The neural bases and bodily correlates of Mental Time Travel

Time is abstract, yet we navigate it through Mental Time Travel (MTT)—the capacity to project ourselves mentally into the past and the future. Beyond episodic recollection, MTT relies on non-episodic components such as semantic knowledge, schemas, and embodied processes (e.g., visuospatial attention and bodily self-representations). At the neural level, MTT depends on interactions among brain structures, with a crucial hub in the ventromedial prefrontal cortex (vmPFC). In the first study, we examined the vmPFC’s contribution to accessing personal semantic knowledge and how this supports event construction. Patients with vmPFC lesions showed difficulties in activating personal semantic knowledge and exhibited an atypical pattern of event construction, characterized by “backward” transitions from episodic to semantic levels of representation. In the second study, participants placed typical life events along a timeline and estimated the likelihood of experiencing similar events when projecting to different past and future moments. vmPFC patients systematically anticipated the typical occurrence of life events, both on the timeline and during MTT, indicating reduced activation of temporal schemata and reduced temporal orientation during MTT. The third study investigated how perceptual representations of the body influence self-concept across time. After inducing ownership of an aged version of one’s face (Enfacement Illusion), participants reported greater perceived similarity between present and future selves, physically and conceptually. Finally, the fourth study demonstrated that bodily (gaze direction) and non-bodily (optokinetic stimulation) cues capable of modulating visuospatial attention differentially affect two aspects of temporal cognition: MTT and temporal estimation. Specifically, only gaze direction facilitated temporal self-projection in a spatially specific manner, whereas both manipulations similarly modulated the scalar representation of temporal estimation. Overall, these studies provide converging evidence for a view of MTT as a flexible, multilayered cognitive ability integrating episodic, semantic, and embodied processes, which together enable a coherent and embodied navigation of personal time.