# Neural correlates of 3D visual orientation

> **NIH NIH R01** · NEW YORK UNIVERSITY · 2020 · $396,250

## Abstract

ABSTRACT
We can see things in three dimensions (3D) because the visual system reconstructs the 3D configuration of
objects from their two-dimensional images projected onto the retina. Previous studies have described loss of
3D binocular vision and constructional apraxia after parietal lesions, although the neurophysiology of this effect
remains poorly understood. Furthermore, many studies have characterized the neural basis of binocular
disparity processing, although few have dealt with the representation of 3D object orientation and how this is
maintained invariant in the world. In the proposed studies we will examine neural selectivity for 3D planar
orientation in the caudal intraparietal area (CIP), visual posterior sylvian (VPS) and area V3A of macaque
monkeys. We employ a multi-faceted approach, combining neural recordings, behavior, population decoding
and chemical inactivation. We will directly test the role of each of these areas in slant discrimination by first
recording and then manipulating neural activity while macaques perform a fine slant discrimination task. Neural
firing rates will be analyzed using signal detection theory and we will quantify neuronal variability by measuring
noise correlations and choice probabilities. We will also probe for causal links between neurons in these areas
and slant orientation perception by employing reversible inactivation. Furthermore, it has been known that
gravity plays a critical role in shaping our visual experience of the world, influencing both sensory perception
and motor planning, but surprisingly little is known about where and how the brain may use a neural estimate
of gravity to transform visual signals from retinal to an allocentric representation. The proposed experiments
will test the hypothesis that the transformation occurs progressively, beginning with an egocentric
representation in V3A (CIP's main visual input) and culminating in a primarily gravity-centered representation:
V3A (egocentric)  CIP  VPS (mostly gravity-centered). Finally, we will test earth-vertical slant orientation
perception in animals after bilateral labyrinthectomy to monitor deficits in visual orientation perception, both
acutely and after recovery from peripheral vestibular lesion. We hypothesize acute deficits, but also a
functional recovery as the role of proprioceptive signals increases. This research is important for understanding
multisensory visual–vestibular influences on 3D vision in a 3D world.

## Key facts

- **NIH application ID:** 9942477
- **Project number:** 5R01EY022538-07
- **Recipient organization:** NEW YORK UNIVERSITY
- **Principal Investigator:** Dora Angelaki
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $396,250
- **Award type:** 5
- **Project period:** 2013-02-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9942477

## Citation

> US National Institutes of Health, RePORTER application 9942477, Neural correlates of 3D visual orientation (5R01EY022538-07). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9942477. Licensed CC0.

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