The word imagination covers a spectrum of meanings in everyday language, from the experiencing of vivid images in different modalities, to states of mind such as daydreaming, characterized by fantasy and fluidity of thought, to the generation of novel ideas and outputs. Though imagination is typically associated with artistic spheres, scientific investigation also involves intuitive 'leaps in the dark' and other hallmarks of imaginative thought. The chemist Mendeleev is reputed to have woken from a dream in which the elements of the Periodic Table were laid out as patience cards, thus solving in imagination the problem that had eluded him during many weeks of effortful reasoning.
1. Imagination and psychological theory 2. Components of imagination 3. Evolution of imagination 4. Development of imagination in children 5. Impairment of imagination 6. Imagination and mental disorder 7. Imagination and the brain1. Imagination and psychological theory
Contemporary child-rearing and educational practices stress the importance of fostering children's imagination, and in adult life a high premium is placed on activities and outputs which demonstrate imagination. Evolutionary theorists see it as a crucial feature of the cognitive apparatus which sets humans apart from other animals. Yet studies of imagination have played a comparatively small part in mainstream psychology — reflecting theoretical influences which have acted in combination to downgrade its importance. Behaviourists deemed imagination, along with consciousness and other complex attributes of mind, a meaningless construct, because it was impossible to operationalize or measure. Psychodynamic perspectives have recognized its significance, but presented it as 'primary process thinking' — a primitive, associative, non-rational form of thought linked to both dreaming and pathology. In reaction to this, cognitive psychology has either ignored imagination, or sought to explain it within the framework of conscious, logical reasoning processes — 'secondary process thinking' — which is its central subject matter. The theoretical hiatus between psychodynamic and other accounts, which obscures the probable role of both associative and logical processes (Martindale 1999), has stunted the development of a satisfactory psychology of imagination. Where the term features (for instance, in research on pretence), the imaginative content of the activity is rarely clearly defined.
The first task for a psychology of imagination is therefore to identify a configuration of characteristics which epitomize imaginative processes and distinguish them, albeit in degree, from other forms of thought.
2. Components of imagination
Mental imagery — the capacity to 'see things in the mind's eye', or indeed 'hear them in the mind's ear' — is the most obvious concomitant of imagination. If we ask someone to imagine themselves on holiday, they may report sights, smells, sounds, and tastes from an actual holiday, that is, memories of past experiences stored or accessed in the form of images (see
mental imagery for a discussion of the representations involved). However, imagination is not necessarily or exclusively image based. The processes outlined below are likely to involve verbal as well as non-verbal or imaginal thinking.
Counterfactual thinking — the capacity to disengage from reality in order to think about events and experiences which have not actually occurred and might never occur — is a crucial feature of much imaginative thought. Thus the holiday which a person sees in his mind's eye may be one he has never had. Counterfactual imagining is also involved in contemplating potential courses of action, fantasy and pretence, and understanding other people's thoughts, beliefs, and desires (so-called Theory of Mind), all of which are likely to involve verbal as well as non-verbal processes.
A third characteristic of imagination is
symbolic representation, the use of concepts and images to evoke or represent real-world entities, or the use of one set of real-world entities to evoke others (e.g. as when a child uses a stick as a gun in pretend play). It is hard to conceive of any form of thought which does not involve such symbolism. However, imagination appears distinctive in the quality and scope of the symbolism involved. An artist or poet may use paint on paper or words on a page to evoke imaginative ideas which transcend regular references or meanings. Mithen (1998) describes the basis for this as cognitive fluidity — the exchange of concepts between different cognitive domains, such that laws applying in one domain can be broken in another. Thus a sequence of notes may be 'heard' as a mountain stream; a child engaged in a pretend fight readily accepts that an ordinary twig 'is' a sword; an adult may believe in life after death, or that supernatural beings can travel through solid objects.
Cognitive fluidity also underpins the capacity, crucial for imagination, to operate on familiar symbolic representations generating novel ones. This manifests itself most obviously in the works of creative artists. A composer, for instance, may work with the same set of notes or harmonies to generate entirely new compositions. This raises the difficult question of how, if at all, imagination differs from
creativity. According to one contemporary approach imagination is a basic and universal characteristic of human cognition, while true creativity is the attribute of an exceptional, talented minority. Thus Boden (1990) points out that, while all humans possess the imagination necessary to generate new combinations of thoughts or words, true creativity transcends such routine generativity. However, other researchers see creativity as a universal human attribute, and, as such, perhaps indistinguishable from imagination.
An alternative criterion for distinguishing imagination and creativity revolves around the production of outputs. While the act of imagining something can be an entirely personal experience, the concept of creativity is closely associated with the generation of social and cultural products such as music and works of art. Such outputs originate in the imagination of one individual, and have the power to evoke imaginative responses in others. But some recent theories emphasize that both imaginative thought and creative outputs have their sources in social interactions between individuals, once again questioning the idea that creativity is an individual and special talent. It may be soundest to adopt an intermediate position — that imagination reflects universal human processes which are particularly enhanced in those individuals or those interactions that generate creative outputs.
Finally, it seems likely that certain states of mind, accompanied by modifications in brain activity, are particularly conducive to imaginative thought. Martindale (1999) notes that the imagination-rich thinking involved in discovery, creation, and problem solving reflects distinct cognitive phases. The initial phase is typically dominated by the conscious, logical, reality-oriented reasoning referred to earlier as secondary process thinking. Following this is an 'incubation phase' — a 'fallow period' in which no apparent progress on the task is made, and the person may experience a powerful sense of frustration and block. Eventually there is an illumination, or solution, typically when the individual's mind has not been consciously 'focused' on the problem for a time. Both the incubation and illumination phases are thought to be characterized by free-associative, non-logical, or primary process thinking.
The emotional euphoria which often accompanies illumination is epitomized in the apocryphal tale of Archimedes shouting 'Eureka' as he jumped from the bath. A sustained form of euphoria, the hypomanic mood, typically preceding manic breakdown, in which many great composers and artists have been most prolific, is believed to involve atypical functioning of neurotransmitters and brain circuits (Nettle 2001). Further ideas about brain activity are considered later on.
3. Evolution of imagination
Studies within cognitive archaeology and evolutionary psychology suggest that fully fledged imagination may have emerged only in the last 100,000 years, as a unique characteristic of
Homo sapiens sapiens. As much as 2 million years ago, members of the first species of the genus
Homo (Homo habilis) displayed a limited capacity to 'imagine' a future outcome, in their ability to fashion stones into simple tools. Since they transported these tools to distant sources of food, these hominids could also perhaps 'see' in their mind's eye locations they had visited earlier. But these embryonic forms of imagination were practised imitatively and inflexibly for a further 1.5 million years, with only gradual changes in technological and behavioural complexity and, by implication, cognitive sophistication. According to Foley (1995), the capacity for counterfactual thinking was a later and crucial evolutionary stage, which coincided with the significant increase in hominid brain size some 300,000 years ago. A hominid capable of imagining the possible outcomes of different actions, or the possible responses of its peers, would have the selective advantage of control over its physical and social environment, uncompromised by expenditure of energy in physically enacting and evaluating alternative outcomes.
From 50,000 years ago, there was a so-called 'symbolic explosion', a proliferation of creative activity including cave art depicting scenes as much imaginary as real, and decorative artefacts, such as the 30,000-year-old Hohlenstein–Stadel statuette of a fantastic creature, half lion and half man (see Fig. 1). Since all the different elements of imagination — imagery, symbolism, counterfactual thinking, novelty, and creative output — are evident during this period, it seems plausible to locate the full flowering of modern imagination here. According to some researchers (Clottes and Lewis-Williams 1998), the humans of this era even understood the role of altered state of mind in promoting imagination, using trance states and hallucinogens to enhance their own powers.
However, we cannot rule out that earlier peoples engaged in rituals, told stories, or fashioned fanciful objects from materials which have perished. Moreover, since modern humans (
Homo sapiens sapiens) appeared approximately 150,000 years ago, the reasons for a 'watershed' in imaginative behaviour at around 50,000 years are unclear. Mithen (1998) has argued that the symbolic explosion represents the culmination of evolutionary changes occurring
beyond the first appearance of humans, in which a strictly modular cognitive architecture (see
cognitive modularity), adapted to deal entirely independently with domains such as the natural world, technology, and social relations, was superseded. A system of flexibly interacting modules, permitting cross-talk between different domains, might confer greater capacity not only for technological innovation, but also for anticipating future actions, and for cooperation in complex social groups, with, as a by-product, the ability to pretend that a banana is a telephone, or to create (and believe in) a mythical creature. In contrast, Foley and others have suggested that the cognitive capacity for such imagination was fully in place when the first members of
Homo sapiens sapiens started to think in 'what if?' terms. Accordingly, the later 'symbolic explosion' may reflect behavioural and cultural changes, motivated by population pressures and the need to demarcate one social group from another.

Fig. 1. Imagining the impossible: a 30,000 year-old statuette of a 'lion-man'.
4. Development of imagination in children
Current theories of the development of imagination in children echo evolutionary approaches in stressing the link between imaginative thinking and advanced social and cognitive skills. Much of this work focuses on observational and experimental studies of pretence. Typically developing children display simple forms of pretence, such as using one object to represent another, from as early as 12 months. More elaborate forms of pretence unfold thereafter, in which isolated pretend acts become incorporated into complex scripts (such as making a cup of tea), and children adopt pretend roles (such as Batman or 'mothers and fathers') in social interactions. Leslie (1987) described pretence as an ontogenetically early form of meta-representation. The representation 'this is a banana' is decoupled from reality to allow acceptance of the proposition, in pretence, that 'this is a telephone'. This, he argues, 'kick starts' the general capacity for counterfactual thinking. By contrast, Harris (2000) argues that children employ pretence partly in order to learn
about reality. His claim that elements of reality are imported into pretence in order to 'run through' their consequences may explain why a pretend episode such as a fight can generate genuine emotional responses. Both theories give pretence a central role in developing the child's theory of mind, and hence their capacity to enter the social world of other people.
Harris's model encompasses a wide range of childhood phenomena including imaginary companions, belief in magic, and fairy stories. His view of imagination as a sophisticated and logically coherent mode of cognition, which reinforces rather than disrupts the developing child's grasp of social and physical reality, clearly links it with the notion of secondary process thinking. As such, Harris's account provides no obvious sources for the inventive juxtapositions of startlingly disparate ideas which we may see in the work of artists and poets. A complete theory of the imagination needs to address how, if at all, the normal, well-regulated fantasy world of children pretending relates to the exceptional 'zany' imagination which we find, for instance, in surrealist paintings or James Joyce's stream of consciousness. As Martindale (1999) suggests, the capacity for creative imagination may depend upon the facility with which an individual can alternate between primary process and secondary process thought.
5. Impairment of imagination
The extensive imaginative impairments documented in people with
autistic spectrum disorders (ASDs), and the usually profound consequences for how such people engage with the human world, serve as a 'test case' for the importance of imagination in human cognition and social behaviour. Yet if imagination is such a crucial human adaptation, why should genes conferring susceptibility to a condition marked by imagination deficit persist in human populations? Baron-Cohen et al. (2002) have speculated that the presence in early human societies of some individuals with a typically autistic cognitive style, combining diminished imaginative capacity with an enhanced grasp of physical and mechanical systems, might have had certain selective advantages. These would be the individuals who, while the shamans contacted the spirit world, or dealt with social disputes among kin, and while the artists embellished cave walls, would be fulfilling other functions such as predicting the path of an oncoming storm, or building a robust dwelling.
The paucity of pretend play in children with ASDs is such a robust finding that it now forms part of a clinical tool for the early detection of autism (Baron-Cohen et al. 1996). A child with autism given a pile of toy bricks is likely to arrange them obsessively in patterns or colours, but unlikely to use them for a 'tea party' or a make-believe train. Difficulties in imagining other people's thoughts (
Theory of Mind) have been extensively documented using tasks such as false belief (Baron-Cohen, Leslie, and Frith 1985) which require an understanding that another person's belief about a situation might be different from one's own.
Of particular interest in this context are studies by Craig and colleagues. One study, based on the Torrence tests for creativity, highlighted the inability of children with ASDs to generate a range of novel interpretations for a junk object. Another (Craig, Baron-Cohen, and Scott 2001) showed that these children lack precisely the imaginative capacity which enabled our ancestors to fashion a lion man. The children were unable to produce drawings of fantastical creatures combining, say, the top half of a fish with the body and legs of a mouse. Yet their drawings of real-world creatures were unimpaired, reinforcing the notion that full-blown imagination requires not just the ability to 'see in the mind's eye', but also to manipulate and combine mental images fluently and in defiance of domain-specific constraints.
Yet any interpretation of imaginative impairments in ASDs must accommodate substantial variations in their severity across the spectrum. For instance, some people with Asperger syndrome or high functioning
autism have a measure of social imagination in the form of partial Theory of Mind skills. The recent case of an autistic child with exceptional poetic and literary skills (Mukhopadhyay 2000) and the claim that geniuses such as Beckett and Wittgenstein suffered from Asperger syndrome (Glastonbury 1997) argue for a complex relationship between imaginative impairment and ASDs.
6. Imagination and mental disorder
We find a mirror image for imaginative impairment in the wild, uncontrolled imagination that accompanies mental disorders such as manic depression and psychosis. Some research (see Jamison 1993) suggests that composers and artists such as Schumann and Van Gogh have been particularly prolific during hypomania or borderline psychosis, states that precede actual breakdown, when thought and behaviour become too disorganized for creative output. The gradual onset of schizophrenic illness in the painter Louis Wain is precisely charted in his series of cat paintings, first animated and intriguing, then developing an increasingly nightmarish, demonic, and fragmented quality as the disorder took hold.
Studies of the family trees of exceptional people suggest the presence of traits which, depending on genetic loading and environmental circumstances, may be expressed as an outstanding imaginative talent, or mental disorder, or a combination of the two. Nettle (2001) concludes that the same brain processes which promote originality and mental fluidity as key components of imagination can also, depending on environmental circumstances, lead to mental disorder. Like Baron-Cohen, Nettle sets this, speculatively, in evolutionary context: genes which promote the adaptive attributes comprising exceptional imagination carry with them the cost of susceptibility to mental disorder.
Atypical functioning of brain processes and circuits is implicated both in the 'strong imagination' described by Nettle, and contrastingly, in autism, with its impairments in social and creative imagination. This returns us to the intriguing question of how imaginative processes generally are instantiated in the structure and activity of the brain.
7. Imagination and the brain
The notion that we could identify brain specific correlates for imaginary thoughts, such as that of a lion man, seems far fetched. However, both PET and fMRI studies have begun to reveal some of the areas of the brain involved in imagery, which as we saw earlier is a basic, though not universal, feature of imagination. As Damasio observes, cortical brain circuits involved in creative imagination are shaped by each individual's activities and experiences.
Of particular interest are PET studies indicating that imagining oneself involved in a particular action may activate the same areas of the brain as actually performing the action (see Robertson 2002). Moreover when such imaginary movements are mentally practised repeatedly, the relevant motor areas of the brain exhibit sustained changes similar to those which occur when the movements are practised physically. This fascinating finding explains the efficacy of the 'mind game', the technique of imaginary practice used by many top sports people and musicians.
Similar results occur in visual imagery tasks. When a participant is asked to imagine a particular object, the primary visual cortex is activated, as it would be on actually viewing such an object. However, when a person mentally accesses familiar images — whether of movements or objects — he or she must also be using those brain regions where the relevant memories are laid down. This is effectively highlighted in a study by Maguire, Frackowiack, and Frith (1997). London taxi drivers, famed for completing 'the knowledge' — the intensive training in negotiating the highways and byways of London — were PET scanned while imagining the routes they would take to familiar locations. The scans indicated intense activity in the right
hippocampus, where, it seems, the spatial memories of the routes had been laid down.
Studies of the brain activity involved in imagining familiar objects or routine movements unfortunately tell us little about what brain activity underpins more complex forms of imagination. What happens, for instance, when we think about an event which has never occurred, pretend to be a train, or create an entirely novel object in the mind's eye? The relevant experiments have never been done. However, as many researchers have noted, such activities require mental fluidity — the combination and transformation of images or thoughts from the same or different domains. Damasio may therefore be correct in proposing a key role for the frontal lobes, which are involved in organizing and coordinating information from different parts of the brain. Yet frontal lobe activity also operates to inhibit 'irrelevant' thoughts and actions. Since this could potentially suppress precisely those eccentric connections that mark creative imagination, perhaps imaginative thought involves, at different phases, both upward and downward modulation of frontal lobe activity.
Electroencephalography (EEG) studies (see Martindale 1999) support the idea that fluctuating levels of cortical (and particularly frontal) arousal are related to imaginative thought.
Studies of the relation of brain activity to imaginative thought are clearly in their infancy, but one final study merits inclusion here. Gruzelier et al. (2002) have made EEG recordings of brain activity during a controlled trial of biofeedback training designed to enhance the imaginative performance of musicians. The performance of young musicians at the Royal College of Music was evaluated before and after they had learned to control their own brain rhythms. The learned capacity to evoke theta-wave activity over other frequencies was found to be correlated with the musicians' imaginative involvement in their performance, as evaluated by independent experts. The idea that brain activity might eventually be harnessed to enhance imaginative thought provides a suitably optimistic conclusion to this discussion.
(Published 2004)— Ilona Roth
Bibliography- Baron-Cohen, S., Leslie, A. M., and Frith, U. (1985). 'Does the autistic child have a theory of mind?' Cognition, 21.
- — — Cox, A., Baird, G., et al. (1996). 'Psychological markers in the detection of autism in infancy in a large population'. British Journal of Psychiatry, 168.
- — — Wheelwright, S., Lawson, J., Griffin, R., and Hill, J. (2002). 'The exact mind: empathising and systemising in autism spectrum conditions'. In Goswami, U. (ed.), Handbook of Cognitive Development.
- Boden, M. (1990). The Creative Mind.
- Clottes, J., and Lewis-Williams, D. (1998). The Shamans of Prehistory: Trance and Magic in the Painted Caves.
- Craig, J., Baron-Cohen, S., and Scott, F. (2001). 'Drawing ability in autism: a window into imagination'. Israel Journal of Psychiatry and Related Sciences, 38.
- Damasio, A. R. (2001). 'Some notes on imagination and creativity'. In Pfenninger, K. H., and Shubik, V., The Origins of Creativity.
- Foley, R. (1995). Humans before Humanity.
- Glastonbury, M. (1997). 'I'll teach you differences: on the cultural presence of autistic lives', Changing English, 4.
- Gruzelier, J. H., Egner, T., Valentine, E., and Williamson, A. (2002). 'Comparing learned EEG self-regulation and the Alexander technique as a means of enhancing musical performance'. In Stevens, C. et al. (eds.), Proceedings of the 7th International Conference on Music Perception and Cognition, Sydney 2002.
- Harris, P. L. (2000). The Work of the Imagination.
- Jamison, K. R. (1993). Touched with Fire: Manic-Depressive Illness and the Artistic Temperament.
- Leslie, A. M. (1987). 'Pretense and representation: the origins of "theory of mind" '. Psychological Review, 94.
- Maguire, E. A., Frackowiack, R. S. J., and Frith., C. D. (1997). 'Recalling routes around London: activation of the right hippocampus in taxi drivers'. Journal of Neuroscience, 17.
- Martindale, C. (1999). 'Biological bases of creativity'. In Sternberg, R. J. (ed.), Handbook of Creativity.
- Mithen, S. (1998). 'A creative explosion? Theory of Mind, language, and the disembodied mind of the Upper Palaeolithic'. In Mithen, S. (ed.), Creativity in Human Evolution and Prehistory.
- Mukhopadhyay, T. (2000). Beyond the Silence: My Life, the World and Autism.
- Nettle, D. (2001). Strong Imagination.
- Robertson, I. (2002). The Mind's Eye.