When directly manipulating 3D objects in an immersive environment we cannot normally achieve the accuracy and control that we have in the real world. This reduced accuracy stems from hand instability. We present PRISM, which dynamically adjusts the C/D ratio between the hand and the controlled object to provide increased control when moving slowly and direct, unconstrained interaction when moving rapidly. We describe PRISM object translation and rotation and present user studies demonstrating their effectiveness. In addition, we describe a PRISM-enhanced version of ray casting which is shown to increase the speed and accuracy of object selection.

Wide individual differences in early word production characterize children learning the same language, but the role of specific adult input in this interchild variability is unknown. Sampling the speech of American, French, and Swedish mothers (5 in each language group) to their 1-year-old children, this study analyzed the distribution of consonantal categories, word length, and final consonants in running speech, content words, initial consonant of content words, and target words (adult models of words attempted by the children) as well as the children's own early words (from age 9 months to about 18 months). Variability is greater in child words than adult speech, and individual mother-child dyads show no evidence of specific maternal influence on the phonetics of the child's speech.

Appetitive and aversive experiences influence whether odors elicit precopulatory behavior from male rodents. A role for aversive experience in odor-elicited reproductive behaviors had been demonstrated for hamsters and rats, but similar work on house mice had not been performed. Four experiments examined whether lithium chloride (LiCl) aversive conditioning would alter two precopulatory behaviors (ultrasonic vocalizations and olfactory preference) that male house mice normally exhibit to female urine. Lithium chloride was used to aversively condition male house mice to either female urine odor, female urine in drinking water, the female herself, or a novel odor. Independent tests of taste aversion establishment were also conducted. In these experiments, LiCl aversive conditioning produced robust taste aversions to water adulterated with either female urine or a novel odorant/tastant (isoamylacetate), but only transitory decrements in odor-elicited, male-typical precopulatory behaviors. We conclude that aversive conditioning is unlikely to be a significant factor affecting male mouse precopulatory behavior.