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Observations that RHD patients are autonomically
hypoaroused in response to affective scenes (relative to NHD
and LHD patients) have been interpreted as support for a
dominant role of the right hemisphere in emotional arousal.
However, this interpretation is not without question given
that such studies have generally measured autonomic
responsivity only in response to neutral and unpleasant
scenes (Meadows & Kaplan, 1992; Zoccolatti et al., 1982) or
situations (Heilman et al., 1978). Pleasant scenes or
stimulus materials have not been used in such studies and it
remains unknown whether stroke of the right hemisphere
equally attenuate autonomic reactivity to pleasant scenes.
In and of itself, the current existing data that RHD stroke
patients are hypoaroused to negative-affective scenes are
equally consistent with the bivalent as well as the global
right hemisphere model. Of relevance, Morris et al. (1991)
recently reported valence-specific hypoarousal in a patient
following a right temporal lobectomy. Skin conductance
responses were obtained to unpleasant (mutilations),
pleasant (attractive nudes), and neutral (breadbaskets)
slides. This patient showed abnormally reduced SCR to
unpleasant but normal SCR to pleasant and neutral slides, a
pattern of findings that is consistent with a bivalent
model. Had only unpleasant scenes been used in this study
one would not be able to logically distinguish between the
bivalent and global right hemisphere model. For this