Neuropsychological Model – David Lewis-Williams and Thomas Dowson’s neuropsychological model, set out in their Current Anthropology article “The Signs of All Times: Entoptic Phenomena in Upper Paleolithic Art” (1988), proposes three loosely defined and fluid stages in the progression of trance. In the first, “entoptics,” stage, subjects spontaneously perceive entoptics, classified into six principal types: grids, lines, dots, zigzags, catenary curves, and filigrees. In the second, “construal,” stage, subjects attempt to make sense of these geometric shapes and construe them into culturally recognizable forms: a Western subject may perceive an entoptic grid and may construe it into the string-grid of a tennis racket, while a San (Bushman) shaman may construe an entoptic grid into the shape of the honeycomb associated with powerful bee spirithelpers. In the third, “entoptics and iconics,” stage, subjects may perceive both entoptic and culturally derived iconic imagery. In this latter stage also, when the trance is at its most intense, subjects may feel they are a part of their imagery: in one neuropsychological experiment, a subject thought of a fox and instantly became a fox; the therianthropes (composite human–animal images) in San rock art and European Paleolithic cave art may be associated with such experiences. In all three stages, imagery is subject to seven principles of visual transformation: replication, fragmentation, integration, superpositioning, juxtapositioning, reduplication, and rotation.
Lewis-Williams and Dowson applied their model to European Paleolithic cave art, which is without directly relevant ethnography, and demonstrated the strength of their model by applying it to two rock art traditions that are known ethnographically to be linked to shamanistic practices: San rock art, on which their earliest research is based, and rock art imagery from the Coso range in far western North America (developed by David Whitley). Since its dissemination in published form, the neuropsychological model has been applied to a vast corpus of imagery as diverse as northwest European megalithic art (by Jeremy Dronfield), Aboriginal Australian rock art, and British Iron Age coinage. Critics such as Paul Bahn question the value of a model that appears to sweepingly interpret all artistic traditions with geometric images according to shamanistic trances. Proponents of the model contest its indiscriminate use also, arguing that too often it is applied uncritically in a search for entoptics. Such a search for similarities has a misleading premise—equating entoptics with shamanism—and neglects to account for trance stages 2 and 3, the principles of transformation steering the perception of imagery, and the heterogeneity of rock art (and other visual culture) and shamanism.
More recently, a more rigorous and critical approach to neuropsychology and shamanisms in rock art research has developed. As a matter of course, the neuropsychological model must be applied in its entirety in order to retain its integrity and effectiveness as a valuable interpretative tool: identification of endogenous forms, principles of transformation of visual imagery, and specific cultural contexts of iconic images. Furthermore, Dronfield has reformulated the loosely classified “entoptics” or “subjective visual phenomena” into specific “endogenous diagnostic” categories. Moreover, a “shamanistic approach” has been theorized by Dowson that not only embraces the diversity and difference of shamanisms and rock art but also has wider implications for how shamans are understood anthropologically and archaeologically, particularly in light of the new animism. This refinement of approach suggests that while an “entoptics” bandwagon has passed, the shamanistic interpretation remains at the forefront of rock art research.