Physiological basis of resolution acuity in vision.
Level 5 - mechanism / opinion, no new human data
Non-human animal (macaque) neurophysiology study.
PubMed 41654559 · doi:10.1038/s41467-026-68851-0
What was done
Researchers mapped parafoveal lateral geniculate nucleus (LGN) receptive fields in male macaques using an adaptive optics microstimulator to stimulate individual cones and align receptive fields to the underlying retinal cone mosaic. Findings were evaluated alongside biophysical light capture modeling and spatial frequency tuning data.
What was found
The abstract reports no numerical values. It found that parvocellular LGN receptive field centres were most often driven by signals from a single cone photoreceptor, confirming that early primate visual pathways operate at the theoretical resolution limit set by cone spacing.
Why it matters
This provides direct physiological evidence resolving a long-standing question in vision science, confirming that primate visual resolution is preserved at the single-cone level prior to cortical processing.
Limits
The study was conducted in male macaques rather than humans. The abstract does not specify the sample size (number of animals or mapped neurons) or report quantitative effect sizes and variance measures.