Dissertation - Michael Becker

(66) The difference in rates of alternation between high and non-high vowels, by sizeand place, in the lexicon and in the MGL results.25%CVCVt20%15%CVkMGL predictionsCVC10%5%CVCtCVCVCVpCVCk0% CVCVkCVt CVCVCVpCVCp-60% -40% -20% 0% 20% 40%-5%-10%lexicon2.5.3 DiscussionThe MGL’s impressive performance in matching the lexical trends of Turkish voicingalternations were to its detriment. In out-performing the participants of the experimentdescribed in §2.3, it failed to mimic human behavior.The MGL is a powerful learner for phonological patterns. Given nothing but a list ofparadigms and the natural classes that the segments in it form, it learned that Turkish hasvoicing alternations and that there are factors that are correlated with their distribution.However, since the MGL lacks a theory of possible interactions between phonologicalelements, it could not ignore the predictive power of vowel height and backness indetermining the alternating or non-alternating status of attested nouns, and it used all thecorrelations it found in predicting the status of novel forms.Humans, I argue, are biased to ignore any effect that vowel quality might have onthe voicing of a neighboring consonant. This one and the same bias is observed in two68