Lack of visual avoidance in patients with unilateral brain damage: New perspectives from old, unexpected, neglected data

The present commentary revisits some old data, concerning the same kind of visual avoidance behaviors described by Otero and Levenson's (2019) in their target paper and proposes a new perspective on the neural underpinnings of such behaviors. A lack of visual avoidance in response to a shocking film clip had been unexpectedly observed during a study of emotional expression in patients with unilateral brain damage (Mammucari et al., 1988). This lack of visual avoidance in subjects with right hemisphere brain lesions was attributed to the emotional indifference of these patients. These results could be complementary to those obtained by Otero and Levenson (2019) for two main reasons: (1) they concerned the inter-hemispheric, rather than the intra-hemispheric organization of emotional functions; (2) they could be replicated in FTD patients. Atrophy is, in fact, often asymmetrical in these subjects and several investigations have recently shown that emotional disorders can be on the foreground when atrophy prevails in the right frontal or temporal lobes. The present commentary suggests that a fruitful integration is possible between these two previously independent lines of neuropsychological research.