Dopamine activation in Neuroticism as measured by spontaneous eye blink rate

Personality dimensions have been associated with different psychobiological systems. However, no agreement exists in literature on a specific role of a single neurotransmitter for each of the dimensions investigated. We studied the relationship of Neuroticism, Extraversion and Psychoticism as assessed by Eysenck Personality Inventory (EPI) with spontaneous eye blink rate (BR), a non-invasive measure of central dopamine activity. A total of sixty-three healthy subjects (40 females, 23 males, mean age 24.2 ± 3.9) were studied. Spontaneous blink rate and time of blink suppression were assessed by EOG measurement.Levels of Extraversion and Neuroticism were inversely correlated. In contrast with previous findings, a significant correlation between blink rate measures and Neuroticism was found. No significant correlation between blink measures and either Extraversion, or Psychoticism were found. The results appear consistent with a lower threshold for activation in neuroticism as suggested by Eysenck's original model.

► We examine Eysenck's personality dimensions and blink rate. ► Blink rate shows a significant positive correlation with Neuroticism. ► Blink rate is a measure of dopamine activation and increased arousal. ► Subjects with high Neuroticism show increased activation. ► Blink rate could identify psychobiological vulnerability to major psychiatric illness.