From memory to prospection: what are the overlapping and the distinct components between remembering and imagining?

Abstract

Reflecting on past events and reflecting on future events are two fundamentally different processes, each traveling in the opposite direction of the other through conceptual time. But what we are able to imagine seems to be constrained by what we have previously experienced, suggesting a close link between memory and prospection. Recent theories suggest that recalling the past lies at the core of imagining and planning for the future. The existence of this link is supported by evidence gathered from neuroimaging, lesion, and developmental studies. Yet it is not clear exactly how the novel episodes people construct in their sense of the future develop out of their historical memories. There must be intermediary processes that utilize memory as a basis on which to generate future oriented thinking. Here, we review studies on goal-directed processing, associative learning, cognitive control, and creativity and link them with research on prospection. We suggest that memory cooperates with additional functions like goal-directed learning to construct and simulate novel events, especially self-referential events. The coupling between memory-related hippocampus and other brain regions may underlie such memory-based prospection. Abnormalities in this constructive process may contribute to mental disorders such as schizophrenia.

Keywords: associative learning; cognitive control; creativity; emotion; hippocampus; memory; prospection; self.

FIGURE 1

A typical cue-word task for probing mental conceptions of past and future events. (A) At the beginning of each trial, an event cue word is presented on a computer screen, whereupon participants are instructed to describe in detail either what they may remember of a specific episode in the past or to imagine a plausible episode in the future. The orienting cue (either to remember or imagine) is shown above the event cue. Following the description stage in which they provide their descriptions as requested, participants rate each episode’s phenomenology (such as its vividness) on a 5-point Likert scale. (B) The subsequent panel in Figure 1 shows primary cue types and corresponding instructions from Hassabis et al. (2007b)), Sharot et al. (2007) and Szpunar et al. (2007). For example, emotional cues contain positive and negative words, and participants are instructed to imagine or remember an emotional event according to the given word and orienting cue.

FIGURE 2

Examples of memory and prospection concerning visual–spatial context processing. Once we trace the memory or think about the future, a visual–spatial scene appears in our mind. Constructions of memory and prospection always reflect numerous similarities in scene construction.

FIGURE 3

Distinct processes of prospection. In order to plan a birthday party, first we should: (1) set a specific goal, such as where to hold the party and who to invite; (2) our planning might next rely heavily on cognitive control to focus on current goal-of holding a birthday party, without regard to other considerations; (3) and eventually in order to generate a more specific plan you might associate with past experiences to better plan your party. An example might go that, having learned that apple pie was more popular than banana pie at your last birthday party, you are now subsequently more likely to prepare apple pie this time around; (4) further to actualize and promote your party, you may also need creativity thinking to facilitate designing something unique.

FIGURE 4

Interactionist model of memory and prospection. The overlap and distinct components between memory and prospection are presented in the model; the regions in the parentheses represent corresponding activated regions.