Relation between psychophysics and electrophysiology of flicker

Tweel, L. H. van der

doi:10.1007/bf00160581

Cited by 43 publications

(29 citation statements)

References 12 publications

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“…Previous studies have shown sensitivity of phasic ganglion cells to luminance flicker in macaque that is comparable to results obtained from humans using psychophysical threshold measurements [18]. In humans, two studies found CFF/ERG to be higher than psychophysical CFF [19,20], however the reverse has been reported in dog [21]. Both psychophysical [22] and ERG electrophysiological [23] measurements display a prominent rod/cone break, indicating the relationship between CFF and stimulus intensity.…”

Section: Introductionsupporting

confidence: 71%

Flicker assessment of rod and cone function in a model of retinal degeneration

Rubin

Kraft

2007

Doc Ophthalmol

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Critical flicker frequency (CFF) is the lowest frequency for which a flickering light is indistinguishable from a non-flickering light of the same mean luminance. CFF is related to light intensity, with cone photoreceptors capable of achieving higher CFF than rods. A contemporaneous measure of rod and cone function can facilitate characterization of a retinal degeneration. We used sinusoidal flicker ERG to obtain CFF values, over a wide range of light intensities, in RCS dystrophic (RCS-p(+)) and wild type rats. Recordings were made at PN23, PN44, and PN64. The CFF curve in control animals increased in proportion to the log of stimulus intensity, with a gentle slope over the lowest 4 log-unit intensity range. The slope of the CFF curve dramatically increased for higher intensities, indicating a rod-cone break. In the RCS rats the rod driven CFF was significantly lower in amplitude compared to normal rats at the earliest age tested (PN23). By PN64 the rod driven CFF was immeasurable in the RCS rats. The amplitude of the cone driven CFF approached normal values at PN23, but was greatly reduced by PN44. By PN64 the entire CFF function was greatly depressed and there was no longer a discernable rod-cone break. These CFF/ERG data show that RCS rats exhibit significant early degeneration of the rods, followed soon after by degeneration of the cones. Using this approach, rod and cone function can be independently accessed using flicker ERG by testing at a few select intensities.

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Section: Introductionsupporting

confidence: 71%

Flicker assessment of rod and cone function in a model of retinal degeneration

Rubin

Kraft

2007

Doc Ophthalmol

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“…With the noninvasive EEG technology, it seems impossible at present to identify the alpha-wave-and visually evoked potential-generating structures beyond the level worked out by Makeig et al (2002). Sometimes brain waves have been considered a mere consequence of linear processing, such as band-pass filtering or linear oscillation (van der Tweel 1964;Spekreijse 1966;Lopes da Silva et al 1974). More recently, a resetting of the phase of alpha waves by visual stimuli was described (Brandt 1997;Makeig et al 2002).…”

Section: Relationship To Results In the Literaturementioning

confidence: 97%

“…Usually brain waves are considered to be due to self-sustained oscillators which are necessarily nonlinear. Sometimes brain waves have been interpreted as a mere consequence of linear processing, such as bandpass filtering or linear oscillations (van der Tweel 1964;Spekreijse 1966;Lopes da Silva et al 1974). Linear and nonlinear contributions in brain waves were also demonstrated (Gebber et al 1999;Stam et al 1999).…”

Section: Linear Systems and Nonlinear Oscillatorsmentioning

confidence: 94%

The physical basis of alpha waves in the electroencephalogram and the origin of the ?Berger effect?

Kirschfeld

2005

Biol Cybern

117

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Synchronised activity, differing in phase in different populations of neurons, plays an important role in existing theories on the function of brain oscillations (e.g., temporal correlation hypothesis). A prerequisite for this synchronisation is that stimuli are capable of affecting (resetting) the phase of brain oscillations. Such a change in the phase of brain waves is also assumed to underlie the "Berger effect": when observers open their eyes, the amplitude of EEG oscillations in the alpha band (8-13 Hz) decreases significantly. This finding is usually thought to involve a desynchronisation of activity in different neurons. For functional interpretations of brain oscillations in the visual system, it therefore seems to be crucial to find out whether or not the phase of brain oscillations can be affected by visual stimuli. To answer this question, we investigated whether alpha waves are generated by a linear or a nonlinear mechanism. If the mechanism is linear - in contrast to nonlinear ones - phases cannot be reset by a stimulus. It is shown that alpha-wave activity in the EEG comprises both linear and nonlinear components. The generation of alpha waves basically is a linear process and flash-evoked potentials are superimposed on ongoing alpha waves without resetting their phase. One nonlinear component is due to light adaptation, which contributes to the Berger effect. The results call into question theories about brain-wave function based on temporal correlation or event-related desynchronisation.

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“…3 and 4 show that ambient flicker at imperceptibly high frequencies can penetrate to the neural site for flicker adaptation, which is presumed to be in primary visual cortex (23). Indeed, earlier physiological studies have demonstrated activity in human visual cortex in response to imperceptibly high flicker frequencies (5,6), but these studies suggested no impact on perception as a result of this cortical activity. Our present findings show a clear, deleterious impact of this visuocortical response, as elicited by invisible flicker, on our ability to see subsequent perturbations in luminance or chromaticity.…”

Section: Discussionmentioning

confidence: 95%

“…The modulation transfer function (MTF) for human flicker perception, which traces modulation sensitivity as a function of flicker frequency, peaks around 8 Hz (4 Hz for chromatic flicker) and falls precipitously, by Ͼ100-fold, with increasing flicker frequency, out to the resolution limit (1)(2)(3)(4). The neural processing that mediates this sharply low-pass nature of the MTF for flicker perception remains little understood (5)(6)(7)(8)(9). Specifically, the questions of what the number and anatomical loci of the neural filtering stages involved are remain open.…”

mentioning

confidence: 99%

Adaptation from invisible flicker

Shady

MacLeod

Fisher

2004

Proc. Natl. Acad. Sci. U.S.A.

102

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Human ability to resolve temporal variation, or flicker, in the luminance (brightness) or chromaticity (color) of an image declines with increasing frequency and is limited, within the central visual field, to a critical flicker frequency of Ϸ50 and 25 Hz, respectively. Much remains unknown about the neural filtering that underlies this frequency-dependent attenuation of flicker sensitivity, most notably the number of filtering stages involved and their neural loci. Here we use the process of flicker adaptation, by which an observer's flicker sensitivity is attenuated after prolonged exposure to flickering lights, as a functional landmark. We show that flicker adaptation is more sensitive to high temporal frequencies than is conscious perception and that prolonged exposure to invisible flicker of either luminance or chromaticity, at frequencies above the respective critical flicker frequency, can compromise our visual sensitivity. This suggests that multiple filtering stages, distributed across retinal and cortical loci that straddle the locus for flicker adaptation, are involved in the neural filtering of high temporal frequencies by the human visual system.

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Relation between psychophysics and electrophysiology of flicker

Cited by 43 publications

References 12 publications

Flicker assessment of rod and cone function in a model of retinal degeneration

Flicker assessment of rod and cone function in a model of retinal degeneration

The physical basis of alpha waves in the electroencephalogram and the origin of the ?Berger effect?

Adaptation from invisible flicker

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