels from the retina to visual cortical areas along at least two parallel pathways. In this paper, anatomical and physiological evidence is presented to demonstrate the existence of, and trace these two pathways throughout the visual systems of the cat, primate, and human. Physiological and behavioral experiments are ...