درون اندیشی و کانون موقت ذهن سرگردان

Current accounts suggest that self-referential thought serves a pivotal function in the human ability to simulate the future during mind-wandering. Using experience sampling, this hypothesis was tested in two studies that explored the extent to which self-reflection impacts both retrospection and prospection during mind-wandering. Study 1 demonstrated that a brief period of self-reflection yielded a prospective bias during mind-wandering such that participants’ engaged more frequently in spontaneous future than past thought. In Study 2, individual differences in the strength of self-referential thought — as indexed by the memorial advantage for self rather than other-encoded items — was shown to vary with future thinking during mind-wandering. Together these results confirm that self-reflection is a core component of future thinking during mind-wandering and provide novel evidence that a key function of the autobiographical memory system may be to mentally simulate events in the future.

In the bestselling novel TheTime Traveler’s Wife ( Niffenberg, 2003), the male protagonist — Henry DeTamble — has a genetic disorder that causes him to travel physically through time to periods of the past or future with personal significance (e.g., the childhood home of his wife). While the laws of physics currently prohibit time travel, we are nevertheless able to revisit the past or simulate the future using a quite straightforward ability — imagination. Such prospective thinking involves a constellation of brain regions including the hippocampus and areas of frontal cortex ( Buckner, 2010, Schacter and Addis, 2007b and Schacter et al., 2008) and is adaptive because it permits the imaginer to “pre-experience” situations that have yet to occur and alter subsequent behavior if necessary ( Bar, 2009, Boyer, 2008, Gilbert and Wilson, 2007 and Wheeler et al., 1997). In addition, the ability to locate autobiographical events in their correct temporal context enables a coherent and stable personal identity to be developed ( Tulving, 1985). While past and present events are represented by a combination of perceptual and memorial details, several lines of evidence suggest that the ability to simulate future outcomes is a construction based on previous autobiographical (i.e., personal) knowledge (Buckner, 2010, Gilbert and Wilson, 2007 and Schacter and Addis, 2007a). First, both autobiographical memory and prospection emerge at around the same age (Suddendorf & Busby, 2003). Second, patients with problems remembering events from their personal past also have difficulties in imagining what they are likely to do in the future (e.g., Klein, Rozendal, & Cosmides, 2002). Finally, neuroimaging studies show overlapping brain activation when individuals remember events from the past and imagine experiences that have yet to occur (Addis, Pan, Vu, Laiser, & Schacter, 2009). It is commonly argued that the primary purpose of mental time travel (Suddendorf and Corballis, 1997 and Suddendorf and Corballis, 2007) and indeed the memorial system (e.g. Bar, 2007, Gilbert and Wilson, 2007 and Schacter and Addis, 2007a) is to ensure the continued existence of the organism by using imagination to look forward rather than backwards in time. Consistent with this hypothesis, participants spend significant time engaged in future related thought under laboratory conditions (Smallwood, Nind et al., 2009 and Smallwood, in press) and in daily life (D’Argeambeau, Renaud, & Van der Linden, 2009). If the primary function of the autobiographical memory system is to mentally simulate the future, it is possible that the process of self reflection would be more strongly associated with the engagement of prospective thought during mind-wandering than it would with thoughts of the past. The current set of studies examined two issues regarding the hypothesized role of self-memory in prospective thought. If the self is especially important to thoughts of the future, then making self-memories salient (e.g., by asking participants to answer self-referential autobiographical questions) should increase the frequency that prospective thoughts arise during mind-wandering. To this end, Study 1 required participants to rate whether a set of trait adjectives applied to one of several referents (i.e., self, best friend and the UK prime minister, see Rogers, Kuiper, & Kirker, 1977), thereby creating a task context that varied the applicability of self-reflection (Kelley et al., 2002, Rogers et al., 1977 and Symons and Johnson, 1997). Following this procedure, we examined whether those individuals who engaged in self-reflection reported more future than past-oriented thoughts during periods of spontaneous mind-wandering than those who did not. In Study 2, we considered whether individual differences in the memorial advantage to self-relevant information (known as the self-reference effect (SRE) (Rogers et al., 1977) moderated the emergence of this effect (i.e., larger SRE = greater prospection). In both experiments, experience sampling was used to assess the momentary occurrence of future and past thought du