title: Cardiac change of retarded and nonretarded infants to an auditory signal.
abstract: Five mentally retarded infants and 5 nonretarded infants were presented a tone for 15 trials. Heart-rate change from prestimulus level showed a deceleration on four 1-second intervals for the nonretarded babies and no change for the retarded babies. Comparison of the two groups of infants revealed a difference on five of the 1-second intervals following stimulus onset. When the total heart-rate change scores were examined for each baby, no overlap of the scores was evident for the infants in the nonretarded group with the individual scores of the retarded infants.
mesh_terms: D000161:Acoustic Stimulation; D001288:Attention; D002657:Child Development; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D006339:Heart Rate; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000503:physiopathology* / Q000523:psychology; D008297:Male