# Population Dynamics in the Oculomotor System

> **NIH NIH R01** · UNIVERSITY OF PITTSBURGH AT PITTSBURGH · 2021 · $370,387

## Abstract

PROJECT SUMMARY
Sensorimotor transformations are mediated by premotor brain networks where individual neurons represent
sensory, cognitive, and movement-related information. In the superior colliculus (SC), a central hub for
producing visually-guided saccadic eye movements, many neurons are active during all three stages, emitting
transient, high-frequency bursts of spikes during the sensory and motor events and exhibiting persistent, lower
firing rate activity in-between the bursts. The mixed-selectivity to multiple dimensions of information exemplifies
a potentially efficient mode of information representation by the nervous system, but it also raises crucial
questions: What features differentiate the two bursts, and how does a decoder know precisely when to initiate
a movement if its inputs are active at times when a movement is not desired (e.g., in response to sensory
stimulation)? What information is encoded in the low-frequency activity, and how is it modulated during
different cognitive demands? We reason that the answers to these questions lie not in the activity of individual
neurons but rather across the population of active neurons and in the temporal dynamics. Specific Aim 1 tests
various neural mechanisms of movement initiation by quantifying features that differentiate the sensory and
motor bursts across the SC population. Specific Aim 2 focuses on the low-frequency activity that intervenes
between the two bursts. We will use a dynamical systems approach to characterize how the neural trajectory
evolves during sensorimotor transformation and how it differs for tasks with different cognitive loads. The ability
to discriminate neural trajectories according to task demands indicates a potential mechanism by which
different dimensions of information can be multiplexed into the same population of neurons.

## Key facts

- **NIH application ID:** 10135085
- **Project number:** 5R01EY024831-06
- **Recipient organization:** UNIVERSITY OF PITTSBURGH AT PITTSBURGH
- **Principal Investigator:** Neeraj J Gandhi
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $370,387
- **Award type:** 5
- **Project period:** 2015-01-01 → 2024-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10135085

## Citation

> US National Institutes of Health, RePORTER application 10135085, Population Dynamics in the Oculomotor System (5R01EY024831-06). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10135085. Licensed CC0.

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