Skip to main content
. 2006 Apr 17;103(17):6771–6774. doi: 10.1073/pnas.0602027103

Fig. 1.

Fig. 1.

Representative example of the stimuli. (A) Single video frames of facial gestures made during a coo (Left) and a threat (Right) call, shown at the point of maximal mouth opening. (B) Oscillograms (Upper) and spectrograms (Lower) of the coo and threat vocalizations: coo calls are long and tonal; threat calls are short, pulsatile, and noisy.