“∞-Former: Infinite Memory Transformer”, 2021-09-01 (; backlinks; similar):
Transformers are unable to model long-term memories effectively, since the amount of computation they need to perform grows with the context length.
While variations of efficient transformers have been proposed, they all have a finite memory capacity and are forced to drop old information.
In this paper, we propose the ∞-former, which extends the vanilla transformer with an unbounded long-term memory. By making use of a continuous-space attention mechanism to attend over the long-term memory, the ∞-former’s attention complexity becomes independent of the context length, trading off memory length with precision.
In order to control where precision is more important, ∞-former maintains “sticky memories” being able to model arbitrarily long contexts while keeping the computation budget fixed.
Experiments on a synthetic sorting task, language modeling, and document grounded dialogue generation demonstrate the ∞-former’s ability to retain information from long sequences.
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