Brown J W, Leavitt L A, Graham F K
Dev Psychobiol. 1977 May;10(3):255-66. doi: 10.1002/dev.420100309.
Response to 5-sec, 75-dB complex sounds was studied in groups of 24 infants each at 6 and 9 weeks of age. Under conditions appropriate for eliciting orienting, no significant cardiac response appeared at 6 weeks, but a significantly decelerative response did appear at 9weeks. Measurement of noncardiac responses suggested that sucking suppression is also a component of orienting to sound, that the status of eye-opening is equivocal, and that previously reported eye-movement responses are probably a component of startle. We concluded that age changes in orienting may occur in young infants, even when state is controlled, and that the probability of orienting varies with the kind of stimuli employed.
对每组24名6周龄和9周龄婴儿进行了对5秒、75分贝复合声音的反应研究。在适合引发定向反应的条件下，6周龄时未出现明显的心脏反应，但9周龄时出现了明显的减速反应。对非心脏反应的测量表明，吸吮抑制也是对声音定向的一个组成部分，睁眼状态不明确，先前报道的眼动反应可能是惊吓的一个组成部分。我们得出结论，即使在控制状态的情况下，婴儿早期的定向反应也可能发生年龄变化，并且定向反应的可能性随所采用的刺激类型而变化。
