Faster orientation latencies toward native language in two-month-old infants

There is increasing evidence that infants can discriminate native and nonnative speech from an early age. Prosody may be essential to this ability. In this paper, we assess the amount of linguistic information needed by 2-month-old infants to recognize whether or not a sentence belongs to their native language. We conducted a cross-linguistic study of French and American 2-month-old infants, measuring the latency of the first ocular saccade toward a loudspeaker playing short French and English utterances. The results indicated a significant interaction between the infants' nationality and the language of the stimuli. Infants oriented faster to their native language, even when the utterances were short (1.2 s mean). However, eliminating the prosodic organization (scrambled words condition) of the sentences, neutralized the effect. The results confirm that prosody plays a predominant role when young infants process continuous speech, and that short utterances are sufficient to recognize a language as long as prosodic information is present and coherent across the utterance.