Figure 2.
Heart rate changes in infants from 3 to 6 months during looks toward complex audiovisual stimuli (Richards & Gibson, 1997). The data are plotted as changes in interbeat-intervals (IBI change), with longer IBIs reflecting a deceleration of heart rate. The lines are separated by look lengths (1: 0–5s; 2: 5–10s; 3: 10–20s; 4: 20–40s 5: > 40s; 6: 100–150 and 200 s).