Premium
Variation in motor activity on different time scales and responsiveness to oral stimulation in the rat fetus
Author(s) -
MacLennan Benjamin D.,
Smotherman William P.,
Robertson Steven S.
Publication year - 1998
Publication title -
developmental psychobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 93
eISSN - 1098-2302
pISSN - 0012-1630
DOI - 10.1002/(sici)1098-2302(199809)33:2<125::aid-dev3>3.0.co;2-l
Subject(s) - stimulus (psychology) , fetus , motor activity , psychology , stimulation , presentation (obstetrics) , developmental psychology , neuroscience , medicine , biology , obstetrics , pregnancy , cognitive psychology , genetics
Abstract The near‐term rat fetus exhibits brief oral grasp responses to discrete presentations of an artificial nipple. In the present experiment, an artificial nipple was presented to individual fetal subjects 10 times. Five of the presentations were timed to occur when spontaneous fetal motor activity was low and five while activity was high, as determined by the baseline activity for the individual fetus. The likelihood of responding to the artificial nipple was increased when the fetus was relatively inactive at the moment of stimulus presentation. Furthermore, stimulus presentations that resulted in oral grasping of the artificial nipple were associated with greater point‐to‐point variability (2‐s intervals) in motor activity during the 30‐s period preceding the presentation of the artificial nipple. This pattern of results indicates that the recent history of general motor activity as well as the level of activity at the instant of stimulus presentation may contribute to variation in responding to biologically relevant stimuli early in development. © 1998 John Wiley & Sons, Inc. Dev Psychobiol 33: 125–131, 1998