Role of corollary discharge in space constancy

The most common neural representations for spatial attention encode locations retinotopically, relative to center of gaze. To keep track of visual objects across saccades or to orient toward sounds, retinotopic representations must be combined with information about the rotation of one's own eyes in the orbits. Although gaze input is critical for a correct allocation of attention, the source of this input has so far remained unidentified. Two main signals are available: corollary discharge (copy of oculomotor command) and oculoproprioception (feedback from extraocular muscles). Here we asked whether the oculoproprioceptive signal relayed from the somatosensory cortex contributes to coding the locus of attention. We used continuous theta burst stimulation (cTBS) over a human oculoproprioceptive area in the postcentral gyrus (S1EYE). S1EYE-cTBS reduces proprioceptive processing, causing ∼1° underestimation of gaze angle. Participants discriminated visual targets whose location was cued in a nonvisual modality. Throughout the visual space, S1EYE-cTBS shifted the locus of attention away from the cue by ∼1°, in the same direction and by the same magnitude as the oculoproprioceptive bias. This systematic shift cannot be attributed to visual mislocalization. Accuracy of open-loop pointing to the same visual targets, a function thought to rely mainly on the corollary discharge, was unchanged. We argue that oculoproprioception is selective for attention maps. By identifying a potential substrate for the coupling between eye and attention, this study contributes to the theoretical models for spatial attention.

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The role of the human thalamus in processing corollary discharge

Brain ◽

10.1093/brain/awh474 ◽

2005 ◽

Vol 128 (5) ◽

pp. 1139-1154 ◽

Cited By ~ 71

Author(s):

C. Bellebaum ◽

I. Daum ◽

B. Koch ◽

M. Schwarz ◽

K.-P. Hoffmann

Keyword(s):

Corollary Discharge ◽

Human Thalamus

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Using a classic paper by Bell as a platform for discussing the role of corollary discharge-like signals in sensory perception and movement control

AJP Advances in Physiology Education ◽

10.1152/advan.00080.2013 ◽

2014 ◽

Vol 38 (1) ◽

pp. 12-19

Author(s):

Aaron L. Cecala

Keyword(s):

Electric Fish ◽

Movement Control ◽

Corollary Discharge ◽

Scientific Investigations ◽

Posterior Lateral Line ◽

Neural Substrate ◽

Neurophysiological Data ◽

Afferent Inputs ◽

Classic Paper

Decades of behavioral observations have shown that invertebrate and vertebrate species have the ability to distinguish between self-generated afferent inputs versus those that are generated externally. In the present article, I describe activities focused around the discussion of a classic American Physiological Society paper by Curtis C. Bell that lays the foundation for students to investigate the neural substrate underlying this ability. Students will leave this activity being able to 1) describe the technical aspects and limitations of an electric fish preparation commonly used to acquire single unit (extracellular) neurophysiological data, 2) provide physiological evidence showing that the activity of principal cells in the posterior lateral line lobe of the electric fish brain reflects that of a reafference comparator that could be used in dissociating self-generated versus externally generated sensory signals, and 3) knowledgeably discuss hypotheses concerning the role of corollary discharge and cerebellar-like structures in vertebrate and invertebrate species. The skills and background knowledge gained in this activity lay the platform for advanced study of scientific investigations into sensory, motor, and cognitive processes in undergraduate, graduate, or medical school curricula.

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What the Brain Stem Tells the Frontal Cortex. II. Role of the SC-MD-FEF Pathway in Corollary Discharge

Journal of Neurophysiology ◽

10.1152/jn.00740.2003 ◽

2004 ◽

Vol 91 (3) ◽

pp. 1403-1423 ◽

Cited By ~ 138

Author(s):

Marc A. Sommer ◽

Robert H. Wurtz

Keyword(s):

Cerebral Cortex ◽

Visual Field ◽

Relay Node ◽

Corollary Discharge ◽

Frontal Eye Field ◽

Double Step ◽

Eye Field ◽

Overall Performance ◽

The Brain

One way we keep track of our movements is by monitoring corollary discharges or internal copies of movement commands. This study tested a hypothesis that the pathway from superior colliculus (SC) to mediodorsal thalamus (MD) to frontal eye field (FEF) carries a corollary discharge about saccades made into the contralateral visual field. We inactivated the MD relay node with muscimol in monkeys and measured corollary discharge deficits using a double-step task: two sequential saccades were made to the locations of briefly flashed targets. To make second saccades correctly, monkeys had to internally monitor their first saccades; therefore deficits in the corollary discharge representation of first saccades should disrupt second saccades. We found, first, that monkeys seemed to misjudge the amplitudes of their first saccades; this was revealed by systematic shifts in second saccade end points. Thus corollary discharge accuracy was impaired. Second, monkeys were less able to detect trial-by-trial variations in their first saccades; this was revealed by reduced compensatory changes in second saccade angles. Thus corollary discharge precision also was impaired. Both deficits occurred only when first saccades went into the contralateral visual field. Single-saccade generation was unaffected. Additional deficits occurred in reaction time and overall performance, but these were bilateral. We conclude that the SC-MD-FEF pathway conveys a corollary discharge used for coordinating sequential saccades and possibly for stabilizing vision across saccades. This pathway is the first elucidated in what may be a multilevel chain of corollary discharge circuits extending from the extraocular motoneurons up into cerebral cortex.

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