Low positive emotionality (PE; e.g., listlessness, anhedonia, and lack
of enthusiasm) has been hypothesized to be a temperamental precursor or
risk factor for depression. The present study sought to evaluate the
validity of this hypothesis by testing whether low PE children have
similar external correlates as individuals with depression. This paper
focused on the external correlate of EEG asymmetry. Previous studies have
reported that individuals at risk for depression exhibited a frontal EEG
asymmetry (greater right than left activity). Others have reported an
association with posterior asymmetries (greater left than right activity).
In the present study, children classified as having low PE at age 3
exhibited an overall asymmetry at age 5–6 with less relative
activity in the right hemisphere. This asymmetry appeared to be largely
due to a difference in the posterior region because children with low PE
exhibited decreased right posterior activity whereas high PE children
exhibited no posterior asymmetry. These findings support the construct
validity of the hypothesis that low PE may be a temperamental precursor or
risk factor for depression.We gratefully
acknowledge Jurgen Kayser's assistance and advice.