Show Reference: "Cross-Modal Synthesis in the Midbrain Depends on Input from Cortex"

Cross-Modal Synthesis in the Midbrain Depends on Input from Cortex Journal of Neurophysiology, Vol. 71, No. 1. (January 1994), pp. 429-432 by Mark T. Wallace, Barry E. Stein
@article{wallace-and-stein-1994,
    abstract = {1. The synthesis of information from different sensory modalities in the superior colliculus is an important precursor of attentive and orientation behavior. 2. This integration of multisensory information is critically dependent on inputs from a small area of association cortex, the anterior ectosylvian sulcus. Removal of these corticotectal influences can have a remarkably specific effect: it can eliminate multisensory integration in superior colliculus neurons while leaving their responses to unimodal cues intact. 3. Apparently, some of the associative functions of cortex are accomplished via its target neurons in the midbrain.},
    address = {Department of Physiology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0551.},
    author = {Wallace, Mark T. and Stein, Barry E.},
    issn = {0022-3077},
    journal = {Journal of Neurophysiology},
    keywords = {biology, cortex, multisensory-integration, sc},
    month = jan,
    number = {1},
    pages = {429--432},
    pmid = {8158240},
    posted-at = {2013-10-14 11:08:29},
    priority = {2},
    title = {{Cross-Modal} Synthesis in the Midbrain Depends on Input from Cortex},
    url = {http://view.ncbi.nlm.nih.gov/pubmed/8158240},
    volume = {71},
    year = {1994}
}

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Modulatory input from uni-sensory, parietal regions to SC follows the principles of modality-matching and cross-modality:

A deep SC neuron (generally) only receives modulatory input related to some modality if it also receives primary input from that modality.

Modulatory input related to some modality only affects responses to primary input from the other modalities.

Deactivating regions in AES or lateral suprasylvian cortex responsive to some modality can completely eliminate responses of deep SC neurons to that modality.

Wallace and Stein argue that some deep SC neurons receive input from some modalities only via cortex.

The most important cortical input to the SC (in cats) comes from layer V cortical neurons from a number of sub-regions of the anterior ectosylvian sulcus (AES):

  • anterior ectosylvian visual area (AEV)
  • the auditory field of AES (FAES)
  • and the fourth somatosensory area (SIV)

These populations in themselves are uni-sensory.

Without an intact association cortex (or LIP), SC neurons cannot develop or maintain cross-modal integration.

(Neither multi-sensory enhancement nor depression.)