  A theoretical framework is proposed for the understanding of verbal
perception -- the conversion of words into meaning, modeled as a compromise
between lexical demands and contextual constraints -- and the theory is tested
against experiments on short-term memory. The observation that lists of short
words are recalled better than lists of long ones has been a long-standing
subject of controversy, further complicated by the apparent inversion of the
effect for mixed lists. In the framework here proposed, these behaviors emerge
as an effect of the different level of localization of short and long words in
semantic space. Events corresponding to the recognition of a nonlocal word have
a clustering property in phase space, which facilitates associative retrieval.
The standard word-length effect arises directly from this property, and the
inverse effect from its breakdown. An analysis of data from the PEERS
experiments (Healey and Kahana, 2016) confirms the main predictions of the
theory. Further predictions are listed and new experiments are proposed.
Finally, an interpretation of the above results is presented.
