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SCIEN TIFIC COMMENTARY
Capturing creativity
Creativity is a mental journey between ideas or concepts
that involves either a novel route or a novel destination.
Many underlying causes have been suggested, including
divine intervention and serendipity, but an adequate
account must consider its neurobiological bases (Zeki,
2001). Brain theories of creativity might be divided in the
broadest terms into global theories (based on universal
aspects of brain function or universal influences on it) and
local theories that emphasize certain components. Links
between creativity and intelligence (Hofstadter, 1995;Sternberg, 2001), transmitter function (Beversdorf et al.,
1999; Schrag and Trimble, 2001) or mood (Ludwig, 1994)
all arguably reflect global mechanisms. In terms of local
theories, there is ongoing debate about the relative
importance of frontal and posterior association cortices
(Heilman et al., 2003) and the relative importance of the
right and left hemisphere (Amaducci et al., 2002). Other
structures that have been emphasized include the cerebel-
lum, albeit as part of a broader network (Chavez-Eakle
et al., 2007).Particular problems with the study of natural creativity
are the fact that a given creative event is unique to any
individual and the restriction of creativity to particularcircumstances; the creative process that led Einstein to
develop a special theory of relativity only happened once
(further rehearsal of the concepts does not constitute
creativity) and we would not dispute his creative genius
based on a consideration of his violin playing. The creative
process is therefore not well suited to the use of traditional
psychological methods based on the observation of group
performance over multiple trials in stereotyped circum-
stances. Specific forms of creativity can be studied using
imaging in constrained environments (Geake and Hansen,
2005; Chavez-Eakle et al., 2007; Mashal et al., 2007), but
such studies beg the question whether natural creativity canbe captured by tests that depend on particular interpreta-
tions of its generic basis. In this issue of Brain, Seeley and
colleagues take a more ethological approach by observing
the effect of focal degenerative brain disease on the natural
expression of creativity. They describe a fascinating example
of brain degeneration not only sparing creativity but being
preceded by increased creative behaviour.The creative output of a scientist and artist with primary
progressive aphasia (PPA) is described and related to the
distribution of brain atrophy measured prospectively by
voxel-based morphometry. This was made possible by the
existence of MRI scans before the onset of aphasia that were
carried out to follow an acoustic neuroma. The patient
started painting at the age of forty-six and the paintings
evolved into complex cross-modal representations by the
age of fifty-two, eight years before any speech symptoms.
Her painting is assessed from before the onset of aphasia to
a stage when she was still painting despite being mute.
What is particularly interesting in this case is the focus thatthe patient developed on the work of another progressive
aphasia sufferer, Maurice Ravel (Amaducci et al., 2002),
before the onset of her illness: a painting based on Bolero
executed before the aphasia converts the repetitive musical
form into a repetitive visual form. Another painting
produced before the aphasia demonstrates a different
conversion, from mathematics, in which the number pi is
represented in visual form. During the illness itself the
painting style became increasingly close to life. An evolving
pattern of left frontal and temporal cortical degeneration
associated with her aphasia is demonstrated in the
accompanying voxel-based morphometry, with associated
increases in grey matter in the right parietal cortex. Thebehavioural data are interpreted by the authors in terms of
an increase in transmodal creativity realized by intact right
posterior mechanisms that are released from inhibition by
the frontal cortex.The work raises a number of interesting questions, the
most central of which is whether the study really
demonstrates increased creativity corresponding to the
disease process? The early paintings demonstrate a form
of conversion of acoustic or mathematical structure to
visual form beyond simple translation and evidence true
creativity. However, peak creativity defined in terms of the
cross-modal work occurred eight years before the speechsymptoms and structural brain changes. When the disease
was established she exhibited what is arguably a less creative
style. That might still represent a gain of function compared
to when she did not paint, although measuring the
creativity of her previous scientific work is even more
difficult than judging the creativity of her artistic work.
However, the other cases of increased creativity in early
PPA reported by this group argue against coincidence,
and it is possible that the sensitivity of voxel-based
doi:10.1093/brain/awm310 Brain (2008), 131, 6^7
The Author (2008).Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: [email protected]
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morphometry is not sufficient to show early structuralcorrelates of disease at a time when the suggested gain offunction was most marked.
How can we define creativity in a robust way? Themethodology of arts criticism leads to crude metrics such asthe ranking of creative endeavours, likened by one observer
to World Federation Wrestling for middle-class people(Costello, 2003). That is not a basis for useful metrics thatmight correlate with brain morphology. In the laboratory,quantification of creativity in the form of fluid analogies ispossible when the input to subjects and output from themis constrained (Geake and Hansen, 2005), but how can wequantify spontaneous creativity? Quantification of creativitybased on information theory is conceivable, based oncharacterizing the novelty and complexity of either conceptsor the relationship between them. Bolero would notactually come out highly in an assessment of creativitybased on information theory, due to the repetitivestructure, whilst the silent piano piece 433 by John
Cage corresponds to a baud rate that can only ever bebeaten. In visual art the use of information theory to definecreativity would probably suggest that photorealism wasmore creative than cubism, whilst in literature the use ofrelated measures like automated textual analysis (Garrardet al., 2005) might place Hemingway at the bottom of thecreative heap. But the ultimate futility of possible informa-tion theoretic approaches is highlighted by a considerationof the richest possible creative outputs based on metricsderived from it: acoustic noise, visual noise or randomwords. Information theory can never capture the holy grailof creativity: beautiful concepts, ideas or images, which canbe very simple. A reverse view of creativity is an ability tointroduce order into the randomness of nature (E. Hoffer,unpublished). But, at the limit, that takes us back to 433as the ultimate expression of creativity. We are left, then,with an imbalance between the anatomical precision ofvoxel-based morphometry and the absence of any robustmeasure of creativity to which this might be related.
If the association between this pattern of brain structuralchange and creativity is accepted, it raises further questionsabout the adequacy of local theories of creativity. These all
emphasize areas of association cortex that mediate connec-tions between cortical areas (or the cerebellum as asubcortical structure with extensive cortical connections).From first principles, posterior association cortex might beadequate for the abstraction between symbolic formscommunicated by the senses, whilst abstraction between
ideas could involve frontal association cortex. The currentstudy suggests that isolated posterior mechanisms are not
an adequate basis for creativity expressed through abstrac-tions between sense data.
Timothy D. GriffithsCognitive Neurology Clinic, Newcastle General Hospital
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Scientific Commentary Brain (2008), 131, 6 ^7 7