Elucidating the neural mechanisms underlying cognitive processes related to self has been a promising approach to enhancing the scientific knowledge of mental health and mental disorders. However, relevant data from functional neuroimaging studies have not yet converged. The multi-layered model of self-processing proposed here reconciles these seemingly controversial findings by assuming there are three layers of self, including the physical self, interpersonal relationships, and social value. A schema that associates the representations of output and feedback in different cortical networks was conceptualized for each layer of self. The concepts of self-related cognition and mental disorders may be reconstructed based on this three-layer structure. The brain regions that accommodate the proposed schema are assumed to respond during the detection of error relative to a prediction; consequently, this neural response may be used for diagnosis and evaluation of mental disorders and health.
TopBackground
There is some neuropsychological evidence for the neural underpinnings of self-processing. Several cases of brain-damaged patients have reported abnormal self-processing, such as the out-of-body experience (Blanke, Landis, Spinelli, & Seeck, 2004), an impaired self-attribution of one’s own actions (Spence, 2002), and an impaired self-face recognition (Gallois, Ovelacq, Hautecoeur, & Dereux, 1988). In addition, an impaired visual self-recognition has been observed in patients with severe dementia (Breen, Caine, & Coltheart, 2001).
The cognitive neuroscience approach to self-cognition was initially driven by the assumption that the self is a unitary construct. Many evolutionary psychologists have noted visual self-recognition as the representation of a special social ability present only in socially evolved brains. The ability of self-recognition through a mirror-reflection has been demonstrated in a limited species of animals that have large brains relative to the size of their body (Gallup, 1982; Marino, 2002; Shoshani, Kupsky, & Marchant, 2006). These animals show complex social behaviors that require empathy and perspective taking (Gallup, 1982; Marino, 2002; Plotnik, de Waal, & Reiss, 2006). In human infants, self-directed behavior in front of a mirror typically appears in the second year of life, and it coincides with the emergence of the empathic behavior (Gallup, 1982; Zahn-Waxler, Radke-Yarrow, Wagner, & Chapman, 1992).