Fear recognition deficits after focal brain damage - A cautionary note

Objective: To test the hypothesis that fear recognition deficits in neurolo gic patients reflect damage to an emotion-specific neural network. Backgrou nd: Previous studies have suggested that the perception of fear in facial e xpressions is mediated by a specialized neural system that includes the amy gdala and certain posterior right-hemisphere cortical legions. However, the neuropsychological findings in patients with amygdala damage are inconclus ive, and the contribution of distinct cortical regions to fear perception h as only been examined in one study. Methods: We studied the recognition of six basic facial expressions by asking subjects to match-these emotions wit h the appropriate verbal labels. Results: Both normal control subjects (n = 80) and patients with focal brain damage (n = 63) performed significantly worse in recognizing fear than in recognizing any other facial emotion, wit h errors consisting primarily of mistaking fear for surprise. Although pati ents were impaired relative to control subjects in recognizing fear, we cou ld not obtain convincing evidence that left, right, or bilateral lesions we re associated with disproportionate impairments of fear perception once we adjusted for differences in overall recognition performance for the other f ive facial emotion categories. The proposed special role of the amygdala an d posterior right-hemisphere cortical regions in fear perception was also n ot supported. Conclusions: Fear recognition deficits in neurologic patients may be attributable to task difficulty factors rather than damage to putat ive neural systems dedicated to fear perception.