ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

5aSC9. Vowel perception in dyslexic subjects.

Carol B. Bertucci

MGH Inst. of Health Professions, 101 Merrimac St., Boston, MA 02114

It has been demonstrated by some investigators that poor readers may have less well-defined phonological categories than good readers. Whereas these studies have considered the perception of consonants, the current study investigated the percetion of the vowels /(small capital eye), (cursive beta), (ae ligature)/ by individuals with dyslexia. Perception was also compared with production and with other measures considered important for reading. A small-group case-study design was employed, in which the patterns of performance of one adult and three children with varying degrees of dyslexia were examined individually and compared with age-matched control subjects. An identification task was used, in which subjects matched synthesized stimuli, equally spaced along a continuum of F1/F2, to pictures of pit, pet, and pat. A set of intermediate stimuli was administered at a later date. The findings of this exploratory study suggest that subjects vary in their ability to perceive the vowels /(small capital eye), (cursive beta), (ae ligature)/ according to the severity of their reading/spelling impairment. Differences in perception were noted in the sharpness of the boundaries between phonemes and in the tendency to give abberant responses to test stimuli. Shifts in perception were also noted across days and stimulus sets in some individuals.