Habitutation Technique

Infant sucks on (non-nutritive) nipple.

Baseline high amplitude sucking rate is determined during a 1-minute silent period.

Following baseline period, presentation of sound stimulus is made contingent on rate of high-amplitude sucking:

Criterion sucks result in presentation of one speech stimulus.

When infant habituates to stimulus (according to some pre-determined decrement in sucking rate), stimulus changes (post-shift period) for infants in experimental condition.

Differences in sucking rate in the post-shift period for infants in the experimental vs. control conditions is used to assess infant's sensitivity to stimulus differences.