The effect of temperamental traits on event-related potentials, heart rateand 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 rea ctivity (ER), endurance (EN) and activity (AC)] in mediating event-related potentials and heart rate responses to visual stimuli. 63 right-handed wome n, aged 19-25 years, participated in the study. Pleasant, unpleasant and no nsense words were used to elicit physiological responses. Subjects were req uired to indicate if a probe was a real word or a nonsense word. P300 ERP p eak and peak amplitude in the 350-600-ms latency range (N500) were measured from Fz, Ct and Pz scalp leads. Measures of HR deceleration response and r eaction time (RT) were also obtained. Split plot ANOVAs were performed betw een high and low level groups selected on the basis of FCB-TI scales. The h igh-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-S S one, showed greater P300 peaks on Fz to positive words and on Ct and Pt t o 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 Ct lead s. 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 differenc es in physiological responding are discussed in terms of arousal theory. (C ) 1999 Elsevier Science Ltd. All rights reserved.