Nhận biết (M1)

Lullabies are characterized by their lower melodic complexity and other features that are believed to have a calming effect on infants. Some critics, however, have claimed that the relaxation effect of these songs is more likely due to the infants' prior familiarity with a particular lullaby, as infants tend to be soothed by familiar sounds in general. To test this hypothesis, Constance M. Bainbridge and colleagues played both a lullaby sung in the Border Kuna language and a non-lullaby sung in the Scottish Gaelic language to a group of infants unfamiliar with either song. Because a reduced heart rate is considered a measure of relaxation, the researchers monitored the infants' heart rates as the songs played.

Which finding, if true, would most directly weaken the underlined claim?

• A.

  Both the song in Border Kuna and the song in Scottish Gaelic were sung by a person whose voice was familiar to the infants.

• B.

  The heart rates of the infants in the study were more irregular during the lullabies than during non-lullabies.

• C.

  Parents of infants in the study chose the lullaby over the non-lullaby when asked which song they would use to calm their child.

• D.

  The heart rate of infants decreased substantially more during the lullaby than during the non-lullaby.