Optical stimulation systems for studying human vision

BARRIONUEVO, PABLO A.; PRECIADO, OSCAR U.; SANDOVAL, MARÍA L.; ISSOLIO, LUIS A.

Circadian and Visual Neuroscience

Elsevier

Año: 2022;

In this chapter, we described the most common set-ups that scientists use for generating light stimulation, from lab-made approaches to commercially available technologies. We divided the studied optical stimulation systems into non-image-forming and image-forming Arrangements. Among the first, we described two classical systems widely used: the Maxwellian View System and the Ganzfeld Stimulator. Between the Image-forming Arrangements, we focused on approaches that consider off-the-shelf devices and we highlighted the recent appearance of Multi-primary Displays, which allow the inclusion of more primaries and let to generate stimulation for independent and combined photoreceptor and postreceptoral excitations. Then, we centered on some of the several limitations that can have important implications in research practice, such as those related to color gamut, sampling frequency, light range, and spatial resolution. Since experimentation for studying how optical radiation is processed by the human neural system requires to assure the reliability of the parameters and variables under study, the characterization and the consequent calibration of experimental devices are essential. Therefore, we mentioned a set of characterization and calibration principles that researchers should consider when carrying out experiments with the described optical stimulators. Outstanding characteristics are stimulator response curve, primaries? spectral power distribution, additivity, modulation transfer function, and temporal stability. Finally, we indicated some possible sources of artifacts that the researcher should consider when these stimulators are used. Throughout this last section, we provided data based on different optical stimulators measurements.