This paper contains some modifications to Back Propagation that aim to remove one of its failings without sacrificing power. Adaptively Parametrised Error Correcting Systems ( APECS ) are shown not to suffer from the sequential learning problem, and to be capable of solving EOR , higher order parity, and negation problems. This opens the w a y to development of connectionist models of associative learning and memory that do not suffer from "catastrophic interference", and may shed light on issues such as the episodic / semantic memory distinction.