GREENBERG (2004) TRUTH in the BRAIN – The Neuroethology of Belief

ART and the Neuroethology of Belief: Truth in the Brain *
Neil Greenberg

Consciousness Reframed 2004: Sixth International Research Conference

Beijing, 24th – 27th November 2004 by The Planetary Collegium



The perceived “Truth” of a work of art is critical to its effectiveness. Aesthetic experiences associated with both the appreciation and the creation of art engage specific cerebral structures as well as elements of the stress response in order to evoke a more-or-less vivid sense of confidence in its veracity. Recent work in the neuroethology of consciousness and its dysfunctions have identified two general processes that subject incoming information to two complementary “tests” (“reality-testing” and “contextualizing”) which strongly resemble two prominent philosophical views of Truth (correspondence and coherence).


Keywords: consciousness, art, truth, neurology, neuroethology of aesthetic experience


Neurophysiological studies of consciousness and its dysfunctions indicate that two general processes work together in a complementary way to confer more-or-less confidence in the veracity of a belief. These processes can be termed “reality-testing” and contextualizing.” [quotes]

“Reality-testing” involves the validity of information and engages “the processes by which people discriminate the origin of information.” That is, if percepts correspond to “real-world” (veridical) phenomena and are valid representations of the external world. It seems dependent on an “anomaly detector” in the right cerebral hemisphere (Ramachandran 1995).

“Contextualizing” could also be termed “theorizing” or “story-telling” or “narrating.” It involves determining where new information can be situated with respect to all previous information. Contextual plausibility is important here and implies a deep concern for causality. This seems to involve the left cerebral hemisphere’s “interpreter,” posited by Gazzaniga (1992) and Metcalfe (et al. 1995), a frontal/prefrontal structure that generates “causal hypotheses using the information that it encounters in the context of preexisting information.” (Wolford, Miller, and Gazzaniga, 2000)

It is of special interest that these cerebral functions strongly resemble two prominent philosophical views of truth, “correspondence” and “coherence.”

The Correspondence Theory of truth is venerable and seemingly obvious (“Conformity with fact; agreement with reality” –OED) [more]. But its very obviousness is a flaw say adherents of the Coherence Theory [more]. Correspondences between percepts and the real world are not strictly speaking propositions, but objective realities about the world, while to be coherent, a proposition depends upon other propositions. This provides an attractive relativism in which beliefs are true to the degree that they cohere with other beliefs. [quotes]. (But might a coherent assemblage of phenomena, each of which unlikely to be judged “true” in one context, work together in mutual support?. This is an alternative, possibly competitive world view, an “alternate reality.” Such is folie à duex collective hysteria, or the madness of crowds.)

The evidence of biology is that these seeming alternative theories of correspondence and coherence refer to two reciprocally related qualities of truth as it is given to us to understand.That is, within our “subjective universe,” our biological competence to detect and subsequently manage and act upon information from the world outside our minds, what Jakob von Uexküll (1909/1982) termed our umwelt. [more] The relativism is within us as well as between us, and much like the qualities of organisms that permit one to prevail over a competitor, biology asks not for perfection but for relative advantage. In the natural world, truths, like species, need not be perfect, just better than their competitors. Within organisms, it seems, beliefs enjoy sufficient confidence to be regarded as true because they are the best (most useful or efficient) approximation of truth we have at a given moment.

An additional right versus left hemispheric bias that may be related to the association of right and left cerebral hemispheres with correspondence and coherence, respectively, is the selective activation of structures in the right or left hemisphere when dealing with global versus local attention and processing of visual stimuli (Fink et al. 1996, 1997) [more]





  • “Pragmatic theory of truth refers to those accounts, definitions, and theories of the concept truth that distinguish the philosophies of pragmatism and pragmaticism. The conception of truth in question varies along lines that reflect the influence of several thinkers, initially and notably, Charles Sanders Peirce, William James, and John Dewey, but a number of common features can be identified. The most characteristic features are (1) a reliance on the pragmatic maxim as a means of clarifying the meanings of difficult concepts, truth in particular, and (2) an emphasis on the fact that the product variously branded as belief, certainty, knowledge, or truth is the result of a process, namely, inquiry.” (Wikipedia; last modified 22:32, 28 November 2007)






A work of art is effective as an act of communication to the extent that it is a truthful (valid) representation of an artist’s motivation, affect, or cognition. The evolutionary perspective suggests that initially, art is an act of self-exploration or definition involving communicating between levels of consciousness within an artist. Its validity is essential if the artist wishes to avoid self-deception [more on art to communicate with one’s self]; (although there are contexts in which deception and self-deception are adaptive – Goleman 1985; more on adaptive lies).

In any event, much of our behavior is structured by the possession and pursuit of confidence in the validity of our beliefs. Art involves much exploration at the boundaries of experience and understanding and therefore our confidence in its truthfulness, in its validity, is arguably a necessary quality: “Good art bears true witness” wrote Ezra Pound (1913); “The writer’s first job is not to have opinions but to tell the truth. . . .” wrote Susan Sontag. [quotes].

In subsequent development, as acts of communication between rather than within individuals, works of art must be manifestly truthful if they are to bridge the distance between the artist and the viewer and to evoke the viewer=s receptivity. As Eugene Delacroix put it, painting is only a bridge linking minds (1893).



Art at its best provides new information that catalyzes real or perceived insight in those experiencing it — the artist and/or the viewer. The urgent concern for the stability of their internal environments that all animals share has led to the evolution of elaborate homeostatic mechanisms to maintain a “dynamic stability” that is exquisitely responsive to potential challenges, and therefore to environmental novelty. The experience of novelty and its assimilation or accommodation to existing cognitive structures is arguably the mainspring of cognitive growth (Piaget). In other words, our continuing development depends upon our responsiveness to stimuli which is in large measure a function of the structural characteristics of the nervous system which is in part modified by with past experience. In addition, normal programmed growth and newly accommodated or assimilated stimuli change the structural characteristics that all subsequent stimuli must interact with. [“The adaptive process is one of continuous assimilation of internally mediated consequences of the organism’s action on the environment and the resulting accommodation of these action schemes into the previously formed structure” –Piaget 1980] In this process, stimuli are assessed for salience based on associations with intrinsic and acquired structures. (These associations guide decision making and thus are so important that in their absence, some will be invented – confabulated.) They are the threads that help us see how a specific stimulus is related to our past or potential life experiences. Specific experiences are chained together in more-or-less extended narratives in which one experience may be seen to be the cause or consequence of another, probably adjacent experience – a process vulnerable to flaws in logic, but efficient at organizing information.




Stress is represented by a host of coordinated physiological (including neurobehavioral) mechanisms engineered to cope with real or perceived challenges to real or perceived needs (Greenberg et al. 2002). Stress is also a mainspring of creativity, which like most adaptive processes is energized by moderate stress, but debilitated by excesses (Greenberg 2004). Stress is also arguably essential to the representation of experience in the central nervous system and therefore to actions based upon that knowledge. Percepts judged to be novel are salient because they may present potential challenges to the status quo and thus evoke elements of the physiological stress response. There is an excellent reservoir of information on these relationships, particularly in the light of “sensation-seeking” associated with substance abuse (for example, Dellu et al. 1999).

Elements of the stress response as well as novelty may be more-or-less sought during development to stimulate or maintain a tonic level of stimulation of specific neural areas. Activity of specific elements of the stress response are an important part of normal fetal and postnatal development (Charmandari et al. 2003), however the responsiveness of neural structures to stress hormones during development is ordinarily most obvious when atypical or excessive. For example, the hippocampus is famously sensitive and manifests atrophy of specific dendrites in response to stress (McEwen 1999) and many studies have demonstrated enduring behavioral consequences in the off spring of mothers stressed while pregnant (for example, Clark et al. 1996 With monkeys, Vallee et al. 1997 with rodents). Activation of the stress response can be significantly rewarding and reflect individual reactivity to novelty, including “sensation seeking” which in some environments is easily channeled into dysfunctional behavior such as substance abuse (Piazza et al. 1993).

Novelty and the brain. There is evidence that while novelty is more-or-less attended with the mediation of the prefrontal cortex, the integration of a novel event into one’s internal model of the environment relies on the posterior parietal lobe (Daffner et al. 2003).




The assimilation and accommodation of novel percepts has provided pressure for the development of specializations in the brain for validating apparent correspondence and establishing coherence. Vilayanur Ramachandran (1995) observed that major failures to detect anomalies in body function (anosognosia) are more common following right (but not left) parietal hemisphere damage.

In Ramachandran’s view, while the left hemisphere seems to assemble models and “defend” them with rationalizations, the right hemisphere appears to function as an “anomaly detector.” In other words, the right hemisphere detects incongruities and the left hemisphere tries to make sense of them. This difference between hemispheres has encouraged Ramachandran’s opinion that a damaged right hemisphere is unable to force a change in the belief structure of the left hemisphere. In this scheme, when anomalies detected in the right hemisphere reach a sufficient threshold of urgency, it energizes the left hemisphere’s processing in a way that rationalizes the anomaly or even precipitates a paradigm shift in order to accommodate it.

Additional support for Ramachandran’s speculation that the right hemisphere contains an “anomaly-detector” has found support from experiments on perception in which pictures of more-or-less plausible diagrams were shown to the right or left hemispheres (Smith et al. 2002, 2004). In general, the right hemisphere was superior to the left in identifying pictures that did not conform to any reasonable expectation because (like an optical illusion) they depicted impossible objects,



It is notable that several important neuropsychiatric syndromes besides the remarkable anosognosia described above by Ramachandran (1995) are associated with dysfunctions in the processes of reality-testing (correspondence), story-telling (coherence), or their integration. These include the so-called “limbic epilepsy (in which victims are possessed of “strong feelings of conviction and belief that what one is experiencing at the moment is of the utmost importance or is expressive of the absolute truth,” MacLean 1994, 1997:254); spontaneous confabulation (in which patients have an “inability to adapt thought and behaviour to ongoing reality,”–Schnider 2003); and schizophrenia (for which there is evidence that poor insight into one’s disorder is related to anosognosia, –Lele & Joglekar 1998, as well as evidence that different neural pathways are engaged during novel recognition memory in patients with schizophrenia compared to healthy individuals,” –Crespo-Facorro et al. 2001). [more]



Of the reciprocal interactions between the brain and the stress response the anterior cingulate cortex (ACC) is of particular importance to the manner in which incoming information is attended and compared to resident information of which an individual is more-or-less conscious. Dissonances that may emerge from this comparison are potentially threatening and may thereby evoke elements of the stress response, the hormones of which differentially affect specific brain sites and mechanisms to ameliorate the effects of the stressor. The ACC is one such stress-sensitive site. Two aspects of ACC are unique to higher primates in ways that may affect our confidence in beliefs: spindle cells and the frontal polar cortex (FPC). Spindle cells project to may sites but especially FPC where responses that compensate for “error-detection” are selected and initiated.

While often regarded as part of the limbic system, ACC is more likely a specialized neocortical structure that can also initiate autonomic activity. Autonomic responses, prominent amongst which are the stress responses, are foremost, mechanisms for compensating for real or perceived challenges to homeostasis – but the pathways that invoke . . . have a significant collateral influence on evolved behavioral responses that tend to support the physiological responses – the reflexes of the autonomic nervous system reflect the physiological substrate of affect and its neuro-somatic expression is the external means by which affect is made manifest and can thus be communicated to others. [MacLean (e.g., 1994) makes the useful distinction between affect (subjective feelings) and (following Descartes) emotion (the manifestation of that feeling).]

ACC is thus a leading candidate for the site of integration of emotional and cognitive functions, of which reconciling internal truths to external realities may be particularly prominent. Such reconciliation involves compensating thoughts (which can redirect attention) or actions (which may remove or moderate the stressor).


Stress-moderating actions include the externalization of beliefs in ways that explore their validity, embracing art in both its aesthetic as well as therapeutic sense. It is of interest that the aesthetic experiences associated with the appreciation as well as the creation of art engage elements of the physiological stress response and involve a more or less vivid sense of veracity.

This view of truth, like most of an organism’s critical functions, is one of dynamic relationships between inner and outer worlds, and between valid particulars and plausible generalities. Our relentless ambition to achieve it is, in the words of Schiller, “immer wird, nie ist” (“never is, but is always becoming,” quoted by Thomas Carlyle).




Carlyle, Thomas. Characteristics. The Harvard Classics. 1909–14; Paras. 40

Charmandari, E, Kino, T, Souvatzoglou, E, Chrousos, GP. 2003. Pediatric stress: hormonal mediators and human development. Horm Res. 2003;59(4):161-179. [abstract]

Crespo-Facorro B, Wiser AK, Andreasen NC, O’Leary DS, Watkins GL, Boles Ponto LL, Hichwa RD. 2001. Neural basis of novel and well-learned recognition memory in schizophrenia: a positron emission tomography study. Hum Brain Mapp. 12(4):219-231. [article]

Daffner KR, Scinto LF, Weitzman AM, Faust R, Rentz DM, Budson AE, Holcomb PJ. 2003. Frontal and parietal components of a cerebral network mediating voluntary attention to novel events. J Cogn Neurosci. 15(2):294-313.

Delacroix , Eugene. Journal (1893-1895), cited by Etienne Gilson, 1957:132.

Dellu F, Piazza PV, Mayo W, Le Moal M, Simon H. 1996. Novelty-seeking in rats— biobehavioral characteristics and possible relationship with the sensation-seeking trait in man. Neuropsychobiology. 34(3):136-145. [abstract]

Fink GR, Halligan PW, Marshall JC, Frith CD, Frackowiak RS, Dolan RJ. 1996. Where in the brain does visual attention select the forest and the trees? Nature. 382(6592):626-628.

Fink, GR, JC Marshall, PW Halligan, CD Frith, RSJ Frackowiak, RJ Dolan. 1997. Hemispheric specialization for global and local processing: the effect of stimulus category. Proceedings of the Royal Society: Biological Sciences. 264 (1381): 487 – 494.

Gazzaniga, Michael S. 1992. Nature’s Mind. New York: Basic Books

Greenberg, N, Carr, JA, Summers, JH 2002. Causes and consequences of the stress response. Integrative and Comparative Biology 42(3):508-516. [paper]

Greenberg, N. 2004. Play and the Brain. In: Clements, Rhonda & Fiorentino, Leah, eds. The Child’s Right to Play: A Global Approach. Westport CT: Greenwood Press, pp. 307-327. [paper]

Lele, MV and Joglekar, AS. 1998. Poor insight in schizophrenia: neurocognitive basis. J Postgrad Med. 44(2):50-55. [article]

MacLean, Paul D. 1994. Human nature: Duality or Triality? Politics and the Life Sciences 13(1):107-119. Contribution to a symposium on “The Duality of Human Nature.”

MacLean, Paul D. 1997. The brain and subjective experience: question of multilevel role of resonance. J. Mind and Behavior 18(2-3):247[145]-268[166]. [abstract]

McEwen, Bruce S. 1999. Stress and hippocampal plasticity. Ann. Rev. Neurosci. 1999. 22:105-122. [paper]

Piazza, PV, Deroche, V, Deminiere, JM, Maccari, S, Le Moal, M, Simon, H. 1993. Corticosterone in the range of stress-induced levels possesses reinforcing properties: implications for sensation-seeking behaviors. Proc Natl Acad Sci. 90(24):11738-11742. [abstract] [article pdf]

Pound, Ezra. 1913. The New Freewoman, I:9:163, quoted by By Marina Camboni (2000) “Dora Marsden, Ezra Pound, H.D. and ‘The Art of the Future’”: Part II”

Ramachandran, VS 1995. Anosognosia in parietal lobe syndrome. Consciousness and Cognition. 4:22-51. [abstract]

Rickelman, BL 2004. Anosognosia in individuals with schizophrenia: toward recovery of insight. Issues Ment Health Nurs. 25(3):227-242. [abstract]

Schnider, Armin. 2003. Spontaneous confabulation and the adaptation of thought to ongoing reality. Nature Reviews Neuroscience 4, 662 -671. [summary]

Smith, SD, Tays, WJ, Dixon, MJ, Bulman-Fleming, MB 2002. The right hemisphere as an anomaly detector: evidence from visual perception. Brain Cogn. 48(2-3):574-579. [abstract]

Smith, SD, Dixon, MJ, Tays, WJ, Bulman-Fleming, MB. 2004. Anomaly detection in the right hemisphere: The influence of visuospatial factors. Brain Cogn. 55(3):458-462. [article]

von Uexküll, Jakob (1909/1982)

Vallee, M, Mayo, W, Dellu, F, LeMoal, M, Simon, H, Maccari, S. 1997. Prenatal stress induces high anxiety and postnatal handling induces low anxiety in adult offspring: Correlation with stress-induced corticosterone secretion Journal of Neuroscience 17(7):2626-2636. [article]

Wolford, George, Miller, Michael B., Gazzaniga, Michael. 2000. The Left Hemisphere’s Role in Hypothesis Formation. The Journal of Neuroscience, 20; RC64:1 of 4. [abstract]

Version 5, Nov 6, 2004

folie à duex (“a rare syndrome in which a symptom of (particularly a or belief) is transmitted from one individual to another. Shared visual hallucinations are occasionally reported, that are near, to exact, duplicates. The same syndrome shared by more than one person may be called folie à trois, folie à quatre or even folie à famille. Recent psychiatric classifications refer to the syndrome as induced delusional disorder (DSM-IV) or shared psychotic disorder (ICD-10)”– Wikpedia) , mass hysteria, or the madness of crowds (“‘collective hysteria’ is the name given to a phenomenon due to the manifestation of the same hysterical symptoms by more than one person. It normally begins when an individual shows a hysteric manifestation in front of others who “contagiously” acquire the same symptoms. As examples can be cited cases of accident in which people act “irrationally”, screaming, running in the wrong direction, etc; cases in which a person who is suspected of a crime is caught by a crew and one of the members throws a stone or gives the first kick, and the rest joins the action; etc.” – from Wikpedia).

*originally published as Greenberg, N. 2004. Truth in the Brain: The neuroethology of belief. In: Proc 6th International Research Conference on Consciousness: Qi and Complexity. Roy Ascott, editor. Beijing. pp. 154-160.   





Neil Greenberg received his doctorate from Rutgers University and then moved to Paul D. MacLean’s Laboratory of Brain Evolution and Behavior at the National Institute of Mental Health. While there he was also appointed a Research Associate at Harvard University’s Museum of Comparative Zoology. In 1978, Greenberg joined the faculty of the Department of Ecology and Evolutionary Biology at the University of Tennessee, Knoxville, where he is presently a Professor and Chair of the University Studies (interdisciplinary) Program. He has had several principal investigator and co-principal investigator research and curriculum development grants from the National Institutes of Health, the National Science Foundation, and the Howard Hughes Medical Institute. In 1994 Greenberg was elected a Fellow of the American Association for the Advancement of Science and cited for “exemplary ethological research on the causes and consequences of social behavior and for innovative efforts to illuminate the relations between biology and the humanities.” Greenberg’s core scientific research involves the roles of the basal forebrain and stress physiology in regulating social behavior. His teaching emphasis is physiological ethology, but he also regularly offers the innovative interdisciplinary seminar, “Art and Organism.” Recent lectures have been presented at International Ethology Conferences, the Society for Integrative and Comparative Biology, and the International Brain Research Organization Symposium on “Recent Advances in Understanding the Structure and Function of the Forebrain” at the Max-Planck-Institute.Bottom of Form