Mental models

I think the solution to the boxological view’s problem with imaginary worlds is to acknowledge an additional structural layer in the cognitive architecture: multiple representational models. The quintessential theory of multiple models was advanced by Josef Perner in his book Understanding the Representational Mind – a dense and thorough work on cognitive development. I won’t have the space here to offer a full treatment of his view, nor will I be a Perner purist in my conclusions. What I aim to show is that multiple models can be structurally compatible with the cognitive architecture offered by

boxological accounts and will solve the problem of imagination’s separation into worlds. According to Perner, infants start out with a single updating model of reality that they build up with sensory information over time.135 For a boxological view, this equates to an infant’s belief box. Like such a view, Perner says that the single reality model is updated in the light of new information. Thus, an UpDater mechanism has a place in such model- building. However, Perner argues that the loss of information through such updating makes

an understanding of temporal change impossible for the mind that has just one reality model.136 To see why this is the case, consider an infant looking up out of her crib at her mother standing over her. This visual percept contributes a representation with content like

My mother is here to her reality model. Then her mother walks into the next room, and

the infant looks at her through the bars of her crib. This new visual percept contributes a representation with content such as My mother is over there to her reality model. There is no mechanism, in Perner’s view, to convert the content My mother is here to My mother

was here, it simply gets deleted and replaced.

Thus, to gain an understanding of temporal change, we must develop more than just a single reality model, but multiple reality models for past, present and future. Perner suggests that the emergence of multiple models happens sometime around the age of 1.5 years, based on evidence that children of this age begin to understand means-ends

relationships and temporal change.137 Whether we all once had a single model and at what age we acquired more is not important for our purposes, however; what does matter is how multiple models aid in the full explanation of both understanding temporal change and imagination.

Perner cites some empirical evidence that children before a certain age perform poorly at tasks that require them to reason using knowledge about the past. He suggests that these failures are due to the child having only the one reality model, from which any

representation of the past has been deleted and replaced. Consider what a boxological account might have to say about this. If there is some mechanism that changes belief contents from present (such as My mother is here) to past (My mother was here), then that mechanism appears to only come into operation at a certain age. I think this is no more mysterious than multiple models only emerging at a certain age, until you consider how multiple models could apply to imagination.

It’s at this point that I suggest an extension of Perner’s view. Like many other theorists, Perner engages quite a bit with Leslie’s metarepresentational theory, and thus is explicitly 136 _{Ibid., 47.}

concerned with securing quarantine. According to Perner, “[t]he need for quarantine is served adequately by multiple models representing different situations.”138 _{For both}

temporal models and imaginary models, Perner suggests that ‘markers’ do the quarantining work – a marker of ‘past’ will not only quarantine a representation of the past from beliefs about the present, but it also determines the functional role of the representation. Thus, the representation with the content My mother is here will not influence our behavior if it’s marked ‘past’ as it will if it’s marked ‘present.’ The same story applies for ‘real’ versus ‘pretend’ markers. A representation with Perner’s ‘pretend’ marker is equivalent to an imagining in our terminology.

This does not yet solve our problem of imaginary worlds, because the markers themselves are binary: ‘real’ or ‘pretend’ for Perner, ‘belief’ or ‘imagination’ for us. The markers indicate that the functional role will be different, so what we’re left with is essentially a notational equivalent to the boxological account – a binary separation between what is imagined and what is believed. I suggest that we have a multitude of imaginative models and that quarantine is secured not by markers but by the cognitive architecture itself. In my view, each imaginary world is a model, and each model is quarantined from every other by the action of the inference mechanisms. Stated another way, the boundary of a model is determined by the inferential relationships of the tokened contents.

Representations belong to the same model if and only if they are processed together by the inference mechanisms, including the UpDater. Since my beliefs are not updated relative to my Dune representations, they are not part of the same model. By the same token, since my Lord of the Rings representations are not updated relative to my Dune representations, they are not part of the same model.

At this point one may object that one of our desiderata is to explain how beliefs and imaginings are processed together by inference mechanisms, but I’ve just said that beliefs are separate from imaginings in virtue of being inferentially quarantined. The relation must be asymmetrical, because it appears that imaginings are elaborated by using beliefs, but

beliefs are not elaborated by using imaginings. The explanation is in how imaginative models are built. Just like in boxological views, imaginative models are functionally distinct from beliefs, including how they are formed. Beliefs are not literally a part of imaginative models at any stage; rather, in the formation of some new imaginative models, belief contents are copied and re-tokened in the new model.

This is not a new idea. Note how Skolnick and Bloom describe our imaginative engagement with fictional stories:

Every time we encounter a new fictional story, we create a new world. The default assumption is that this world contains everything that the real world contains. We then modify this representation based on several constraints: what the story tells us explicitly, what we can directly deduce from specific

conventions of the fictional genre, and, most importantly, how similar to the real world the fictional world is described as being.139

In my view, this creation of a new world is a cognitive feature of imaginative model- building. Imaginative models are initially created by copying and re-tokening the content of another model. However, it does not have to be a belief model. Consider the case of fan fiction. When I read a Harry Potter fan fiction in which Draco Malfoy is secretly working for Sirius Black, I neither modify my existing Harry Potter model and muddle it with non- canon representations, nor do I begin my imaginative engagement with a copy of my belief model sans any Harry Potter content. Rather, I copy the content of my Harry Potter model and re-token it into a new model, which I then update relative to what I read in the fan fiction story.

If we didn’t have this inferential quarantine between imaginative models, we would not be able to read fan fiction while also properly appreciating the original stories. Conceiving of imagination as a faculty of building many inferentially separated models explains how we can engage with many imaginary worlds without mistaking them for one another or

muddling up our belief box. We can also keep all the effective cognitive architecture of the

boxology view, and thus not sacrifice any of the other desiderata. Furthermore, locating the separateness of imaginary worlds at a subpersonal, cognitive level ensures that we don’t have to resort to metarepresentation to explain why everyone, even very young children, knows that SpongeBob is ‘not real’ in the world of Batman.