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ERIC Number: ED139530
Record Type: Non-Journal
Publication Date: 1977-Mar
Reference Count: N/A
Cerebral Asymmetry in Infants.
Vargha-Khadem, Faraneh; Corballis, Michael C.
This paper describes two experiments conducted to replicate the reported findings (Entus, 1975) that infants demonstrate a right ear advantage in the perception of dichotically presented syllables. Using the non-nutritive sucking paradigm, 48 infants 1-3 months of age were presented with verbal stimuli contingent upon criterion level sucking. Following habituation to a stimulus pair, the sound was changed in one ear and the rate of recovery in criterion sucking was recorded. After a short break, the same procedure was repeated with the shift in the stimulus pair occurring in the opposite ear. In both replication attempts, stimulus material, response criteria and equipment involved in recording response measures were identical to those used by Entus. However, the following control measures were introduced: (1) an adjustable mechanical arm to hold the nipple-transducer; (2) a double blind procedure, rendering the experimenter blind to the order of stimulus combinations; (3) a divider screen, separating the experimenter from the subject in order to eliminate possible biasing interactions; (4) the level of criterion sucking was readjusted and reduced (Experiment 1) in order to ensure conditioning of the sucking response. Analysis of variance on the recovery scores was performed to determine the effects of ears, minutes, sex and order of stimulus change. In both experiments there were no significant differences in the recovery scores between ears. These results are discussed in terms of the possible effects of experimenter bias and lack of adequate controls that could have contributed to the findings reported by Entus. (Author/MS)
Publication Type: Speeches/Meeting Papers
Education Level: N/A
Sponsor: National Research Council of Canada, Ottawa (Ontario).; McGill Univ., Montreal (Quebec).
Authoring Institution: N/A