Surrealistic Imaging Experiment #1

"The case against the realist position needs to be considered, after considering the materialist position. The latter, more poetic however than the former, admittedly implies on the part of a Man, a monstrous pride, but not a new and more complete degeneration. It should be seen, above all, as a welcome reaction against certain ridiculous spiritualist tendencies. Ultimately, it is not incompatible with a certain nobility of thought.

The realistic position, in contrast, inspired by positivism, from Thomas Aquinas to Anatole France, appears to me to be totally hostile to all intellectual and moral progress. It horrifies me, since it arises from mediocrity, hatred and dull conceit. It is what engenders all the ridiculous books, and insulting plays of our day. It feeds on newspaper articles, and holds back science and art, while applying itself to flattering the lowest tastes of its readers; clarity bordering on stupidity, the life lived by dogs."

-from the Surrealist Manifesto, by André Breton (1924)

Surrealism was a philosophical movement in art and literature that embraced the unexpected, the impossible, the dream-like elements hidden from waking life. The founder of surrealism was French writer and poet André Breton, who was trained in medicine, psychiatry, and Freudian psychoanalysis. He defined surrealism as "Pure psychic automatism by means of which one intends to express, either verbally, or in writing, or in any other manner, the actual functioning of thought. Dictated by thought, in the absence of any control exercised by reason, free of any aesthetic or moral concern." Breton clearly had no use for the realist position, which he viewed as a pox on society. Eighty-eight years later, he might find it ironic that surrealism itself is the subject of positivist thought and scientific investigation.


Does the brain process surrealistic art in a different fashion than realistic art? 

Why yes, one would expect that to be the case. Undaunted, Silveira and colleagues (2012) asked this question in a recent fMRI study. I would predict that surrealist art is more computationally intensive for the Bayesian brain, so there would be greater activation in regions associated with top-down visual processing in an attempt to construct a coherent meaning from an unusual image.¹ There was a precedent for this position in a study that compared the activations produced while viewing possible and impossible objects (Wu et al., 2012). Briefly, regions in both the dorsal and ventral visual streams showed greater activation for impossible than for possible objects.²


The authors of the current study adopted a different perspective (so to speak):

While naturalistic paintings present the world in a habitual way, surrealistic paintings violate the expected frame of reference. Surrealistic paintings are characterised by presenting mainly recognisable objects but in constellations that do not exist in real life or that are impossible from a physical point of view. In presenting impossible scenes, these artworks prevent an effortless processing of information to come to a meaningful interpretation of the visual world. ... We hypothesised that percepts violating an expected percept cannot be integrated effortlessly into a frame of prior experiences or expectations and therefore also lack the potential for self-reference. As it has been assumed that cortical midline structures refer to such self-representations (Han and Northoff 2008), we expected naturalistic and surrealistic paintings to have different activations in these areas.

The major prediction was that surrealistic images cannot engender self-referential processing, so differences in cortical midline structures (medial prefrontal and posterior cingulate cortices) were expected, with no further mention of dorsal/ventral stream visual regions, top-down input from prefrontal cortex, networks for processing novelty, or lateral temporal regions associated with semantic processing.

Figure S2 (Silveira et al., 2012). Reproductions of naturalistic and surrealistic artworks. N = naturalistic, S = surrealistic. N1: Edward Hopper “Sunday”. N2: Edward Hopper “Morning Sun”. N3: Eric Fischl “Japanese Bath”. N4: Francisco de Goya “La Cometa”. N5: Edward Hopper “Chop Suey”. N6: Francisco de Goya “Niños con Mastines”. N7: Edward Hopper “Summer Evening”. N8: Edward Hopper “Cape Cod Morning”. S1: René Magritte “Son of Man”. S2: Vladimir Kush “Pearl”. S3: Salvador Dalí “My Wife Nude”. S4: Max Ernst “Elephant Celebes”. S5: Vladimir Kush “Walnut of Eden”. S6: Giorgio de Chirico “Hector and Andromache”. S7: René Magritte “Le Prêtre Marié”. S8: Vladimir Kush “Departure of the Winged Ship”.


The final stimulus set of 8 realistic and 8 surrealistic paintings is shown above. These were selected from a larger set of images rated on valence, arousal, and familiarity by a separate group of participants. Highly familiar pieces were excluded.³ The control stimuli were homogeneous color fields. All pictures were matched in size, luminance, color saturation, and spatial frequency parameters. Each picture was presented 3 times, and the task was to make a binary decision about their reaction to the image: “Are you touched by the painting?” The subjects were equally affected by the realistic and surrealistic paintings, but took longer to decide on the realistic ones.

The major neuroimaging result was obtained using a subtraction analysis to compare the BOLD response to naturalistic vs. surrealistic paintings. There was significantly greater activation to the naturalistic pictures bilaterally in the precuneus (Brodmann area/BA 7) and medial occipital cortex (BA 17, 18, 19) and in the right middle temporal gyrus. It seemed that no brain areas showed greater activity while viewing the surrealistic images. In fact, the surrealistic pictures resulted in deactivation of the precuneus, medial occipital, and temporal regions when compared to the color field control condition.

Figure 1 (modified from Silveira et al., 2012). Neurometabolic level of processing for naturalistic versus surrealistic images. Sagittal section. Note: Prec = precuneus, MOC = medial occipital cortex.


Given some of the hypothesized roles of the precuneus, the authors' interpretation is plausible:

As a part of the cortical midline structures, precuneus activity has been suspected to be associated with visuo-spatial imagery, episodic memory retrieval, and even of what has been referred to as the “self ” (Cavanna and Trimble 2006). Episodic memory retrieval is very likely to be associated with top–down processing (Sestieri et al 2010). However, surrealist paintings are not only unfamiliar but also disturb our sense of consistency and coherence and may therefore also hardly be related to our sense of the self. The higher activation of the precuneus in the naturalistic condition supports the hypothesis that percepts matching expectations and therefore confirming specific aspects of reality can be linked both to
prior experiences and innate programmes of the representation of the visual world...

What doesn't make sense to me is why there were no visual areas that showed greater activation to the surrealistic images, as in the impossible object study (Wu et al., 2012). Furthermore, it is unclear why the processing of such marked visual/semantic incongruity would not activate any kind of "novelty" circuit in dorsolateral prefrontal cortex, temporal parietal junction, and hippocampus, or semantic regions in the lateral temporal lobe. A very interesting electrophysiological study (using non-invasive ERP recordings, or event-related potentials) found a component at 390 msec post-stimulus that was related to mismatches between scenes and objects, as shown below (Ganis & Kutas, 2003). The authors speculated that this N390 scene congruity response "reflects the action of visual scene schemata stored in the anterior temporal lobe."

 modified from Fig. 1 of Ganis & Kutas

A green apple floating in front of someone's face (S1), or a ship's sails made out of butterflies (S8), might involve a similar violation of visual scene schemata.

"We are still living under the rule of logic, that, of course, is what I am driving at. But in our day, logical procedures are only applicable in solving problems of secondary interest. The absolute rationalism still in fashion only allows us to consider facts directly related to our own experience. The aims of logic, in contrast, escape us. Pointless to add that our very experience finds itself limited. It paces about in a cage from which it is more and more difficult to free it. It leans, it too, on immediate utility, and is guarded by common sense. Under the flag of civilisation, accompanied by the pretext of progress, we have managed to banish from the spirit everything that might rightly or wrongly be termed superstition, fancy, forbidding any kind of research into the truth which does not conform to accepted practice. It was by pure chance, it seems, that a part of our mental world, and to my mind the most important, with which we pretended to be no longer concerned, was recently brought back to light."

-from the Surrealist Manifesto, by André Breton (1924)

Footnotes

¹ So once again, we have a challenge for Bayesian theorists and their "free energy principle" (see Free-energy minimization and the dark-room problem), which seeks to reduce uncertainty.

² See That's Impossible! How the Brain Processes Impossible Objects for details of that study:

The paper started by reviewing the basic neuroanatomy of the visual system and its division into dorsal ("where") and ventral ("what") visual streams. Objects are primarily represented in the ventral stream, and the lateral occipital complex (LOC) is one area that seems to be specialized for object recognition. The authors predicted that impossible objects would be difficult for the LOC to process; therefore, additional regions would be recruited...

What were the results? As predicted, regions in both dorsal and ventral visual streams showed greater activation for impossible than for possible figures: right superior parietal in the former and right fusiform and inferior temporal gyri in the latter.

 

³ The Magrittes weren't familiar? Especially “Son of Man”? Really?


References

Ganis G, Kutas M. (2003). An electrophysiological study of scene effects on object identification. Cog Brain Res. 16:123-44.

Silveira S, Graupmann V, Frey D, Blautzik J, Meindl T, Reiser M, Chen C, Wang Y, Bao Y, PöppeI E, Gutyrchik E (2012). Matching reality in the arts: self-referential neural processing of naturalistic compared to surrealistic images. Perception, 41 (5), 569-76 PMID: 23025160

Wu, X., Li, W., Zhang, M., Qiu, J. (2012). The neural basis of impossible figures: Evidence from an fMRI study of the two-pronged trident. Neuroscience Letters 508:17-21.

Yves Tanguy, Indefinite Divisibility (1942)