Heart rate and fluency performance among high- and low-anxious men following autonomic stress

Given the well-known associations between the right frontal lobe and negative effective states, as well as the involvement of the right posterior region in the modulation of autonomic nervous system arousal, anxiety is thought to be associated with relative right hemisphere activity (or decreased left hemisphere activity). However, recent evidence suggests that the left hemisphere predominantly modulates parasympathetic efferents, while the right hemisphere predominantly modulates sympathetic efferents of the autonomic nervous system. Thus, the left hemisphere should also play a role in anxiety, as anxiety is associated with decreased parasympathetic activity (increased heart rate). In order to investigate this hypothesis, the present experiment examined the influence of a well-known autonomic stressor (cold pressor) on heart rate (HR), and verbal and nonverbal fluency performance. Fifteen high level (HI) anxious and 15 low level (LO) anxious men completed verbal and nonverbal fluency measures after they were asked to place their left hand in ice water for 45 s. HI anxious subjects demonstrated opposing HR patterns during performance of the verbal (increased HR) and nonverbal (decreased HR) fluency tasks following cold pressor stimulation. In addition, HI anxious men generated fewer words per minute on the verbal fluency task than did LO anxious men. Although the data are supportive of functional right hemisphere activity among anxious individuals, the contribution of decreased left hemisphere activity (i.e., reduced parasympathetic activity and diminished verbal fluency performance) is also discussed.