Director: Danny R. Moates
You can change the non-word TEEBLE into a real word by changing just one vowel or by changing just one consonant. The vowel word is table and the consonant word is feeble. Virtually all research studies using this task find that people can find the vowel word more easily and faster than they can find the consonant word. Why?
The sounds of a language can be analyzed into a set of distinctive features, based on the way the sounds are produced. The feature “voice” is present when the vocal cords vibrate, so all the vowels and such consonants as b, d, g, v, and z have the feature “voice.” The feature “consonantal” is present when there is some constriction in the air flow, so all the consonants and none of the vowels have the feature “consonantal.”
Are these features found in the words in our mental lexicon? Does GO have both the feature “voice” and the feature “consonantal” for the G and the feature “voice” but not the feature “consonantal” for the O?
To test this question we give people non-words such as SANY and ask them to change the S to make a real word. The change to ZANY should be easy because S and Z differ in just one feature (voicing). We also give them another pair such as SUMBER and also ask them to change the S to make a real word. The change to LUMBER is predicted to be harder because S and L differ in four distinctive features.
Adding a suffix to a verb sometimes produces no change in the verb, e.g., TREAT + MENT = TREATMENT. Other suffixes can produce a big change in the verb, e.g., DECIDE + ION = DECISION. The I vowel changes its pronunciation, the second D changes its pronunciation, the second D moves out of the second syllable and into the third, and more. Our hypothesis is that the more changes there are, the harder it is to process the suffixed form. The project has special implications for the study of reading.