A method for estimating intrinsic noise in electroretinographic (ERG) signals

Zele, Andrew J.; Feigl, Beatrix; Kambhampati, Pradeep Kumar; Hathibelagal, Amithavikram R.; Kremers, Jan

doi:10.1007/s10633-015-9510-1

Cited by 7 publications

(6 citation statements)

References 24 publications

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“…For the pupil measurements, each trial was separated by a 1 ms blank interval (46) and the trial repeated 10 times during a single recording sequence that was repeated at least 10 times (~100 trials per observer per stimulus condition; 8 conditions X 2 stimulus durations = ~1,600 total trials per observer). Testing sessions were <1.5 h to avoid the effect of observer fatigue and sleepiness on pupil responses.…”

Section: Methodsmentioning

confidence: 99%

Melanopsin and Cone Photoreceptor Inputs to the Afferent Pupil Light Response

Zele¹,

Adhikari²,

Cao³

et al. 2019

Front. Neurol.

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Background: Retinal photoreceptors provide the main stage in the mammalian eye for regulating the retinal illumination through changes in pupil diameter, with a small population of melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) forming the primary afferent pathway for this response. The purpose of this study is to determine how melanopsin interacts with the three cone photoreceptor classes in the human eye to modulate the light-adapted pupil response. Methods: We investigated the independent and combined contributions of the inner and outer retinal photoreceptor inputs to the afferent pupil pathway in participants with trichromatic color vision using a method to independently control the excitations of ipRGCs, cones and rods in the retina. Results: We show that melanopsin-directed stimuli cause a transient pupil constriction generated by cones in the shadow of retinal blood vessels; desensitizing these penumbral cone signals uncovers a signature melanopsin pupil response that includes a longer latency (292 ms) and slower time (4.1x) and velocity (7.7x) to constriction than for cone-directed stimuli, and which remains sustained post-stimulus offset. Compared to melanopsin-mediated pupil responses, the cone photoreceptor-initiated pupil responses are more transient with faster constriction latencies, higher velocities and a secondary constriction at light offset. The combined pupil responses reveal that melanopsin signals are additive with the cone signals. Conclusions: The visual system uses the L–, M–, and S–cone photoreceptor inputs to the afferent pupil pathway to accomplish the tonic modulations of pupil size to changes in image contrast. The inner retinal melanopsin-expressing ipRGCs mediate the longer-term, sustained pupil constriction to set the light-adapted pupil diameter during extended light exposures.

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Section: Methodsmentioning

confidence: 99%

Melanopsin and Cone Photoreceptor Inputs to the Afferent Pupil Light Response

Zele¹,

Adhikari²,

Cao³

et al. 2019

Front. Neurol.

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“…The Maxwellian view stimulator in Brisbane was based on a custom-built one-channel optical system. 18 The systems in Bradford and Erlangen used Ganzfeld bowls presented in Newtonian view (in Erlangen: Q450SC; Roland Consult, Brandenburg, Germany; in Bradford: Espion; Diagnosys, Cambridge, UK). All stimuli were produced with narrow-band light-emitting diodes.…”

Section: Methodsmentioning

confidence: 99%

“…The ERG recording procedures have been described in detail elsewhere. 18 – 20 Similar recording settings were used in all laboratories. Briefly, continuous ERGs were recorded from one eye in all participants with an active fiber electrode placed across the lower conjunctiva and attached near the inner and outer canthi according to International Society for Clinical Electrophysiology of Vision (ISCEV) standards.…”

Section: Methodsmentioning

confidence: 99%

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A Temporal White Noise Analysis for Extracting the Impulse Response Function of the Human Electroretinogram

Zele

Feigl

Kambhampati

et al. 2017

Trans. Vis. Sci. Tech.

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PurposeWe introduce a method for determining the impulse response function (IRF) of the ERG derived from responses to temporal white noise (TWN) stimuli.MethodsThis white noise ERG (wnERG) was recorded in participants with normal trichromatic vision to full-field (Ganzfeld) and 39.3° diameter focal stimuli at mesopic and photopic mean luminances and at different TWN contrasts. The IRF was obtained by cross-correlating the TWN stimulus with the wnERG.ResultsWe show that wnERG recordings are highly repeatable, with good signal-to-noise ratio, and do not lead to blink artifacts. The wnERG resembles a flash ERG waveform with an initial negativity (N1) followed by a positivity (P1), with amplitudes that are linearly related to stimulus contrast. These N1 and N1-P1 components showed commonalties in implicit times with the a- and b-waves of flash ERGs. There was a clear transition from rod- to cone-driven wnERGs at ∼1 photopic cd.m−2. We infer that oscillatory potentials found with the flash ERG, but not the wnERG, may reflect retinal nonlinearities due to the compression of energy into a short time period during a stimulus flash.ConclusionThe wnERG provides a new approach to study the physiology of the retina using a stimulation method with adaptation and contrast conditions similar to natural scenes to allow for independent variation of stimulus strength and mean luminance, which is not possible with the conventional flash ERG.Translational RelevanceThe white noise ERG methodology will be of benefit for clinical studies and animal models in the evaluation of hypotheses related to cellular redundancy to understand the effects of disease on specific visual pathways.

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“…Random variations in neural activity that occur independent of the stimulus signal are termed intrinsic noise [1,2]. These intrinsic noise levels are similar for magnocellular (MC) and parvocellular (PC) retinal ganglion cells and independent of stimulus contrast as observed in single-cell recordings of macaque retinae [3] and in human electroretinography [4]. Any variation present in the stimulus domain, including that introduced by quantal fluctuation [5,6], is termed extrinsic noise.…”

Section: Introductionmentioning

confidence: 99%

Correlated and uncorrelated invisible temporal white noise alters mesopic rod signaling

et al. 2016

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We determined how rod signaling at mesopic light levels is altered by extrinsic temporal white noise that is correlated or uncorrelated with the activity of one (magnocellular, parvocellular, or koniocellular) postreceptoral pathway. Rod and cone photoreceptor excitations were independently controlled using a four-primary photostimulator. Psychometric (Weibull) functions were measured for incremental rod pulses (50 to 250 ms) in the presence (or absence; control) of perceptually invisible subthreshold extrinsic noise. Uncorrelated (rod) noise facilitates rod detection. Correlated postreceptoral pathway noise produces differential changes in rod detection thresholds and decreases the slope of the psychometric functions. We demonstrate that invisible extrinsic noise changes rod-signaling characteristics within the three retinogeniculate pathways at mesopic illumination depending on the temporal profile of the rod stimulus and the extrinsic noise type.

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A method for estimating intrinsic noise in electroretinographic (ERG) signals

Cited by 7 publications

References 24 publications

Melanopsin and Cone Photoreceptor Inputs to the Afferent Pupil Light Response

Melanopsin and Cone Photoreceptor Inputs to the Afferent Pupil Light Response

A Temporal White Noise Analysis for Extracting the Impulse Response Function of the Human Electroretinogram

Correlated and uncorrelated invisible temporal white noise alters mesopic rod signaling

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