Temporal Self-Compression: Behavioral and neural evidence that past and future selves are compressed as they move away from the present

Abstract

Although it is well-known that people feel disconnected from their past and future selves, the underlying mechanism supporting this phenomenon is unknown. To help fill this gap, we considered a basic principle of perception. As objects increase in distance from an observer, they also become logarithmically compressed in perception (i.e., not differentiated from one another), making them hard to distinguish. Here, we report four studies that suggest we may feel disconnected from distant selves, in part, because they are increasingly indiscriminable with temporal distance from the present self. In Studies 1-3, participants made trait ratings across various time points in the past and future. We found that participants compressed their past and future selves, relative to their present self. This effect was preferential to the self and could not be explained by the alternative possibility that individuals simply perceive arbitrary self-change with time irrespective of temporal distance. In Study 4, we tested for neural evidence of temporal self-compression by having participants complete trait ratings across time points while undergoing functional magnetic resonance imaging (fMRI). Representational similarity analysis (RSA) was used to determine if neural self-representations are compressed with temporal distance, as well. We found evidence of temporal self-compression in areas of the default network, including medial prefrontal cortex (MPFC) and posterior cingulate cortex (PCC). Specifically, neural pattern similarity between self-representations was logarithmically compressed with temporal distance. Taken together, these findings reveal a "temporal self-compression" effect, with temporal selves becoming increasingly indiscriminable with distance from the present. Significance StatementFor centuries, great thinkers have struggled to understand why we feel disconnected from our past and future selves. Insight may come from a basic principle of perception: as objects become distant, they also become less discriminable, or compressed. In Studies 1-3, we demonstrate that peoples ratings of their own personality become increasingly less differentiated as they consider more distant past and future selves. In Study 4, we found neural evidence that the brain compresses self-representations with time, as well. When we peer out a window, objects close to us are in clear view whereas distant objects are hard to tell apart. We provide novel evidence that self-perception may operate similarly, with the nuance of distant selves increasingly harder to perceive.