Early temperamental fearfulness and the developmental trajectory of error-related brain activity.

The error-related negativity (ERN) is a negative deflection in the event-related potential waveform that occurs when an individual makes a mistake, and an increased ERN has been proposed as a biomarker for anxiety. However, previous work suggests that fearful children are characterized by a smaller ERN. We have proposed that this may reflect the changing phenomenology of anxiety across development. In the current study, we investigate this possibility using a longitudinal within-subject design. In 271 children, we completed observational measures of fear when the children were 3 years old, and then measured the ERN when the children were 6 and 9 years old. Fearful children were characterized by a decreased ERN when they were 6-year-old; by age 9, the same children who were fearful at age 3 had increased ERNs-a pattern that closely resembles that of anxious adolescents and adults.