Pulsed ultrasound was used to study tongue movements in the speech of children from 3 to 11 years of age. Speech data attained were characteristic of systems that can be described by second-order differential equations. Relationships observed in these systems may indicate that speech control involves tonic and phasic muscle inputs. (Author/RH)

Examines whether kindergarteners, second-graders, fourth-graders, and adults can extract relative weight information from observing collisions and lifting events, and if they can judge whether or not collisions are momentum-conserving. Subjects saw either videotapes of events or sequences of static images; younger children appeared to be…