Computer-implemented method for operating an artificial neural network, ANN, which processes inputs in a sequence of layers (12a-12c, 13a-13b) to form outputs, the method comprising the following steps: • within the ANN, at least one iterative block composed of one or more layers (12a-12c) is defined, which is to be executed a number of times; • a number J of iterations is defined which is a maximum number of times this iterative block is intended to be executed; • an input of the iterative block is mapped onto an output by the iterative block; • this output is fed to the iterative block again as input and is in turn mapped onto a new output by the iterative block; • after the iterations of the iterative block have been completed, the output supplied by the iterative block is fed as input to the layer of the ANN following the iterative block or is provided as output of the ANN, • wherein parameters that characterize the behaviour of the layers (12a-12c) in the iterative block are defined or modulated on the basis of the output of an auxiliary ANN, which receives the following as inputs: ∘ an input of the iterative block, or ∘ a processing product formed in a layer of the ANN downstream of the iterative block, or ∘ the parameters that characterize the behaviour of the iterative block, or ∘ a continuous index of the iteration currently being executed by the iterative block, and • wherein at least the iterative block of the ANN is executed (132, 152) on at least one computing unit using machine instructions that exclusively access an internal memory of this computing unit. • within the ANN, at least one iterative block composed of one or more layers (12a-12c) is defined, which is to be executed a number of times; • a number J of iterations is defined which is a maximum number of times this iterative block is intended to be executed; • an input of the iterative block is mapped onto an output by the iterative block; • this output is fed to the iterative block again as input and is in turn mapped onto a new output by the iterative block; • after the iterations of the iterative block have been completed, the output supplied by the iterative block is fed as input to the layer of the ANN following the iterative block or is provided as output of the ANN, • wherein parameters that characterize the behaviour of the layers (12a-12c) in the iterative block are defined or modulated on the basis of the output of an auxiliary ANN, which receives the following as inputs: ∘ an input of the iterative block, or ∘ a processing product formed in a layer of the ANN downstream of the iterative block, or ∘ the parameters that characterize the behaviour of the iterative block, or ∘ a continuous index of the iteration currently being executed by the iterative block, and ∘ an input of the iterative block, or ∘ a processing product formed in a layer of the ANN downstream of the iterative block, or ∘ the parameters that characterize the behaviour of the iterative block, or ∘ a continuous index of the iteration currently being executed by the iterative block, • wherein at least the iterative block of the ANN is executed (132, 152) on at least one computing unit using machine instructions that exclusively access an internal memory of this computing unit.