# Unveiling the computations underlying behavioral heterogeneity across and around the visual field

> **NIH NIH F31** · NEW YORK UNIVERSITY · 2024 · $34,305

## Abstract

PROJECT SUMMARY
Visual performance (e.g., contrast sensitivity) varies as a function of eccentricity and polar angle: Performance
worsens as eccentricity increases and is better along the horizontal than the vertical meridian (horizontal-vertical
anisotropy, HVA) and along the lower- than upper-vertical meridian (vertical meridian asymmetry, VMA) at a
fixed eccentricity. Contrast sensitivity and the extent of performance heterogeneity correlate with surface area in
early occipital areas. A quantitative account relates the better performance at the fovea than peripheral locations
to more cones and larger V1 cortical surface area, but does not suffice to explain polar angle asymmetries. A
qualitative account posits that performance differences relate to differential system-level computations
throughout the visual field, including efficiency –the ability to extract signal information, the amount of internal
noise, and tuning –sensitivity to and selectivity for signal features. Here, we test the main hypothesis that
performance differences throughout the visual field are attributed to both quantitatively varying surface area and
qualitatively distinct representations and computations. We capitalize on the fact that presenting signals in noise
enables quantifying internal noise and observers’ ability to extract and represent task-relevant information: We
estimate efficiency and internal noise using the equivalent noise method (Aim1), and derive the perceptual
representation of task-relevant features using psychophysical reverse correlation (Aim2&3). To link the
quantitative and qualitative accounts, we examine whether the observed difference in performance and
perceptual representation can be matched across locations by equating the V1 surface area encoding the stimuli
for each individual observer (Aim3). Preliminary data suggest that distinct representations and computations
underlie the performance heterogeneity throughout the visual field. Whereas the eccentricity effect may be due
to lower internal noise at the fovea than perifovea (Aim1), both HVA and VMA may reflect a higher efficiency
(Aim1) and better representation of task-relevant orientations (Aim2) at the horizontal than vertical meridian and
at the lower- than upper-vertical meridian, whereas HVA and VMA may reflect differential SF-related
computations (Aim2). We further evaluate whether differences in neural correlates go beyond the V1 surface
area of each individual observer. We hypothesize that matching the V1 cortical area dedicated to processing the
stimuli would eliminate the eccentricity effect, but at most reduce polar angle asymmetries (Aim3). By identifying
the computations involved in basic visual tasks across eccentricity and polar angle, results will shed light on how
the early visual cortex integrates neural resources to give rise to visual performance. Further, knowledge of the
computations underlying varying performance across locations could have translational value for o...

## Key facts

- **NIH application ID:** 10996867
- **Project number:** 1F31EY036732-01
- **Recipient organization:** NEW YORK UNIVERSITY
- **Principal Investigator:** Shutian Xue
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $34,305
- **Award type:** 1
- **Project period:** 2024-09-01 → 2027-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10996867

## Citation

> US National Institutes of Health, RePORTER application 10996867, Unveiling the computations underlying behavioral heterogeneity across and around the visual field (1F31EY036732-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10996867. Licensed CC0.

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