Emotional versus nonemotional lexical perception in patients with right and left brain damage

Objective: This study examined lexical emotional perception in patients with unilateral brain damage. Background: Hypotheses pertaining to laterality and emotion were tested. More specifically, we were interested in whether the right hemisphere is dominant for verbally-presented emotion. In addition, we examined whether emotional content improves the performance of patients with left brain damage (LBD) and language deficits. Method: Subjects were 11 patients with right brain damage (RBD), 10 patients with LBD, and 15 normal control adults. The subject groups did not differ significantly on demographic or basic cognitive variables; the patient groups were similar on neurologic variables. Parallel emotional experimental and nonemotional control tasks included word identification (or recognition), sentence identification, and word discrimination. There were eight emotional categories (e.g., happiness) and eight nonemotional categories (e.g., vision). Results: A significant interaction among Group, Condition, and Task revealed that patients with RBD were significantly impaired relative to patients with LBD and normals within the emotional condition, particularly for the identification tasks. Furthermore, the performance of patients with LBD and language deficits was improved by emotional content for the sentence identification task. Conclusions: These findings suggest that the right hemisphere has a unique contribution in the identification of lexical emotional stimuli. Implications for rehabilitation of patients with LBD and language deficits and patients with RBD by means of emotion-based strategies an discussed.