Current Research Investigations of Corollary Discharge :: Biology Medicine Research Papers

Current Research Investigations of Corollary Discharge Corollary discharge assists both human and non-human animals distinguish between self-generated (internal) and external motor responses. By sending signals which report important information about movement commands and intension animals are able to accurately produce motor sequences with ease and coordination. When a motor command initiates an electric organ discharge, the signal transmits important information to the brain which serves as a feed-back mechanisms which assist with self-monitoring; this is formally defined as corollary discharge(6). Although the corollary discharge system is one of the most important systems which animals possess for the control and detection of motor movements, its specific neurological mapping is largely unknown. Many studies which investigate the specific nature of corollary discharge focus on either auditory or visual sensory perception. Current investigations of corollary discharge are commonly associated with the use non-human primates and humans who suffer from Schizophrenia. By using non-human primates for the investigation of the neuronal network of the corollary discharge system both invasive and non-invasive investigation may be explored. In addition, investigating Schizophrenics who suffer from auditory hallucinations, the inability to differentiate between spoken and thought speech (1), may also significantly contribute to the advancement and increased understandings of the corollary discharge systems. Sommer et. al., proposed a neuronal pathway for corollary discharge in non-human primates. He suggested that this pathway extends from the brainstem to the frontal cortex. Within the pathway the brain was to initiate movement as well as supply internal information which was then used by sensory systems to adjust for resultant changes(5). These adjustments were said to occur within the peripheral receptors and motor planning systems which would then prepare the body for future movements(5). Corollary discharge signals in Sommer's study were identified as movement related activity which projected upstream (up the spinal cord) away from motor neurons, transmitting information but not causing any actual movement (4). By measuring the neuronal firing of the superior colliculus in the frontal cortex during normal and stimulated saccade movements of the eye, Sommer measured the corollary discharge signals in monkeys. The results of Sommer's study suggested that non-human primates did i n fact transmit corollary discharge signals during eye saccades which was suggestive of a brainstem to frontal cortex pathway for transmission. While Sommer's study provided novel and interesting ideas in regard to the specific pathway of corollary discharge, it focused largely of saccadic eye movements in non-human primates.