Self-awareness and the left hemisphere: the dark side of selectively reviewing the literature.

and were modestly acknowledged by the team in Platek et al. (2004b). In the target article, Keenan et al. (2005) present their latest version of the hypothesis, which in my view carries over the exact same problems identified in the past. In this commentary I examine conceptual and empirical difficulties pertaining to the notion of right hemispheric superiority for self-related processes. I will suggest that two main misconceptions lie at the heart of the controversy. (1) At a conceptual level, one cannot equate either self-recognition or Theory-of-Mind (TOM) abilities with genuine self-awareness. (2) At an empirical level, the review of literature presented by Keenan et al. tends to favor studies that support their hypothesis. In actuality, quite a few brain-imaging experiments show bilateral and left hemisphere activity during self and other judgment tasks. SELF-RECOGNITION AND SELF-AWARENESS " Self-awareness involves being aware of one's own thoughts, or mental state. It includes having the ability to reflect on one's own cognitions. Further, self-awareness includes the ability to think about oneself as an entity in the third person, allowing for imagining oneself in the future or in the past " (p. 695). After presenting Gallup's work on self-recognition in primates (e.g., Gallup, 1970; Gallup et al., 2002), and related research, Keenan et al. ask: " Does self-recognition equal self-awareness? " (p. 696). Their answer is a confident " yes " , which lead them to suggest that " ... the self-face may be an ideal stimulus to begin the investigations of higher-order consciousness and the brain " (p. 697). The group then reviews several studies that have examined selective brain activation during self-face recognition tasks as well as other forms of self-recognition (e.g., one's voice), and neuropsychological reports of right hemisphere damage. The body of research presented in Keenan et al.'s paper largely supports right hemisphere superiority for self-recognition, which motivates the conclusion that " ... along numerous dimensions, the right hemisphere appears dominant for self-awareness " (p. 700). The overall rationale put forward by Keenan and his collaborators is simple and elegant: (1) self-recognition equals self-awareness; (2) self-recognition is correlated with activity in the right hemisphere, especially the prefrontal lobe; (3) thus, self-awareness per se is also linked to right hemisphere activity. I hope to show that the first two statements (1) and (2) are most likely inaccurate, which obviously will make statement (3) incorrect. The proposition that self-recognition is equivalent to …