CHAPTER 1
 REVIEW OF THE LITERATURE

 Introduction

 Patients with unilateral brain damage have been used to

 investigate hemispheric contribution to emotional

 perception, voluntary expression, and to a lesser extent

 "experience" as indirectly assessed through physiologic

 arousal, overt behavior, and verbal report. Although some

 studies have suggested that differences in post-stroke mood

 occur following right hemisphere damage (RHD) and left

 hemisphere damage (LHD), few studies have assessed brief

 emotional experience while measuring psychophysiological and

 behavioral indices of emotion in these patients. Moreover,

 when emotional experience has been studied using

 physiological indices of emotion, patients needed to decode

 emotional stimuli, which may be problematic for some RHD

 patients. Additionally, no study to date has employed

 facial EMG when examining emotional experience in

 unilaterally damaged patients. In the current project,

 stroke patients with left or right hemisphere lesions

 participated in two experiments designed to examine specific

 deficits in pleasant and unpleasant emotional experience as

a function of unilateral brain damage. Both physiological