# Spatiotemporal patterns of neural activity and their role in perception

> **NIH NIH R01** · SALK INSTITUTE FOR BIOLOGICAL STUDIES · 2024 · $459,020

## Abstract

PROJECT SUMMARY
Individual neurons within the visual cortex exhibit variable responses when repeatedly presented with the same
stimulus, and these fluctuations predict whether or not a faint target will be detected. In the prior round of funding,
this team discovered that “intrinsic traveling waves” (iTWs) occur spontaneously in visual area MT of the awake
marmoset. Previous studies had observed iTWs, but since the animals were anesthetized, it remained unknown
(1) if iTWs occur in awake animals and (2) what role, if any, iTWs play in perception. The team found that iTWs
create periods of both elevated and suppressed spiking activity. They also found that iTWs conjointly modulate
both stimulus-evoked spiking responses and perceptual sensitivity in a visual detection task. A large-scale
spiking network model developed by the team predicts that iTWs are a result of the time delays from axonal
conduction along the long-range horizontal fibers common across visual areas. These results raise the possibility
that iTWs are a new, dynamic mechanism of gain control. In this competitive renewal, this experiment- and
theory-driven team is well positioned to conduct experiments to test this role for iTWs by uncovering their
connection to specific patterns of connectivity in the visual system. This work will progress in three Specific
Aims. Aim 1: Test the hypothesis that iTWs fall into distinct motifs that regulate neural response gain and
perception in a feature-selective manner. The team’s network model predicts that clustered, feature-specific
connectivity among cortical columns in area MT will create iTWs that traverse subnetworks of like-tuned neurons.
They will test this theory-driven prediction in recordings from Area MT. Aim 2: Test the prediction that iTWs vary
in their impact and timing across layers of the cortical column. Using combined laminar and ECoG array
recordings, they will examine the impact of iTWs in the supragranular, granular, and infragranular layers of area
MT. Aim 3: Test competing published models of iTWs that make opposite predictions about their role in behavior.
One class of models predicts that iTWs drive pairwise correlations in ongoing undriven activity (so-called “noise
correlations”), which impair sensory discrimination. iTWs are thus, according to these models, a source of
information-limiting correlations that need to be diminished to improve sensory processing. The model of iTWs
developed by this team predicts, instead, that iTWs make no measurable contribution to pairwise correlations in
undriven activity and that they improve sensory processing by regulating the gain of sensory evoked responses,
an effect analogous to the benefits that stem from attention-dependent regulation of gain. Taken together, the
proposed experiments will elucidate the neural mechanisms underlying iTWs and probe their roles in both
detection and discrimination of stimuli. In addition, these experiments will test a new hypothesis about the role...

## Key facts

- **NIH application ID:** 10909368
- **Project number:** 5R01EY028723-06
- **Recipient organization:** SALK INSTITUTE FOR BIOLOGICAL STUDIES
- **Principal Investigator:** Lyle Edward Muller
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $459,020
- **Award type:** 5
- **Project period:** 2018-09-30 → 2027-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10909368

## Citation

> US National Institutes of Health, RePORTER application 10909368, Spatiotemporal patterns of neural activity and their role in perception (5R01EY028723-06). Retrieved via AI Analytics 2026-06-10 from https://api.ai-analytics.org/grant/nih/10909368. Licensed CC0.

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