The influence of retinal illuminance on L- and M-cone driven electroretinograms

Kremers, Jan; Parry, Neil R. A.; Panorgias, Athanasios; Murray, Ian J.

doi:10.1017/s0952523810000556

Cited by 8 publications

(3 citation statements)

References 28 publications

(44 reference statements)

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“…Although colour vision is normal in his case, I.J.M. is known to have an unusually high proportion of long‐wavelength cones (see Kremers et al 2011) and it is therefore unsurprising that his isoluminant red:green ratio is shifted towards green (RGR = 0.4). As would be expected, the dichromats also show a displaced isoluminant value (0.35 for the deuteranope, 0.8 for the protanope), indicating the need for a higher than normal proportion of one colour to balance the other.…”

Section: Resultsmentioning

confidence: 94%

Simultaneous chromatic and luminance human electroretinogram responses

Parry

Murray

Panorgias

et al. 2012

The Journal of Physiology

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Key points• It has recently been shown that, with careful control over stimulation, the electroretinogram (ERG) can reflect the properties of the post-receptoral parvocellular (P) and magnocellular (M) pathways, which are thought of as the respective substrates for red-green colour and luminance vision.• Using a novel compound stimulus, which contains red-green colour information at the fundamental frequency and luminance information at the second harmonic, we were able to simultaneously record colour and luminance ERGs.• In trichromats, the temporal tuning curves of these components reflected the known properties of the P and M systems, whereas the dichromats showed negligible chromatic response but a normal achromatic response.• Parallel retinal processing that is relevant for vision can be reflected in the ERG.Abstract The parallel processing of information forms an important organisational principle of the primate visual system. Here we describe experiments which use a novel chromatic-achromatic temporal compound stimulus to simultaneously identify colour and luminance specific signals in the human electroretinogram (ERG). Luminance and chromatic components are separated in the stimulus; the luminance modulation has twice the temporal frequency of the chromatic modulation. ERGs were recorded from four trichromatic and two dichromatic subjects (1 deuteranope and 1 protanope). At isoluminance, the fundamental (first harmonic) response was elicited by the chromatic component in the stimulus. The trichromatic ERGs possessed low-pass temporal tuning characteristics, reflecting the activity of parvocellular post-receptoral mechanisms. There was very little first harmonic response in the dichromats' ERGs. The second harmonic response was elicited by the luminance modulation in the compound stimulus and showed, in all subjects, band-pass temporal tuning characteristic of magnocellular activity. Thus it is possible to concurrently elicit ERG responses from the human retina which reflect processing in both chromatic and luminance pathways. As well as providing a clear demonstration of the parallel nature of chromatic and luminance processing in the human retina, the differences that exist between ERGs from trichromatic and dichromatic subjects point to the existence of

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Section: Resultsmentioning

confidence: 94%

Simultaneous chromatic and luminance human electroretinogram responses

Parry

Murray

Panorgias

et al. 2012

The Journal of Physiology

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“…The comparison of the responses to the cone isolating stimuli with each other and with the conditions in which the two are modulated simultaneously reveals a few interesting features. In previous measurements, using modulation at high temporal frequency, it was found that the L-cone driven responses are generally larger than the M-cone driven responses reflecting the larger number of L-cones (Brainard et al, 2000; Kremers, Parry, Panorgias & Murray, 2011; Kremers et al, 2000). However, in Figures 4 and 5 it can be seen that the response amplitudes in the asymmetries to L-and M-cone stimuli are similar when the cone contrasts are similar.…”

Section: Discussionmentioning

confidence: 92%

Asymmetries in the contributions of On- and Off-mechanisms to the ERG signal.

Kremers¹

2013

Psychology & Neuroscience

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ERG responses were recorded to rapid-on and rapid-off L-and M-cone isolating sawtooth stimuli of different cone contrasts. In addition, the responses were recorded to simultaneous in-phase stimulation of the L-and M-cones at equal cone contrast. Linear responses to mirror imaged rapid-on and rapid-off sawtooth stimuli are also mirror imaged. By adding on-and offresponses, linear response components will cancel and nonlinearities will remain. Because nonlinearities that occur at a certain stage of visual processing will influence subsequent stages, linear response components will probably have an outer retinal origin and nonlinearities probably originate mainly in the inner (post-receptoral) retina.

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“…In a number of studies there have been attempts to identify and isolate long-(L), middle-(M), and short-(S) wavelength-sensitive cone mechanisms within the ERG response [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27]. In many of these experiments, cone isolation was usually achieved either by chromatic adaptation [18] or silent substitution [25] methods.…”

Section: Introductionmentioning

confidence: 99%

Incremental and decremental L- and M-cone-driven ERG responses: I Square-wave pulse stimulation

et al. 2014

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Electroretinograms (ERGs) elicited by transient, square-wave L- and M-cone isolating stimuli were recorded from human trichromatic (n=19) and dichromatic (n=4) observers. The stimuli were generated on a four primary LED stimulator and were equated in terms of cone modulation (cone contrast=0.11) and retinal illuminance (12,000 trolands). L- and M-cone isolated ERGs had waveforms similar to those observed for luminance responses. However, M-cone ERGs exhibited a phase reversal in their responses to onset and offset stimuli relative to the L-cone responses. This on-off response reversal was observed in trichromats but not dichromats. Simultaneous counterphase and inphase combinations of L- and M-cone isolating stimuli generated responses that reflected chromatic and luminance processing, respectively. We conclude that L- and M-cone specific ERGs provide a measure of how photoreceptors contribute to postreceptoral mechanisms.

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The influence of retinal illuminance on L- and M-cone driven electroretinograms

Cited by 8 publications

References 28 publications

Simultaneous chromatic and luminance human electroretinogram responses

Simultaneous chromatic and luminance human electroretinogram responses

Asymmetries in the contributions of On- and Off-mechanisms to the ERG signal.

Incremental and decremental L- and M-cone-driven ERG responses: I Square-wave pulse stimulation

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