Corollary discharge theory

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The corollary discharge theory (CD) of motion perception helps understand how the brain can detect motion through the visual system, even though the body is not moving. When a signal is sent from the motor cortex of the brain to the eye muscles, a copy of that signal (see efference copy) is sent through the brain as well. The brain does this in order to distinguish real movements in the visual world from our own body and eye movement. [1] The original signal and copy signal are then believed to be compared somewhere in the brain. Such a structure has not yet been identified, but it is believed to be the Medial Superior Temporal Area (MST). [2] [3] The original signal and copy need to be compared in order to determine if the change in vision was caused by eye movement or movement in the world. If the two signals cancel then no motion is perceived, but if they do not cancel then the residual signal is perceived as motion in the real world. [3] Without a corollary discharge signal, the world would seem to spin around every time the eyes moved. [4] It is important to note that corollary discharge and efference copy are sometimes used synonymously, they were originally coined for much different applications, with corollary discharge being used in a much broader sense. [5]

Contents

Discovery

The first scientific research study looking at corollary discharge was done by Descartes in 1664 when he published his book the Treatise of Man. He was studying apparent motion and developed early theories in an error of the mind to account for efferent signals centuries before corollary discharge theories developed. [6] In his experiment he would take his finger and press it on the side of his eye. In doing this he would move the image across his retina. A signal was then sent to the brain saying that the image had moved and because there was no efference copy signal sent as well, his brain perceived motion. [7] The term corollary discharge was finally coined in 1950 by Roger Sperry while doing studies on fish. [8]

Physiology

When trying to map out how corollary discharge works in the brain, it is important to begin with the superior colliculus. It is responsible for receiving visual signals from the retina.[ medical citation needed ] In studies done on primate brains, a corollary discharge pathway has been found to begin in the superior colliculus. [4] After receiving current information about the visual field, a corollary discharge signal is sent from the superior colliculus to the frontal eye field, via the medial dorsal nucleus of the thalamus. [4] The frontal eye field plays a very important role when it comes to eye movements. [9] Particularly the frontal eye field is responsible for much of the saccadic eye movements that eyes make. [10] Once the frontal eye field is activated by the corollary discharge signal, it sends a predictive signal to the occipital lobe. This signal essentially predicts what the visual field should look like after an eye movement. A signal is sent back from the occipital lobe to the frontal eye field describing actual visual input. [3] In summary, the corollary discharge pathway is responsible for helping guide eye movements as well as keeping stable visual perception. Recent studies suggest that deficiencies within this pathway could be responsible for difficulties that schizophrenic patients have with controlling their own movements. [11]

Related Research Articles

<span class="mw-page-title-main">Visual cortex</span> Region of the brain that processes visual information

The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalamus and then reaches the visual cortex. The area of the visual cortex that receives the sensory input from the lateral geniculate nucleus is the primary visual cortex, also known as visual area 1 (V1), Brodmann area 17, or the striate cortex. The extrastriate areas consist of visual areas 2, 3, 4, and 5.

<span class="mw-page-title-main">Sense of balance</span> Physiological sense regarding posture

The sense of balance or equilibrioception is the perception of balance and spatial orientation. It helps prevent humans and nonhuman animals from falling over when standing or moving. Equilibrioception is the result of a number of sensory systems working together; the eyes, the inner ears, and the body's sense of where it is in space (proprioception) ideally need to be intact.

Blindsight is the ability of people who are cortically blind to respond to visual stimuli that they do not consciously see due to lesions in the primary visual cortex, also known as the striate cortex or Brodmann Area 17. The term was coined by Lawrence Weiskrantz and his colleagues in a paper published in a 1974 issue of Brain. A previous paper studying the discriminatory capacity of a cortically blind patient was published in Nature in 1973. The assumed existence of blindsight is controversial, with some arguing that it is merely degraded conscious vision.

<span class="mw-page-title-main">Lateral geniculate nucleus</span> Component of the visual system in the brains thalamus

In neuroanatomy, the lateral geniculate nucleus is a structure in the thalamus and a key component of the mammalian visual pathway. It is a small, ovoid, ventral projection of the thalamus where the thalamus connects with the optic nerve. There are two LGNs, one on the left and another on the right side of the thalamus. In humans, both LGNs have six layers of neurons alternating with optic fibers.

<span class="mw-page-title-main">Pulvinar nuclei</span>

The pulvinar nuclei or nuclei of the pulvinar are the nuclei located in the thalamus. As a group they make up the collection called the pulvinar of the thalamus, usually just called the pulvinar.

Magnocellular cells, also called M-cells, are neurons located within the magnocellular layer of the lateral geniculate nucleus of the thalamus. The cells are part of the visual system. They are termed "magnocellular" since they are characterized by their relatively large size compared to parvocellular cells.

<span class="mw-page-title-main">Superior colliculus</span> Structure in the midbrain

In neuroanatomy, the superior colliculus is a structure lying on the roof of the mammalian midbrain. In non-mammalian vertebrates, the homologous structure is known as the optic tectum, or optic lobe. The adjective form tectal is commonly used for both structures.

<span class="mw-page-title-main">Pretectal area</span> Structure in the midbrain which mediates responses to ambient light

In neuroanatomy, the pretectal area, or pretectum, is a midbrain structure composed of seven nuclei and comprises part of the subcortical visual system. Through reciprocal bilateral projections from the retina, it is involved primarily in mediating behavioral responses to acute changes in ambient light such as the pupillary light reflex, the optokinetic reflex, and temporary changes to the circadian rhythm. In addition to the pretectum's role in the visual system, the anterior pretectal nucleus has been found to mediate somatosensory and nociceptive information.

<span class="mw-page-title-main">Eye movement</span> Movement of the eyes

Eye movement includes the voluntary or involuntary movement of the eyes. Eye movements are used by a number of organisms to fixate, inspect and track visual objects of interests. A special type of eye movement, rapid eye movement, occurs during REM sleep.

The pars reticulata (SNpr) is a portion of the substantia nigra and is located lateral to the pars compacta. Most of the neurons that project out of the pars reticulata are inhibitory GABAergic neurons.

<span class="mw-page-title-main">Smooth pursuit</span> Type of eye movement used for closely following a moving object

In the scientific study of vision, smooth pursuit describes a type of eye movement in which the eyes remain fixated on a moving object. It is one of two ways that visual animals can voluntarily shift gaze, the other being saccadic eye movements. Pursuit differs from the vestibulo-ocular reflex, which only occurs during movements of the head and serves to stabilize gaze on a stationary object. Most people are unable to initiate pursuit without a moving visual signal. The pursuit of targets moving with velocities of greater than 30°/s tends to require catch-up saccades. Smooth pursuit is asymmetric: most humans and primates tend to be better at horizontal than vertical smooth pursuit, as defined by their ability to pursue smoothly without making catch-up saccades. Most humans are also better at downward than upward pursuit. Pursuit is modified by ongoing visual feedback.

<span class="mw-page-title-main">Frontal eye fields</span> Region of the frontal cortex of the brain

The frontal eye fields (FEF) are a region located in the frontal cortex, more specifically in Brodmann area 8 or BA8, of the primate brain. In humans, it can be more accurately said to lie in a region around the intersection of the middle frontal gyrus with the precentral gyrus, consisting of a frontal and parietal portion. The FEF is responsible for saccadic eye movements for the purpose of visual field perception and awareness, as well as for voluntary eye movement. The FEF communicates with extraocular muscles indirectly via the paramedian pontine reticular formation. Destruction of the FEF causes deviation of the eyes to the ipsilateral side.

<span class="mw-page-title-main">Medial dorsal nucleus</span>

The medial dorsal nucleus is a large nucleus in the thalamus.

In physiology, an efference copy or efferent copy is an internal copy of an outflowing (efferent), movement-producing signal generated by an organism's motor system. It can be collated with the (reafferent) sensory input that results from the agent's movement, enabling a comparison of actual movement with desired movement, and a shielding of perception from particular self-induced effects on the sensory input to achieve perceptual stability. Together with internal models, efference copies can serve to enable the brain to predict the effects of an action.

Sensory-motor coupling is the coupling or integration of the sensory system and motor system. Sensorimotor integration is not a static process. For a given stimulus, there is no one single motor command. "Neural responses at almost every stage of a sensorimotor pathway are modified at short and long timescales by biophysical and synaptic processes, recurrent and feedback connections, and learning, as well as many other internal and external variables".

<span class="mw-page-title-main">Inferior pulvinar nucleus</span>

Inferior pulvinar nucleus is one of four traditionally anatomically distinguished nuclei of the pulvinar of the thalamus. The other three nuclei of the pulvinar are called lateral, anterior and medial pulvinar nuclei.

<span class="mw-page-title-main">Lateral pulvinar nucleus</span>

Lateral pulvinar nucleus is one of four traditionally anatomically distinguished nuclei of the pulvinar of the thalamus. The other three nuclei of the pulvinar are called anterior, inferior and medial pulvinar nuclei.

<span class="mw-page-title-main">Medial pulvinar nucleus</span>

Medial pulvinar nucleus is one of four traditionally anatomically distinguished nuclei of the pulvinar of the thalamus. The other three nuclei of the pulvinar are called lateral, inferior and anterior pulvinar nuclei.

<span class="mw-page-title-main">Peter Schiller (neuroscientist)</span> Neuroscientist

Peter H. Schiller is a professor emeritus of Neuroscience in the Department of Brain and Cognitive Sciences at the Massachusetts Institute of Technology (MIT). He is well known for his work on the behavioral, neurophysiological and pharmacological studies of the primate visual and oculomotor systems.

Michael E. Goldberg, also known as Mickey Goldberg, is an American neuroscientist and David Mahoney Professor at Columbia University. He is known for his work on the mechanisms of the mammalian eye in relation to brain activity. He served as president of the Society for Neuroscience from 2009 to 2010.

References

  1. ↑ Schwartz BL, Krantz JH. "Corollary Discharge". Sensation and Perception. SAGE Publications. Retrieved 2020-03-09.
  2. ↑ Heeger D (2006). "Perception Lecture Notes: Visual Motion Perception". Department of Psychology, New York University. Retrieved 2020-03-17.
  3. 1 2 3 Crapse TB, Sommer MA (December 2008). "Corollary discharge circuits in the primate brain". Current Opinion in Neurobiology. 18 (6): 552–7. doi:10.1016/j.conb.2008.09.017. PMC   2702467 . PMID   18848626.
  4. 1 2 3 Crapse TB, Sommer MA (August 2008). "Corollary discharge across the animal kingdom". Nature Reviews. Neuroscience. 9 (8): 587–600. doi:10.1038/nrn2457. PMC   5153363 . PMID   18641666.
  5. ↑ McCloskey DI (2011). "Corollary Discharges: Motor Commands and Perception". Comprehensive Physiology. American Cancer Society. pp. 1415–1447. doi:10.1002/cphy.cp010232. ISBN   978-0-470-65071-4.
  6. ↑ Stark L, Bridgeman B (October 1983). "Role of corollary discharge in space constancy". Perception & Psychophysics. 34 (4): 371–80. doi: 10.3758/bf03203050 . PMID   6657439.
  7. ↑ Bridgeman B (2011). "Visual Stability" (PDF). The Oxford Handbook of Eye Movements. Oxford: Oxford University Press. pp. 511–521. doi:10.1093/oxfordhb/9780199539789.013.0028. ISBN   978-0-19-953978-9.
  8. ↑ Sperry RW (December 1950). "Neural basis of the spontaneous optokinetic response produced by visual inversion". Journal of Comparative and Physiological Psychology. 43 (6): 482–9. doi:10.1037/h0055479. PMID   14794830.
  9. ↑ Schall JD (June 2004). "On the role of frontal eye field in guiding attention and saccades". Vision Research. 44 (12): 1453–67. doi: 10.1016/j.visres.2003.10.025 . PMID   15066404. S2CID   12397479.
  10. ↑ Pouget P (February 2015). "The cortex is in overall control of 'voluntary' eye movement". Eye. 29 (2): 241–5. doi:10.1038/eye.2014.284. PMC   4330293 . PMID   25475239.
  11. ↑ Cavanaugh J, McAlonan K, Wurtz RH (August 2020). "Organization of Corollary Discharge Neurons in Monkey Medial Dorsal Thalamus". The Journal of Neuroscience. 40 (33): 6367–6378. doi:10.1523/JNEUROSCI.2344-19.2020. PMC   7424873 . PMID   32680937.
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