Order-dependent timing of unimodal and multimodal stimulation affects prenatal auditory learning in bobwhite quail embryos

This study examined the relationship between unimodal and multimodal sensor y stimulation and their effects on prenatal auditory learning in bobwhite q uail embryos. Embryos exposed to a maternal call in the 24 hr prior to hatc hing (unimodal condition) significantly preferred this familiar call over a n unfamiliar call in postnatal testing, but failed to demonstrate this pref erence when the maternal call was presented concurrently with non-synchroni zed patterned light (multimodal condition). To further explore this interfe rence effect, we provided one group of embryos concurrent exposure to a mat ernal call and patterned light for 12 hr followed by 12 hr exposure to the call alone (multimodal-->unimodal call). This group failed to prefer the fa miliar call during postnatal testing. In contrast, reversing the order of p resentation during prenatal exposure (unimodal call-->multimodal) led a sec ond group of subjects to significantly prefer the familiar call, suggesting that the order-dependent timing of sensory stimulation can significantly i mpact prenatal auditory learning. Experiment 3 examined the influence of mo dality versus timing of sensory stimulation on prenatal auditory learning b y providing three groups of embryos with exposure to a maternal call during the 12 hr prior to hatching and by varying the duration of visual stimulat ion. Results indicate that 12 hr unimodal exposure to patterned light does not support prenatal auditory learning when it is followed by 12 hr exposur e to multimodal stimulation (light-->multimodal), but can facilitate prenat al auditory learning when it is followed by unimodal exposure to the call a lone (light-->call). Results are discussed in terms of intersensory relatio nships during perinatal development. (C) 2001 John Wiley & Sons, Inc.