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 differences in facial expressiveness has been found between

 LHD and RHD patients when Ekman's facial action scoring

 system (FACS) has been used (Mammacuri, et al., 1988;

 Caltagirone, et al., 1989).

 Other studies have examined the ability of RHD and LHD

patients to voluntarily pose specific facial expression.

Some investigators have found that RHD patients were more

impaired than LHD patients and NHD controls in their

voluntary expression of facial affect (Borod, Koff, Perlman-

Lorch, & Nicholas, 1986; Borod, & Koff, 1990; Kent, et al.,

1988; Richardson, Bowers, Eyeler, & Heilman, 1992). Other

investigators (Kolb and Taylor, 1990) found that RHD and LHD

patients are equally impaired relative to NHD controls,

whereas others found no differences in expressivity among

these three groups (Caltagirone et al., 1988; Heilman et

al., 1983; Weddell, et al., 1990).

 Borod (submitted) reviewed the literature on facial

expressiveness in unilateral damaged patients. She

concluded that the patients in those studies finding RHD

patients to be more impaired than LHD and normal controls

differed from those in which differences were not found.

Specifically, she noted that the first group was more likely

to be older, male, with cerebrovascular pathology, and a

longer time since disease onset. The second group was more

likely to have tumor pathology. Additionally, subjective

ratings were used in the first group, while FACS and