The study of neurological patients with focal brain damage has served as a reliable and valid source for understanding functional brain localization. We have seen throughout this book that art production continues to be executed in established artists despite the damage, its etiology, or extent. This suggests a wide and diffuse representation of art talent and skill. The skill that produces art works appears to recruit several neuronal networks. Acquired damage to the right hemisphere or to the left hemisphere, in various focal areas, does not lead to disappearance, abolishment, or elimination of artistic production. Nor does the ability to draw objects from memory by non-artists disappear following similar damage. Talent, extensive lifelong practice, and skill preservation all suggest redundancy in functional representation and explain the spared artistic capacity.
In addition, what does not happen as a result of insult to the brain is a switch in art genre, as in realism, Surrealism, abstract, and so on. So we do not see a shift from realistic to abstract depictions, and vice versa (see introduction to Chapter 2, where artistic style is defined). The oeuvre does not change. Importantly, whatever is different in the post-damage art is not unaesthetic or unartistic or uncreative. Indeed, artistic skill preservation is remarkable given the extent of brain damage in some artists.
The issue of skill preservation in the case of Edouard Manet is revealing: Manet was diagnosed around 1878 with severe locomotor problems in the left leg (inability to walk or move with that leg), a symptom of cerebral neurosyphilis (Boime, 1996). Eventually, a gradual paralysis developed in the leg, greatly hampering his walking. He also experienced excessive fatigue and pain. All these symptoms interfered with his work to some extent and may explain, in part, increased numbers of creations in pastels. It is difficult to say when exactly he contracted the syphilis. The effect of his illness may be particularly evident in one of his large last paintings, completed in 1882, A Bar at the Folies-Bergère (Boime, 1996). In this painting, Manet depicts a central figure of a barmaid in the foreground. In the background is a huge mirror in which numerous objects and human figures are shown. The depictions in the mirror do not faithfully obey physical laws of light reflection. This in turn raises the tantalizing possibility that Manet’s brain illness affected some of his spatial cognition (greater neural degeneration in the right hemisphere?), interfering somewhat with correct assessment of angles of sight in mirror reflections, without affecting his artistic skills to convey meaning and aesthetics. The painting is a subject of much debate and speculation by art historians with regards to what Manet intended to convey (Collins, 1996; Galligan, 1998).
Art is ubiquitous throughout the world, with the earliest of signs appearing probably more than 300,000 years ago, with the greatest influx of artifacts emerging (surviving) in Western Europe around 35,000 to 45,000 years ago. It is highly likely that the beginnings of art were expressed by early hominins in both the visual and musical domains, and that art included dance in combination with music. It is not unreasonable to speculate that art expression and language development proceeded in parallel. We have seen in the artists with brain damage that art and language are dissociable but not antagonistic functions. In both there is reliance on pre-existing biological mechanisms and neuroanatomical structures supporting cognitive and symbolic abstraction. Further unraveling of the neural substrates of art should shed light particularly when viewed through the lens of art’s communication value, particularly when it is considered that only humans create art spontaneously. Future experimental procedures could potentially unravel additional perspectives on how art and the brain are related.
Viewing art expression as a mode of communicating, even when general cognition, social behavior, motor abilities, and language fail, explains why there can be practical benefits from art therapy. Normal language interaction is highly sensitive to brain damage, as are vast areas of non-language knowledge. Art, on the other hand, engages several sensory and cognitive systems, including vision, attention, spatial knowledge, concepts, planning, and many more, all of which have widely distributed representations in the brain. There does not seem to be a single “art production” specialist structure in the brain. Given the communicative basis of art, and that language impairment hampers the normal route of communicating, it is not surprising that non-artist neurological patients experience mental well-being and look forward to expressing whatever they can through art (Bungay & Clift, 2010; Leckey, 2011). Indeed, this engagement is practiced in many centers throughout the world and is prescribed for people with depression, mental illness, and brain lesions (Bungay & Clift, 2010). Such prescription has been lauded for being effective in several studies (for a review see Leckey, 2011). This is particularly true in the plastic visual arts (e.g., paintings, drawings, engraving, sculpting). Several studies examining the effectiveness of music therapy in different types of dementia report that, although there is no improvement in general cognition, in contrast, music listening, playing an instrument, singing, and similar musical activities improve some aspects of concentration and social behavior, and facilitate general feelings of well-being (Li, Wang, Chou, & Chen, 2015; Raglio et al., 2012; Stegemöller, 2014). The conclusions of a meta-analysis review of art therapy in dementia and other forms of brain damage is that the therapy does not “bring back” the cognition that has been lost but rather taps preserved functions supported by relatively intact regions (Moss, Donnellan, & O'Neill, 2012). Indeed, as the next paragraph describes, new learning can take place.
Examples of benefits from art therapy are provided in this and the next paragraph. Two Japanese patients diagnosed with frontotemporal dementia but with the frontolobar type (FTLD) suffered from serious verbal communication difficulties (Midorikawa, Fukutake, & Kawamura, 2008). Neither initiated drawing spontaneously, unlike the de novo cases described in Chapter 4; caretakers and physicians suggested taking up this activity. The first case was a woman aged 53 years at the time of diagnosis. Earlier, at age 49, she had noticed verbal difficulties, which progressed and interfered with her daily life. A magnetic resonance imaging (MRI) scan revealed atrophy in the left temporal lobe. The second case was a 63-year-old farmer with verbal and memory deficits, and here, too, an MRI showed atrophy in the left temporal lobe; in addition, there was evidence for white matter infarctions.
In the present study, the 2 Japanese patients with FTLD also had the following characteristics. First the main common deficit in both was semantic dementia. Second, both patients developed drawing behavior after the onset of FTLD, despite not having been artists or having any interest in drawing before the illness. Third, the pictures drawn by both were realistic as opposed to abstract in character.
(Midorikawa et al., 2008, p. 226)
What distinguished their productions was the absence versus presence of the drawn object: case one drew figures from memory, whereas case two drew from models present at the time of drawing. Their drawings did not display exceptional artistic talent or creativity, although they enjoyed producing them.
A truck driver by profession suffered a closed head injury at age 44 years when he accidentally fell from the back section of his loading truck (Midorikawa & Kawamura, 2014). Three years after the accident, when he was 47 years old, an MRI scan showed damage in the left temporal and frontal lobes. Neuropsychological evaluation disclosed verbal deficits and memory deterioration, but with relatively unimpaired visuo-spatial functions. His interest in art began only five years following the injury, and this was while attending a daytime treatment center. Even though his artistic production was not spontaneous, it indicates the ability to learn through clinical art intervention. This newly acquired skill (he did not engage in visual art prior to the injury) did not generalize to improvements in language or other cognitive abilities, showing that the visual art expressive system can tap a functionally separate pathway.
In music we have the remarkable case of JK, a patient diagnosed with frontotemporal dementia. The case illustrates the ability to learn an art form even when other cognitions, including language and social behavior, are compromised (Cho et al., 2015). JK was first seen clinically at age 59, when an MRI scan revealed mild bilateral frontal lobe atrophy, more on the left than the right, as well as some bilateral left temporal pole atrophy, more on the left than the right. Following clinical diagnosis and at the suggestion of his wife, he began to take lessons in playing the saxophone. Previously he had not played any musical instrument nor did he know how to read musical notes. The first few lessons were difficult but he improved with time and even learned to play several musical tunes (Korean folk songs). Brain degeneration progressed nevertheless and another MRI scan a few years later revealed severe atrophy in the same regions plus in the left insula. Behavioral, cognitive, and language impairments worsened as a result of the atrophy but his saxophone playing did not cease. His musical playing skills were highly regarded by his teacher (who taught him in a class together with healthy students), but four years after initial diagnosis he was not capable of learning additional tunes, presumably because of further brain deterioration.
All of these examples illustrate a principal theme in this book, namely that artistic realizations are supported by diffuse and distributed pathways that somehow escape the ravages of brain damage, and thus allow expression despite compromise of other communicative functions.
What is it about the human brain that permits the realization of artistic expressions despite extensive damage? Identifying neuroanatomical differences between humans and non-human primates is valuable for understanding human-unique capabilities, in general, and the mechanisms involved in the spontaneous production of art, in particular. While humans share an enormous amount with other animals genetically—brain structure layout, synaptic organization, and even some cognitive abilities—humans remain unique in the way their brain evolved and the remarkable abilities afforded by it (Suddendorf, 2013). The most notable difference is the large size of the human brain relative to other primates; it is approximately three times as large as a chimpanzee’s. Recent genetic evidence revealed that, in humans, there is a greater production of progenitor cells destined to become neurons than in any of the higher apes (Florio et al., 2015). However, size alone does not explain the art question nor any other cognitive human expressions, since size and brain growth are not uniform throughout.
Several types of differences in the brain have been discovered: regional expansions of some lobes, dendritic organization and arborization patterns, axonal pathways and their connectivity and genetic markers. The pattern of size expansions within the brain might provide clues: some areas, notably the sensory cortex, have remained largely unchanged while the association areas have expanded substantially. In other words, comparing the expansion of the brain from monkeys to chimpanzees to humans has revealed non-uniform changes throughout. Large expansions have been found in the entire length of the temporo-parietal junction, in the ventrolateral prefrontal cortex, in the dorsal anterior cingulate cortex, and in parts of the inferior parietal lobule (Chaplin, Yu, Soares, Gattass, & Rosa, 2013).
Of great interest is the evolutionary expansion size-wise of a particular area situated at the tip of the prefrontal lobe (the pole), also known as Brodmann Area 10 (Semendeferi et al., 2001; Teffer & Semendeferi, 2012; Wallis, 2010). Post-mortem morphology has revealed that the neuronal arborization pattern here is wholly unique to humans: the dendritic spines are particularly dense and form complex patterns. A larger neuropil is found in layers II and III. The latter is explained by increased space for connecting white matter (axons) with the anterior portion of the insula, the anterior cingulate gyrus, as well as with other areas of the prefrontal lobe itself (Semendeferi et al., 2011). Together, this polar area has importance of sorts to human-unique cognition.
There is another notable difference, namely structural hemispheric asymmetries. Two are unique to humans, specifically the language-related network in the left hemisphere and in the same hemisphere the fronto-parietal network (Mantini, Corbetta, Romani, Orban, & Vanduffel, 2013). The spatial parcellations study of the brain by Van Essen and colleagues (Van Essen, Glasser, Dierker, Harwell, & Coalson, 2014) found that the left Sylvian fissure is larger than its homologue in the right hemisphere, and this includes the parietal operculum. Also larger left than right is the part of the lingual gyrus situated in the medial temporal lobe. The left lingual gyrus is associated with semantic color knowledge. In the right hemisphere, the angular gyrus in the inferior parietal lobe is larger than in the left. The right angular gyrus is associated with spatial cognition, spatial attention, and spatial orientation in three-dimensional space.
All of the above in human-unique neuroanatomy can partially help explain why only humans produce art spontaneously. Convergent evidence coming from various experimental techniques and varied neurological etiologies has informed neuropsychology theories since the 1850s. Ideally, a theory or a model that captures the essence of the brain’s control in art would emerge from the exploration of the cases described in this book as well. The potential for a unified characterization is clearly present.
Although elucidation of the art–brain relationship is in its very early stages, some important insights and patterns have been discerned from the explorations in this book. A distinct recurrent type of artistic composition post-damage has not emerged across or within the different etiologies discussed here. For example, one visual artist with aphasia (ZB, described in Chapter 2) produced works that displayed left–right symmetry, reduced depth perspective, and muted colors. Such portrayals are not characteristic of the other artists with aphasia. Why? The myriad approaches available to artists are so varied and diverse that individual artists can depict their art in nearly infinite ways; ultimately, they employ strategies reflecting their neuronal uniqueness. Moreover, the role of functional reorganization in producing variability in post-damage art behavior and production cannot be overlooked (see discussion of functional reorganization in Chapter 4).
At the same time, one clear recurrent outcome that did emerge post-damage, regardless of laterality or lesion localization, is the adherence to the pre-damage artistic style (mode of representation, the genre). Techniques used to express the artistic style, if they were changed at all, were mildly, somewhat, or dramatically so; this could reflect the combined effects of the motoric, sensory, and cognitive consequences of the damage (plus neuronal factors such as reorganization). The combined effects, however, do not fit neatly into a specific neuropsychological theory. For example, the reasons why the aphasia in artist ZB (and the brain damage) co-occurred with a particular artistic profile are not obvious at all. Nothing known about aphasia and its disorders would predict this profile. Nothing known about the functions lateralized to the left hemisphere would necessarily predict it.
Furthermore, in non-artists with left hemisphere damage, we would expect absence of details in pictorial drawings but we would expect to see in the drawings an overall configuration, the gestalt (see Chapters 7 and 8). In artists, however, such dissociation is not observed. Similarly, in non-artists with right hemisphere damage we would expect to see disorders in depictions of convergent perspective and spatial organization, and yet such consistent dissociation is not seen in artists with right hemisphere damage. Even when we consider left hemi-neglect in some of the artists with right hemisphere damage, it is obvious that the artists continued to produce their artistry nevertheless. That is, whatever the neural underpinning of the phenomenon of neglect may turn out to be, that would not be an integral aspect of the neuroanatomy of art. Explanations for the absence of such profiles lie with extensive pre-damage practice of skills and the support of talent by an artist’s particular neural organization (see Chapters 4 and 11).
How do we reconcile the post-damage neuropsychological findings from non-artists? The answer requires careful examination of what is available by way of a theory and model: a significant brain and behavior factor in neuropsychological formulations is hemispheric specialization. Characteristic cognitive and thinking styles of the left hemisphere, besides its main language specialization, include detailed, attentive, piecemeal, analytic, and logical processes (see Chapter 1); right hemisphere computations are assumed to consist of global, wholistic, or gestalt strategies, and this includes facial processing (see Chapters 7 and 8). Somehow, asymmetry in artistic expression post-damage should have materialized according to laterality of damage. But this did not occur, save in one case (the fashion designer described in Chapter 2). The fact that the majority of the data did not fall neatly along hemispheric lines is not discouraging for neuropsychological elucidation of art. The future model or theory would have to be generated from empirical and observational data; it would accommodate what happens to art production (neuropsychologically) when established artists suffer unilateral, focal brain damage, and clearly would need to account for variability in functional reshaping and compensatory neural takeover. Importantly, assessment of cognitive abstraction would need to be performed.
Another recurrent pattern in artists without dementia or autism is the preservation of creativity post-damage. Independently of damage laterality, neuropsychological profile, or etiology, the majority continue to develop and innovate within the boundaries of their chosen genre. Neuropsychology would not have predicted a priori what type of brain damage or its laterality could bring a halt to creativity. Neither right hemisphere nor left hemisphere damage seems to interfere with artistic creativity. The artists here demonstrated that creativity has diffuse functional representation in the brain. In the future, creativity as a notion might need to be parsed further with an eye toward neuropsychological properties (Chapters 1 and 11).
No dramatic alteration in aesthetic preference emerged in the professional artists post-damage. This suggests that when dramatic alterations do emerge, as was documented in some non-artist neurological patients (described in Chapter 9), it is accompanied by strong obsessive–compulsive elements, which are likely the result of extensive brain damage. This type of tissue damage would be expected to disrupt several neuronal systems and to unbalance pathways supporting established preferences. Sorting them out and teasing them apart is a task for future empirical research. Intensity of seeking out preferred art needs to be understood in terms of a continuum. This tantalizing question could be resolved with empirical explorations of rare cases showing dramatic alterations in aesthetic preference, but without the obsessive–compulsive component.
Functional neuroimaging techniques are limited in what they can reveal about the productive aspect of art. Artists conceive their work over the course of an hour, or several hours, or a week, or a month, a period much longer than the time frame practically allowed in a neuroimaging session. In addition, the moment or moments of the creation process cannot be captured with neuroimaging, physiological recording, or transcranial magnetic stimulation. Even MRI scans of the brains of artists are limited, unless a large number are included. In addition, the artificiality of the laboratory, as opposed to the natural setting of the studio, works against an insight into the artist’s brain. Thus, currently, neuropsychological and neurological descriptions of artists with brain damage are invaluable in shedding light on the brain–art relationship.
Observational science can contribute a great deal to the formation of a field of inquiry, as is the case with the artists described in this book. But empirical science can be more effective. There is currently a strong momentum in the elucidation of the brain–art relationship. Experimentation allows verification and testing of assumptions in a manner that can significantly contribute to theoretical formulation and predictions. Quantitative data analysis derived from experiments leads to the creation of further probes that can challenge theories and consequently lead to refinement by way of generalization and extrapolation. When such quantification is applied to a large series of neurological artists, we may see serious progress in a theoretical formulation of the neuropsychology of art.
I hope that the second edition of this book, like the first, will continue to help in the swell of additional reports of neurological cases of established artists. More carefully documented cases are surely needed, and systematic studies could be launched. When this happens, documenting the artist’s attempts at producing artwork after the brain damage will help clarify the issues of functional reorganization and preservation of skills (something noted repeatedly in the cases described here). The immediate post-damage period, on the other hand, could reveal, for example, whether or not artists with right hemisphere damage display spatial deficits (other than hemi-neglect); we would expect such deficits from non-artists. In the immediate post-damage period, what type of skills decline the most, what type of creativity is expressed, and what is the nature of the subject matter are some of the questions that need to be addressed. The sequential, progressive nature could prove most illuminating. There could emerge a strict order in the appearance of distinct artistic techniques and abilities and the order could be extremely useful to know, particularly if the order varies as a function of etiology, laterality, or localization of damage. It would be equally interesting to determine whether the order is invariant with respect to these factors.
Published reports on dementia patients who display artistic skills for the first time only after the disease process set in (de novo) could benefit a great deal from determination of art activity after a certain age in the general population. Let us consider that people with artistic talent put art activity on hold, art having a reputation for being financially unreliable; many are initially discouraged by family members from pursuing artistic careers. They opt instead to invest in professions with secure incomes. Their latent artistic talent lies dormant until retirement time. If we knew the percentage of normal retired people who paint and engage in various valid artistic activities upon ending their lifetime jobs, we might be better able to assess the significance of art production appearing seemingly for the first time in some dementia patients. If both groups have similar percentage rates, this would imply that art in old age, regardless of the presence of dementia, is not that unusual and is not triggered by massive atrophy and pronounced white matter disconnection (as described in Chapter 4).
Even more intriguing, and not dependent on rarity of occurrence as with brain damage in established artists, is a type of quantitative analysis that could shed light on the relationship between language and art. Since we do not know the structure of the first language of the early humans, even of those who created abundant art between 45,000 and 35,000 years ago in Western Europe, perhaps we should consider the issue of language complexity as an influencing factor on the art that is produced. This is testable at the present time. That is, the emergence of art is associated with syntactical language development. Some linguistic variables may be small but their pairing system could yield large, meaningful possibilities. The idea is that the supposed relationship between art and language could vary along a complexity continuum. The complexity of art (the properties will have to be defined) expressed in a certain culture might co-vary in some correlational way with the complexity of the language, the latter being a particular or several linguistic dimensions (the morphology, say). For example, the Piraha people of Brazil’s Amazon region have a remarkably small number of phonemes and a most complex morphology, but practically no art (see Chapter 10). The art–language evolutionary relationship is far from being clear and bears further exploration. It is certainly worth asking the question, for it could provide a handle on the evolutionary emergence of both.