Corollary discharge circuits in the primate brain

Trinity B Crapse; Marc A Sommer

doi:10.1016/j.conb.2008.09.017

A circuit for saccadic suppression in the primate brain

Journal of Neurophysiology ◽

10.1152/jn.00679.2016 ◽

2017 ◽

Vol 117 (4) ◽

pp. 1720-1735 ◽

Cited By ~ 9

Author(s):

Rebecca A. Berman ◽

James Cavanaugh ◽

Kerry McAlonan ◽

Robert H. Wurtz

Keyword(s):

Eye Movements ◽

Corollary Discharge ◽

Saccadic Suppression ◽

Visual Signals ◽

Visual Responses ◽

Visual Neuroscience ◽

Primate Brain ◽

Complete Circuit ◽

Visual Area Mt ◽

Visual Hemifields

Saccades should cause us to see a blur as the eyes sweep across a visual scene. Specific brain mechanisms prevent this by producing suppression during saccades. Neuronal correlates of such suppression were first established in the visual superficial layers of the superior colliculus (SC) and subsequently have been observed in cortical visual areas, including the middle temporal visual area (MT). In this study, we investigated suppression in a recently identified circuit linking visual SC (SCs) to MT through the inferior pulvinar (PI). We examined responses to visual stimuli presented just before saccades to reveal a neuronal correlate of suppression driven by a copy of the saccade command, referred to as a corollary discharge. We found that visual responses were similarly suppressed in SCs, PI, and MT. Within each region, suppression of visual responses occurred with saccades into both visual hemifields, but only in the contralateral hemifield did this suppression consistently begin before the saccade (~100 ms). The consistency of the signal along the circuit led us to hypothesize that the suppression in MT was influenced by input from the SC. We tested this hypothesis in one monkey by inactivating neurons within the SC and found evidence that suppression in MT depends on corollary discharge signals from motor SC (SCi). Combining these results with recent findings in rodents, we propose a complete circuit originating with corollary discharge signals in SCi that produces suppression in visual SCs, PI, and ultimately, MT cortex. NEW & NOTEWORTHY A fundamental puzzle in visual neuroscience is that we frequently make rapid eye movements (saccades) but seldom perceive the visual blur accompanying each movement. We investigated neuronal correlates of this saccadic suppression by recording from and perturbing a recently identified circuit from brainstem to cortex. We found suppression at each stage, with evidence that it was driven by an internally generated signal. We conclude that this circuit contributes to neuronal suppression of visual signals during eye movements.

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Corollary Discharge Contributions to Perceptual Continuity Across Saccades

Annual Review of Vision Science ◽

10.1146/annurev-vision-102016-061207 ◽

2018 ◽

Vol 4 (1) ◽

pp. 215-237 ◽

Cited By ~ 15

Author(s):

Robert H. Wurtz

Keyword(s):

Visual Field ◽

High Resolution ◽

Corollary Discharge ◽

Visual Stability ◽

Neuronal Mechanism ◽

Primate Brain ◽

Internal Signal ◽

Basic Characteristics ◽

Visual Continuity ◽

Perceptual Continuity

Our vision depends upon shifting our high-resolution fovea to objects of interest in the visual field. Each saccade displaces the image on the retina, which should produce a chaotic scene with jerks occurring several times per second. It does not. This review examines how an internal signal in the primate brain (a corollary discharge) contributes to visual continuity across saccades. The article begins with a review of evidence for a corollary discharge in the monkey and evidence from inactivation experiments that it contributes to perception. The next section examines a specific neuronal mechanism for visual continuity, based on corollary discharge that is referred to as visual remapping. Both the basic characteristics of this anticipatory remapping and the factors that control it are enumerated. The last section considers hypotheses relating remapping to the perceived visual continuity across saccades, including remapping's contribution to perceived visual stability across saccades.

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