The inventive method and apparatus include sensory devices (Fig. 1) that invariantly represent stimuli in the presence of processes that cause systematic sensor state transformations (Fig. 7). Such processes include: 1) alterations of the device's detector, 2) changes in the observational environment external to the sensory device and the stimuli, and 3) certain modifications of the presentation of the stimuli themselves. A specific embodiment of the present invention is an intelligent sensory device having a 'front end' comprised of such a representation 'engine' (Fig. 1). The detectors of such a sensory device need not be recalibrated, and its pattern analysis module need not be retrained, in order to account for the presence of the above-mentioned transformative processes. Another embodiment of the present invention is a communications system that encodes messages as representations of signals (Fig. 18). The message is not corrupted by signal transformations due to a wide variety of processes affecting the transmitters, receivers, and the channels between them.
SELF-REFERENTIAL METHOD AND APPARATUS FOR CREATING STIMULUS REPRESENTATIONS THAT ARE INVARIANT UNDER SYSTEMATIC TRANSFORMATIONS OF SENSOR STATES