[Memory blocking: facts, problems, and models]

The tip-of-the-tongue state, or memory blocking, has been investigated from the point of view of possibilities of its neural network modeling. The results of neuropsychological and neurobiological studies on memory blocking have been reviewed, and basic problems whose solution could contribute to the comprehension of this phenomenon have been formulated. One of such questions is the existence of a paradoxical discrepancy between the subjective assurance that a pattern is familiar and the impossibility to recollect it fully. To explain this discrepancy, we propose a biologically plausible neural network model of recognition demonstrating a radical superiority of the capacity for the recognition of a pattern as compared with its recollection.