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Biomedical subjects

E E Perris

Publications and source records attributed to E E Perris.

4 recordsLinked to original sources
PubMed1991

Object representation guides infants' reaching in the dark.

Infants were presented with two sounding objects of different sizes in light and dark, in which sound cued the object's identity. Reaching behavior was assessed to determine if object size influenced preparation for grasping the object. In both light and dark, infants aligned their hands when contacting the large object compared with the small object, which resulted in a reach with both hands extended for the large object and reach with one hand more extended for the small object. Infants contacted the large object more frequently on the bottom and sides rather than the top, where the sound source was located. Reaching in the dark by 6 1/2-month-olds is not merely directed toward a sound source but rather shows preparation in relation to the object's size. These findings were interpreted as evidence that mental representation of previously seen objects can guide subsequent motor action by 6 1/2-month-old infants.

Attention↗
PubMed1990

Long-term memory for a single infancy experience.

Children's memory of a single infant experience was evaluated. Children in the experimental groups (N = 16 for 2.5-year-olds; N = 8 for 1.5-year-olds) had participated at 6.5 months in a study of auditory localization where they reached in the light and dark for a sounding object. They were reintroduced to the laboratory and the dark procedure they had experienced on that one occasion either 1 or 2 years previously. The first 5 trials were uninstructed; for the remaining 5 trials, children were instructed to find the sounding object. For half of the older group, a potential reminder of the infant procedure was introduced. The original infant rattle was sounded for 3 sec out of reach in the dark one-half hour prior to test trials. Equal numbers of age-matched inexperienced control subjects were also tested. The older children with infant experience reached and grasped the sounding object significantly more overall, and on instructed trials, than age-matched control children. Experienced 2.5-year-olds were also more likely to remain in the testing situation than children in the control group. The reminder facilitated uninstructed performance of the experienced children. Instructions to reach were helpful to all subjects. We conclude that children remembered aspects of a single experience that occurred when they were 6.5 months of age.

Auditory Perception↗
PubMed1989

Stimulus duration and repetition rate influence newborns' head orientation toward sound.

Three experiments evaluated the effects of stimulus duration and repetition rate on newborns' head orientation responses. In Experiment 1, 28 infants turned toward a 20-sec continuous rattle sound but not toward 14- and 500-msec rattle sounds. Signal energy as a possible explanation for the infants' difficulty orienting toward brief sounds was explored in Experiment 2. Twenty neonates did not turn toward a single 90 dB, 14-msec rattle sound, although a longer duration (10 sec) sound containing less energy (70 dB) did elicit reliable head orientation. In Experiment 3, 16 neonates heard trains of repeated 14-msec rattle sounds (2/sec, 1.3/sec, and 1/sec) lasting 10 sec as well as a 10-sec continuous rattle sound. They turned toward the most rapidly repeating brief sound and the continuous one, while the slowly repeating sounds elicited little head movement in any direction. These results suggest that newborns' head orientation is selectively deficient for brief sounds, that the difficulty does not result from lessened energy in the brief sounds, and that the efficacy of repeated brief sounds depends upon their repetition rates.

Analysis of Variance↗