Susan C. Renda
John W. Hawks
Richard Klich
School of Speech Pathol. and Audiol., Kent State Univ., Kent, OH 44242
Three experiments were undertaken to investigate the validity and strength of the perceptual magnet effect in adults. First, the original perceptual magnet experiment [P. K. Kuhl, Percept. Psychophys. 50, 93--107 (1991)] was directly replicated with adults, using Kuhl's stimulus parameters. These subjects were then tested with the AAXX protocol used to test monkeys in Kuhl (1991). Generalization scores were computed for subjects under both conditions and compared. A second group of subjects rated a large number of /KY/ vowel tokens in the next experiment. Average ratings were computed and a prototype (P) and nonprototype (NP) were chosen based on them. Variants of each were synthesized as in Kuhl (1991). Subjects rated the goodness of each variant on a scale from 1 to 7. In addition they assigned a 0 to any token perceived as not belonging to the /i/ category. The subjects then participated in the perceptual magnet experiment. Data from trials containing stimuli assigned 0 were excluded from analysis. In the third experiment, a large number of /EH/ vowel tokens were rated and P and NP were chosen. Variants were synthesized and rated and the perceptual magnet effect experiment was again conducted using these tokens. Results and implications of these experiments will be discussed.