Expanding the Scientific Study of Self-Experience with Psychedelics
Manesh Girn and Kalina Christoff
Journal of Consciousness Studies, 2018, 25, (11–12), 131–54
The nature of the self has long been a topic of discussion in philosophical and religious contexts, and has recently also garnered significant scientific attention. Although evidence exists to suggest the multifaceted nature of self-experience, the amount of research done on each of its putative components has not been uniform. Whereas selfreflective processing has been studied extensively, non-reflective aspects of self-experience have been the subject of comparatively little empirical research. This discrepancy may be linked to the methodological difficulties in experimentally isolating the latter. Recent work suggests that one potential way to overcome these difficulties is through the experimentally-controlled administration of psychedelic substances that have the ability to reliably alter non-reflective aspects of self-experience. Here, we review what we know so far about the phenomenology of alterations in self-experience that occur as a result of the administration of psychedelics. We also introduce a taxonomy of such alterations in terms that can bridge contemporary cognitive neuroscience and research on psychedelics. We conclude that the scientific understanding of self-experience may be significantly
advanced by expanding experimental paradigms and theoretical accounts to incorporate work with psychedelic substances.
1. Self-Experience and its Scientific Study
The sense of oneself as an agent in the world is one of the most familiar components of the human experience. Despite this subjective familiarity, the scientific construct of ‘the self’ has continually eluded
precise definition and understanding. Following a long history of discussion in philosophical and religious contexts, recent years have seen the emergence of scientific interest in the self in fields such as cognitive psychology and neuroscience (Christoff et al., 2011; Damasio, 1999; Northoff et al., 2006; Qin and Northoff, 2011; Sui and Gu, 2017). This work conceives of the self as a multifaceted construct that can be divided into reflective (the ‘me’) and non-reflective aspects (the ‘I’), and can encompass multiple components, such as self-location, self-ownership, self-agency, and so on (see Table 1). In addition, a number of types of self have been proposed, such as Antonio Damasio’s tripartite model of a ‘proto self’, ‘core self’, and ‘autobiographical self’ (Damasio, 1999), and more scientifically elusive types such as the ‘minimal self’ (Blanke and Metzinger, 2009; Gallagher, 2000).
The interest in decomposing self-experience and understanding its different aspects has, at least in part, been motivated by an appreciation of its clinical importance. Disturbances of self-experience are a primary feature of a number of psychopathologies. Perhaps the most prominent among these is psychosis (Parnas and Handest, 2003). Individuals suffering an acute episode of psychosis can experience a number of self-disturbances, including dysfunctional self-ownership, self-agency, and sense of first-person perspective (ibid.). Disturbances of self-experience are also present in ruminative depression, in which individuals are unable to disengage from an excessive preoccupation with the autobiographical self (particularly its perceived negative aspects) and its associated self-referential mental content (Nolen- Hoeksema, 1991). Another example is the alteration in bodily self-experience that may occur in individuals with anorexia, who can experience notable disparities between actual body properties (e.g. waist size) and body image (Cash and Deagle, 1997).