Corollary discharge, also known as reafference or reafferent discharge, is a neural mechanism in which the motor control system of the brain sends out a signal to the sensory systems in order to confirm the action it has just taken. This mechanism allows the brain to verify that its commands have been successfully carried out. This is a crucial process for coordinating movements and maintaining a sense of proprioception. Corollary discharge has been observed in a variety of species, including humans, and has been linked to the integration of sensory information and motor commands.
The concept of corollary discharge was first proposed in the 1950s by neuroscientist William McCulloch. He suggested that the brain sends out a signal to the sensory systems after every motor command in order to ensure that the command was successfully carried out. This signal is known as a corollary discharge. In humans, corollary discharge is thought to be related to the conscious perception of movement.
Corollary discharge is believed to play an important role in the coordination of movement. It helps the brain to accurately predict the sensory feedback it will receive when a movement is made. This enables the brain to adjust the motor command if necessary, resulting in smoother and more coordinated movements. Corollary discharge is also thought to be involved in the maintenance of a sense of proprioception, or the awareness of one’s body position in space.
The neural mechanisms underlying corollary discharge are still not fully understood. However, recent studies have suggested that the process involves the integration of two types of signals: an efference copy and a feedback signal. The efference copy is a copy of the motor command sent to the sensory systems. The feedback signal is the sensory information received by the brain after the movement has been completed. These two signals are integrated in the brain to form a corollary discharge signal.
The role of corollary discharge in the coordination of movement and the maintenance of a sense of proprioception has been demonstrated in a variety of species, including humans. Recent studies have also suggested that corollary discharge is involved in the integration of sensory information and motor commands, and may play an important role in the conscious perception of movement.
References
Ghez, C., Gordon, J., & Ghilardi, M. (1995). Corollary discharge: A neural mechanism for sensory-motor integration. In M. Jeannerod (Ed.), Attention and performance XV: Conscious and nonconscious information processing (pp. 281–313). Cambridge, MA: MIT Press.
McCulloch, W. S. (1955). The anatomical basis of corollary discharge. British Journal of Animal Behaviour, 3(1), 2-7.
Schiff, S. J., & Kording, K. P. (2011). Proprioception: A Bayesian perspective. Current Biology, 21(18), R800–R813.
Wolpert, D. M., Ghahramani, Z., & Jordan, M. I. (1995). An internal model for sensorimotor integration. Science, 269(5232), 1880–1882.