The effect of temperamental traits on event-related potentials, heart rate and reaction time

The aim of the study was to examine the role of six temperamental traits as measured by the Formal Characteristics of Behavior–Temperament Inventory [briskness (BR), perseveration (PE), sensory sensitivity (SS), emotional reactivity (ER), endurance (EN) and activity (AC)] in mediating event-related potentials and heart rate responses to visual stimuli. 63 right-handed women, aged 19–25 years, participated in the study. Pleasant, unpleasant and nonsense words were used to elicit physiological responses. Subjects were required to indicate if a probe was a real word or a nonsense word. P300 ERP peak and peak amplitude in the 350–600-ms latency range (N500) were measured from Fz, Cz and Pz scalp leads. Measures of HR deceleration response and reaction time (RT) were also obtained. Split plot ANOVAs were performed between high and low level groups selected on the basis of FCB-TI scales. The high-EN group, compared to the low-EN group, produced significantly smaller P300 peaks to all categories of words. The high-SS group, compared to low-SS one, showed greater P300 peaks on Fz to positive words and on Cz and Pz to negative and nonsense words. The high-PE group, compared to low-PE group, showed larger N500 peaks to emotional and nonsense words on Fz and Cz leads. The HR deceleration response was larger in the low-ER and high-EN groups as compared to opposite temperament characteristics. High-SS subjects, as compared to low-SS ones, displayed shorter RT and a greater HR deceleration to positive words. With respect to FCB-TI dimensions, individual differences in physiological responding are discussed in terms of arousal theory.