Case, Pamela S.

When adults attempt to learn new speech sounds, they do so in the context of the phonology of their native language. The purpose of the present work is to investigate the nature of the learning process; that is, to examine, in individuals, (1) the process of acquiring a new phonetic category, (2) the impact of learning a new phonetic category on a similar, existing category, and (3) transfer of learning to a novel phonetic context. Monolingual American English speakers were required to learn the Hindi voiced, unaspirated, dental stop consonant. Two synthetic speech continua (one voiced, the other voiceless) were created, spanning a range from Hindi dental to American English alveolar stop consonants. Subjects underwent a perceptual mapping procedure that included identification, judged goodness, and difference-rating tasks in order to establish how they perceived the stimuli initially. Then they participated in a two-alternative, forced-choice training program using only voiced, natural speech stimuli. Progress was monitored throughout training. Following training, the mapping procedure was repeated with both the voiced and voiceless continua. After at least a two-week delay with no further training, subjects participated in a follow-up test. Results indicate that the nature of change during the learning process depends on how the individual listener perceives the stimuli prior to training and on the order of presentation of stimuli.

Forty-eight adult Long-Evans male rats were tested
following castration for male and female sex behavior.
Following baseline test Ss received 200 mug injections of estradiol daily except on days of female tests when
20 mug of progesterone were given. Tests for male and female
behavior were alternated every third day. Significant
increases in mean lordosis and male behavior occurred
following hormone treatment. After hormone tests eight Ss received anterior lesions and five Ss received preoptic lesions. Afer recovery Ss were placed on the same schedule of hormones and tests as for the previous condition. No
significant changes in mean lordosis or male behavior occurred
following either lesion. It was concluded that estrogen is
effective in restoring male behavior and producing female
sex behavior in castrated males. While no significant changes
occurred following the lesions, it was determined that repetition and extension of the work is justified.