Approximation of the effect of an electric field on neurons
For the function that defines the output of a node in artificial neuronal networks according to the given input, see Activation function.
The activating function is a mathematical formalism that is used to approximate the influence of an extracellular field on an axon or neurons.[1][2][3][4][5][6] It was developed by Frank Rattay and is a useful tool to approximate the influence of functional electrical stimulation (FES) or neuromodulation techniques on target neurons.[7] It points out locations of high hyperpolarization and depolarization caused by the electrical field acting upon the nerve fiber. As a rule of thumb, the activating function is proportional to the second-order spatial derivative of the extracellular potential along the axon.
^Rattay, F. (1986). "Analysis of Models for External Stimulation of Axons". IEEE Transactions on Biomedical Engineering (10): 974–977. doi:10.1109/TBME.1986.325670. S2CID33053720.
^Rattay, F. (1988). "Modeling the excitation of fibers under surface electrodes". IEEE Transactions on Biomedical Engineering. 35 (3): 199–202. doi:10.1109/10.1362. PMID3350548. S2CID27312507.
^Rattay, F. (1989). "Analysis of models for extracellular fiber stimulation". IEEE Transactions on Biomedical Engineering. 36 (7): 676–682. doi:10.1109/10.32099. PMID2744791. S2CID42935757.
^Rattay, F. (1998). "Analysis of the electrical excitation of CNS neurons". IEEE Transactions on Biomedical Engineering. 45 (6): 766–772. doi:10.1109/10.678611. PMID9609941. S2CID789370.