Abstract:

In every language, some sequences of sounds are illegal. English, for instance, bans stressed lax vowels word-finally---[bI] cannot be an English word. Linguists traditionally attribute this to language-particular phonotactic rules. More recently, some psychologists have suggested instead that phonotactics is the emergent statistical property of the lexicon, caused by the frequency of some sequences and the rarity of others. The issue is tested here by comparing the effects of absolute phonotactic rules versus nonphonotactic lexical frequency differences on phonetic category boundaries. Stimuli are disyllabic English pseudowords ending in a stressed syllable whose vowel is ambiguous. One continuum is [gri] (very common in that position) to [grI] (illegal); another is [kri] (legal but very rare) to [krI] (illegal). Controls, with both end points legal, are [grich]-[grIch] and [krich-krIch]. The [I] end point's illegality should move the i--I boundary towards [I] compared with the controls. The rule theory predicts equal shifts for the [gr] and [kr] continuua; the statistical theory says it will be much larger for the frequent [gr]. [Work supported by NIH.]