Hostility and Cardiovascular Regulation: An Investigation of Lateralized Pre-Motor Functions

Behavioral and physiological correlates of hostility, such as cardiovascular lability and increased risk of cardiovascular disease, are vital when considering the possible health risks associated with high levels of hostility (Henry & Meehan, 1981; Matthew & Haynes, 1986; Johnson, 1990; Heller, 1993; Heilman, Bowers, & Valenstein, 1993; Demaree & Harrison, 1997; Demaree Harrison, & Rhodes, 2000; and Shenal & Harrison, 2001). By examining this issue through a functional cerebral systems approach, one is better able to conceptualize changes that occur when men with extreme hostility levels (e.g. high and low) carry out emotional regulation tasks. High and low hostile groups have been shown to differ in their auditory, visual, somatosensory, and motor processes. Moreover, they differ in lateralized cerebral functions within these modalities where high hostiles have shown a right cerebral/ negative affective bias while low hostiles have shown a left cerebral/ positive affective bias in perception and in motor functions to stress. Right cerebral activation in high hostiles has occurred with heightened reactivity and persistence in sympathetic tone and with cardiovascular changes in heart rate, blood pressure, and Galvanic skin response. In the present experiment, this systematic line of research (Harrison & Gorelczenko, 1990; Herridge & Harrison. 1996; Demaree & Harrison, 1997; Herridge, Harrison, & Demaree, 1997; Demaree, Higgins, Williamson, and Harrison, 2002; Williamson & Harrison, in press) was extended to the investigation of the premotor frontal eye fields using rapid directional eye movements toward the contralateral hemisphere. It was predicted that high hostiles would evidence right frontal deficits in lateral eye movements (LEM) resulting in decreased LEM toward and within the left hemispace. Moreover, concurrent processing of lateralized eye movements and regulation over cardiovascular responding was predicted to yield sympathetic dysregulation on leftward LEM (lLEM) and potentially parasympathetic dysregulation on rightward LEM (rLEM). Leftward LEM appeared to result in more fatigue effects than rightward LEM. However, the primary behavioral hypothesis was not supported. Moreover, the directional relationship predicted between left side LEM and sympathetic tone was not found. Instead, LEM in either direction occurred with corresponding reduction in sympathetic blood pressure. Diametrically opposite results were found for the non- directional cold pressor stressor. High hostiles were found to be more reactive in their cardiovascular response to stress than the low hostiles.