The Effects of Vestibular-Proprioceptive Stimulation on Motor Maturation and Response to Challenge in Rhesus Monkey Infants

Abstract

This study investigated whether nursery/peer-reared rhesus monkey (Macaca mulatto) infants provided with extra vestibular-proprioceptive stimulation would differ from those reared without such supplementary stimulation on various developmental outcome measures. Fifteen infants were reared under identical conditions with the exception that seven were reared with terry cloth-covered surrogates and terry cloth-covered, water-filled plastic pillows that moved in response to the infants while eight were reared with stationary terry cloth-covered surrogates and terry cloth blankets. All infants were tested throughout the first month of life. Tests were based on widely used human-infant tests designed to measure temperamental, interactive, sensory, and motor characteristics and capabilities. Infants were also tested at 8 months of age on an adaptation of the Bayley Scales of Infant Development. In addition, eight infants (four from each condition) were behaviorally tested for home cage behaviors and responsivity to conditions of unfamiliar events and situations. Results indicated that infants reared with vestibular-proprioceptive stimulation achieved higher scores on the motor subtest from the 8-month assessment, as well as a more favorable response to unfamiliar events and situations.