PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

Martin, Joel T; Pinto, Joana; Bulte, Daniel P.; Spitschan, Manuel

doi:10.3758/s13428-021-01759-3

Cited by 9 publications

(5 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To present synchronised stimulus modulations independently to each eye, two light engines (Spec-traTuneLAB: LEDMOTIVE Technologies, LLC, Barcelona, Spain), each with 10 independently addressable LED colour channels, were integrated into a customised viewing system. The light engines were operated via a Python interface to their REST API (39), which supports synchronous launch and playback of spectral sequences prepared in advance and stored in JSON format. When preparing the spectral sequences, the age of participants was used to account for the yellowing of the lenses.…”

Section: Apparatus and Stimulimentioning

confidence: 99%

Binocular combination in the autonomic nervous system

Segala,

Bruno,

Martin

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

1AbstractThe diameter of the pupil fluctuates in response to levels of ambient light and is regulated by the autonomic nervous system. Increasing light in one eye causes both pupils to constrict, implying the system must combine signals across the two eyes – a process of binocular integration occurring independently of visual cortex. Distinct classes of retinal photoreceptor are involved in controlling and maintaining pupil diameter, with cones and rods driving the initial constriction and intrinsically photosensitive retinal ganglion cells maintaining diameter over prolonged time periods. Here, we investigate binocular combination by targeting different photoreceptor pathways using the silent substitution method to modulate the input spectra. We find different patterns of binocular response in each pathway, and across the first and second harmonic frequencies. At the first harmonic, luminance and S-cone responses showed strong binocular facilitation, and weak interocular suppression. Melanopsin responses were invariant to the number of eyes stimulated. Notably, the L-M pathway involved binocular inhibition, whereby responses to binocular stimulation were weaker than for monocular stimulation. The second harmonic involved strong interocular suppression in all pathways, but with some evidence of binocular facilitation. Our results are consistent with a computational model of binocular signal combination (implemented in a Bayesian hierarchical framework), in which the weight of interocular suppression differs across pathways. We also find pathway differences in response phase, consistent with different lag times for phototransduction. This work demonstrates for the first time the algorithm governing binocular combination in the autonomic nervous system.

show abstract

Section: Apparatus and Stimulimentioning

confidence: 99%

Binocular combination in the autonomic nervous system

Segala,

Bruno,

Martin

et al. 2024

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…We conducted a conceptual replication of Experiment 1 using an alternative system of hardware and software (Martin et al, 2023(Martin et al, , 2022. A pair of Spectra Tune Lab multiprimary devices (LEDmotive Technologies LLC, Barcelona, Spain) were coupled to a binocular headset using liquid light guides.…”

Section: Author Contributionsmentioning

confidence: 99%

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways

Segala

Bruno

Aung

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

How does the brain combine information across the eyes? In primary visual cortex, spatial patterns are subject to "ocularity invariance", where monocular and binocular responses are rendered equal by mutual suppression between the eyes. Here we asked whether this invariance holds for pure changes in luminance. We collected steady-state EEG and pupillometry data simultaneously, and find strong deviations from ocularity invariance both in the cortex and also in the subcortical pathway that determines pupil diameter. In cortex, we find strong binocular facilitation, and negligible interocular suppression from cortical sources, whereas measurements of pupil diameter showed weaker facilitation and stronger suppression. This was not purely a consequence of the temporal stimulus parameters; pronounced binocular facilitation was also observed at faster flicker rates. Near-linear binocular combination was also found for the same stimuli using a perceptual matching task. A hierarchical Bayesian implementation of a standard binocular combination model confirms that interocular suppression was substantially weaker for our EEG and matching data compared with the pupillometry results. These findings illustrate that ocularity invariance is not a ubiquitous feature of visual processing, and that the brain can repurpose a generic algorithm for different functions by adjusting parameters such as the weight of suppression between pathways.

show abstract

“…We conducted a conceptual replication of Experiment 1 using an alternative system of hardware and software ( Martin et al, 2023 ; Martin et al, 2022 ). A pair of Spectra Tune Lab multiprimary devices (LEDmotive Technologies LLC, Barcelona, Spain) were coupled to a binocular headset using liquid light guides.…”

Section: Appendix 1—figurementioning

confidence: 99%

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways

Segala

Bruno

Aung

et al. 2023

eLife

Self Cite

View full text Add to dashboard Cite

How does the human brain combine information across the eyes? It has been known for many years that cortical normalisation mechanisms implement ‘ocularity invariance’: equalising neural responses to spatial patterns presented either monocularly or binocularly. Here we used a novel combination of electrophysiology, psychophysics, pupillometry and computational modelling to ask whether this invariance also holds for flickering luminance stimuli with no spatial contrast. We find dramatic violations of ocularity invariance for these stimuli, both in cortex and also in the subcortical pathways that govern pupil diameter. Specifically, we find substantial binocular facilitation in both pathways with the effect being strongest in cortex. Near-linear binocular additivity (instead of ocularity invariance) was also found using a perceptual luminance matching task. Ocularity invariance is therefore not a ubiquitous feature of visual processing, and the brain appears to repurpose a generic normalisation algorithm for different visual functions by adjusting the amount of interocular suppression.

show abstract

PyPlr: A versatile, integrated system of hardware and software for researching the human pupillary light reflex

Cited by 9 publications

References 62 publications

Binocular combination in the autonomic nervous system

Binocular combination in the autonomic nervous system

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways

Different rules for binocular combination of luminance flicker in cortical and subcortical pathways

Contact Info

Product

Resources

About