Heritable functional architecture in human visual cortex

Curation statements for this article:
  • Curated by eLife

    eLife logo

    Evaluation Summary:

    The paper was viewed as generally sound. There main concern was that the findings were viewed as incremental without a demonstration of a link between the heritability of pRF properties and visual perception. The speculation in the Discussion about shared perceptual experience is intriguing, but psychophysical (or other) evidence would be needed to really make that point clearly. In addition, there was some discussion about the non-independence of vertices and correlation values. In the end, we all agreed that non-independent vertices may inflate correlation coefficient values, but that this is unlikely to substantially affect conclusions drawn from comparisons of monozygotic and dizygotic twins.

    (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 agreed to share their name with the authors.)

This article has been Reviewed by the following groups

Read the full article See related articles

Abstract

How much of the functional organization of our visual system is inherited? Here we tested the heritability of retinotopic maps in human visual cortex using functional magnetic resonance imaging. We demonstrate that retinotopic organization shows a closer correspondence in monozygotic (MZ) compared to dizygotic (DZ) twin pairs, suggesting a partial genetic determination. Using population receptive field (pRF) analysis to examine the preferred spatial location and selectivity of these neuronal populations, we estimate a heritability around 30% for polar angle preferences and spatial selectivity, as quantified by pRF size, in extrastriate areas V2 and V3. Our findings are consistent with heritability in both the macroscopic arrangement of visual regions and stimulus tuning properties of visual cortex. This could constitute a neural substrate for variations in a range of perceptual effects, which themselves have been found to be at least partially genetically determined. These findings also add convergent evidence for the hypothesis that functional map topology is linked with cortical morphology.

Highlights

  • We analyzed retinotopic maps from monozygotic and dizygotic twin pairs

  • Visual field maps in V1-V3 are more similar in monozygotic twins

  • Heritability is greater in V1 and V3 for polar angle and population receptive field sizes

  • Eccentricity maps show lesser degree of heritability

  • Further evidence for link between cortical morphology and topology of retinotopic maps

Graphical Abstract

Article activity feed

  1. Reviewer #2 (Public Review):

    Alvarez et al. present a study of the heritability of functional properties of early visual cortex, as assessed by a population receptive field (pRF) analysis of retinotopic mapping data in monozygotic (MZ) versus dizygotic (DZ) twin pairs. The use of a MZ versus DZ twin design is a strength, as it permits estimates of heritability, and connects the retinotopic mapping and pRF literature to the literature examining heritability of a diverse range of cognitive functions.

    I have only one point of concern that I feel the authors should address. It seems that the correlation analysis assumes that each vertex in the cortical surface model represents an independent observation, but an assumption of independence does not appear to be satisfied. FMRI responses in nearby vertices are expected to be highly inter-dependent, as a single fMRI voxel may be mapped onto many vertices. Spatial blurring intrinsic to the fMRI signal (i.e., point-spread function), as well as the spatial smoothing of pRF parameters that was performed, would be expected to exacerbate this issue.

  2. Reviewer #1 (Public Review):

    The authors employed population receptive field (pRF) mapping to characterize responses to visual stimuli in early visual cortical areas V1-V3 and to compare the similarity of pRF properties in pairs of monozygotic versus dizygotic twins. They find closer correspondence of the anatomical location and spatial extent of the visual areas, pRF locations (polar angle and eccentricity) in the retinotopic cortical maps of visual space, and spatial selectivity of responses (pRFs size) in monozygotic twins, relative to dizygotic twins, indicating heritability of these structural and functional properties of early visual cortex.

    The pRF mapping procedures used in this study are appropriate and standard in the field, and the statistical analysis and data presentation are thorough and rigorous. Given the many previous demonstrations of heritability in multiple aspects of visual perception and physiological responses to visual stimuli, it would be very surprising if any of the properties studied by the authors did not exhibit some amount of heritability. This paper therefore adds to the list of known heritable properties of the visual system but does not contribute theoretical or conceptual advances or challenge any existing frameworks.

    The fact that pRF eccentricity was more correlated and showed less heritability than pRF polar angle is interesting but was not interpreted or followed up in any meaningful way. Overall, the analyses are basic (% overlap of retinotopic maps and the three main pRF parameters) and descriptive.

  3. Evaluation Summary:

    The paper was viewed as generally sound. There main concern was that the findings were viewed as incremental without a demonstration of a link between the heritability of pRF properties and visual perception. The speculation in the Discussion about shared perceptual experience is intriguing, but psychophysical (or other) evidence would be needed to really make that point clearly. In addition, there was some discussion about the non-independence of vertices and correlation values. In the end, we all agreed that non-independent vertices may inflate correlation coefficient values, but that this is unlikely to substantially affect conclusions drawn from comparisons of monozygotic and dizygotic twins.

    (This preprint has been reviewed by eLife. We include the public reviews from the reviewers here; the authors also receive private feedback with suggested changes to the manuscript. Reviewer #1 agreed to share their name with the authors.)