[Note: You may find this post less confusing if you first read “Of Time Machines and Memory, Part 1.” Among other things, I explain the difference between author Charles Yu’s How to Live Safely in a Science Fictional Universe (aka, the novel) and character Charles Yu’s How to Live Safely in a Science Fictional Universe (aka, the handbook).]1

From the handbook’s entry on the TM-31 Recreational Time Travel Device, which is the means by which people in Minor Universe 31 travel through time:

One notable quirk of the word recreational in the product’s name, which can be read either of two ways, with a hyphen or without, which some have suspected to be an implicit acknowledgement of the fact that “recreational” use of the machine is also, in a sense, “re-creational” use as well.

This idea is consistent with the current understanding of the neuronal mechanism of human memory, i.e., every time a user recalls a memory, he is not only remembering it, but also, from an electrochemical perspective, literally re-creating the experience as well.

Memory and imagination, recreation and creation, both seem to be intimately tied. Consider, for instance, these three passages, the first two from Mary Carruthers The Craft of Thought (( The Craft of Thought: Meditation, Rhetoric, and the Making of Images, 400 – 1200. Cambridge Studies in Medieval Literature 34. Cambridge: Cambridge UP, 1998. )) :

The emphasis upon the need for human beings to ‘see’ their thoughts in their mind as organized schemata of images, or ‘pictures,’ and then to use them for further thinking, is a striking and continuous feature of medieval monastic rhetoric, with significant interest even for our own contemporary understanding of the role of images and thinking. (Craft of Thought 3)


Medieval memoria thus includes, in our terms, “creative thought,” but not thoughts created “out of nothing.” It built upon remembered structures “located” in one’s mind as patters, edifices, grids, and — most basically — association-fabricated networks of “bits” in one’s memory that must be “gathered” into an idea.  (Craft of Thought 23)

and the third from Mark Johnson’s “The Imaginative Basis of Meaning and Cognition”2 :

According to the view I am espousing, we must understand imaginative activity as including all sensory modalities, motor programs, and even abstract acts of cognition such as the drawing of inferences. In this very broad sense, imaginative activity is the means by which an organism constructs an ordering of its perceptions, motor skills, and reflective acts, as it seeks to accommodate itself to its environment. Imagination, so understood, thus includes the full range of organizing activities, from the forming of images (in different sensory modalities), to the execution of motor programs, to the manipulation of abstract representations, and even to the creation of novel orderings. (79)

All of this is quite interesting in light of research which finds that scene construction is a shared process common to both episodic memory and the creation of fictional experiences as reported by Demis Hassabis, Dharshan Kumaran, and Eleanor A. Maguire in “Using Imagination to Understand the Neural Basis of Episodic Memory”3:

Functional MRI (fMRI) studies investigating the neural basis of episodic memory recall, and the related task of thinking about plausible personal future events, have revealed a consistent network of associated brain regions. […]. By using previously imagined fictitious experiences as a comparison for episodic memories, we identified the neural basis of a key process engaged in common, namely scene construction, involving the generation, maintenance and visualization of complex spatial contexts. […]. We conclude that scene construction constitutes a common process underlying episodic memory and imagination of fictitious experiences, and suggest it may partially account for the similar brain networks implicated in navigation, episodic future thinking, and the default mode.  [Read full abstract.]

All of this seems to suggest that the active creation of one’s own mnemonic images is an important mnemonic practice, something we’ve already known. In other words, this is really just a post connecting contemporary cognitive research to long-established mnemonic practices.

  1. Note: The first quote of this post has been sitting around for a few weeks in draft form. At one point, I thought I had something to say about it, but I only have the vaguest notion of what it might have been. As that’s the case, I’m releasing this to the wild, juxtaposed with a few additional quotes in the hopes that something will eventually emerge. []
  2.  Images of Memory: On Remembering and Representation. Ed. Susanne Küchler and Walter Melion. Washington: Smithsonian Institution Press, 1991. 74-86  []
  3. The Journal of Neuroscience, 26 December 2007, 27(52): 14365-14374 []