There are a number of studies suggesting that sensory input is processed by comparison with a prediction of that input, and a natural next question is: what is the prediction derived from? Other sensory modalities, or also (in the case of self produced sensations) dynamic integration of the output motor commands? Tommorrow, at Sensorimotor Journal Club, I will present an older classic paper that looked for evidence of efference copy of motor output being used this way:

 

Wolpert, D. M., Ghahramani, Z., & Jordan, M. I. (1995). An internal model for sensorimotor integration. Science, 269(5232), 1880-1882. (link to pdf of article)

 

On the basis of computational studies it has been proposed that the central nervous system internally simulates the dynamic behavior of the motor system in planning, control, and learning; the existence and use of such an internal model is still under debate. A sensorimotor integration task was investigated in which participants estimated the location of one of their hands at the end of movements made in the dark and under externally imposed forces. The temporal propagation of errors in this task was analyzed within the theoretical framework of optimal state estimation. These results provide direct support for the existence of an internal model.