Abstract
This paper connects ideas from twentieth century Gestalt psychology, experiments in vision science, and Maurice Merleau-Ponty’s phenomenology of perception. I propose that when we engage in simple sensorimotor tasks whose successful completion is open, our behavior may be motivated by practical perceptual awareness alone, responding to invariant features of the perceptual field that are invisible to other forms of perceptual awareness. On this view, we see more than we think we see, as evidenced by our skillful bodily behavior.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
Notes
There are documented case studies of neuropathological patients who do not simply perceive good form at all times. Gestalt psychologists Adhemar Gelb and Kurt Goldstein studied a patient who could describe the parts of a visual scene or the sequence of a verbal narrative, but could only guess at the whole they together formed. For instance, when looking at a line drawing of a duck, the patient reported, “there is a dark point, and big like a hand…an uneven circle, like a lung” (Gelb and Goldstein 1917, 15).
Notably, psychophysical isomorphism was not meant to involve “substance” or “quality” (Köhler 1966).
For instance, James J. Gibson posited a psychophysical isomorphism between invariant visual structures of visual perception and invariant structures in the ambient optic array for ecologically situated perceivers (Gibson 1979).
Francis Crick and Cristof Koch’s work on perceptual binding of shape and color may be an instance of temporal psychophysical isomorphism: when a perceiver reports seeing a colored shape, they claim there are synchronous oscillations of neurons correlated with color and shape (Crick and Koch 1990).
I have encountered various explanations for this shift: the rise of computational psychology and neuroscience; the corresponding functionalist theory of mind and its corollary of multiple realizability; the advancement of imaging technology, making “macroscopic” observations of the brain seem both quaint and arbitrary; the worry that looking for psychophysical isomorphs is effectively looking for a homunculus inside the person that entertains the same content as the person herself, making it a kind of Cartesian Materialism or “the view you arrive at when you discard Descartes’s dualism but fail to discard the imagery of a central (but material) theater where ‘it all comes together’” (Dennett 1991, 185). Thus, the psychophysical isomorphism thesis has come to be viewed as either empirically unnecessary (e.g., Sperry 1952) or philosophically suspect (e.g., Dennett 1991).
Though related, Pitts and McCulloch’s size constancy hypothesis should not be confused with the shape constancy phenomenon in Gestalt psychology.
For two-dimensional shapes, the medial axis also can be visualized with water, as border perturbations that produce the medial axis where ripples collide. You might also see the medial axis aesthetically displayed in the converging lines raked into the gravel of a Japanese rock garden. For three-dimensional shapes, the medial axis is best visualized as the ridge formed by a union of cones whose bases sit on the original contour. There are many diverse applications of the medial axis transformation, from collision detection programs to generation of ridgelines for rooftops (Aurenhammer 1991).
Firestone and Scholl chose a different quantitative display of their results than Psotka. Touches appear ‘raw’ in Fig. 5a (similar to Psotka’s presentation) and then as ‘heat maps’ in subsequent figures (Firestone and Scholl's preferred display). Unlike the raw presentation, heat maps are better at depicting multiple touches in the same location. Firestone and Scholl also added interior lines afterwards, for effect. But just as in Psotka’s experiments, subjects were shown only outlines when asked to tap the shape, and the screen was wiped clean after each trial, so to not reveal any previous touches.
For instance, Edmund Husserl observed that a cube viewed from everywhere—all six sides and twelve corners seen all at once—is impossible. In Cartesian Meditations he wrote, “from my body’s point of view, I never see the six faces of the cube as equal, even if it is made of glass” (Husserl 1999, 209–211). To see a cube is for parts of it to be occluded from view, both in time and in space. Maurice Merleau-Ponty repeated this point in Phenomenology of Perception. “To be able to conceive of the cube, we take up a position in space, sometimes on its surface, sometimes inside it, and sometimes outside of it, and from then on we see it in perspective. The cube with six equal sides is not merely invisible, but is even inconceivable; this is the cube such as it would be for itself; but the cube is not for itself, since it is an object” (Merleau-Ponty 2012, 210).
Perceptual presence of absence appears repeatedly in the phenomenological tradition (e.g., Husserl 2001; Sartre 1943; Merleau-Ponty 2012). Samuel Todes (2001), Alva Noë (2004), and Sean Kelly (2005) have recently developed views of perceptual presence of absence influenced by these early phenomenological accounts, and especially by Merleau-Ponty’s work.
In Gestalt Psychology, Köhler criticized a view he called (somewhat confusingly) “the constancy hypothesis.” Not to be confused with the size constancy hypothesis or the shape constancy phenomenon, the constancy hypothesis posits a one-to-one relation between sensation (which is directly correlated with sensory stimulation) and perception (which is not) (Köhler 1975). Notably, Merleau-Ponty took up Köhler’s criticism of the constancy hypothesis in Phenomenology of Perception. The two theorists agreed that the content of perception outstrips the content of sensation, but for each for different reasons (e.g., Merleau-Ponty rejected both the existence of “sensations” and the determinacy of “perception”) (Merleau-Ponty 2012).
As already mentioned in footnote 9, we can see an entire two-dimensional object in space but never an entire three-dimensional object in space. We might call this occlusion by space. Occlusion by time is another matter, and altogether unavoidable, insofar as our perception of all objects occurs within a moving horizon of past, present, and future.
Husserl claimed that because the body occupies space (and moves through it), the body is the condition of possibility of the spatiality of objects in the perceptual field (e.g., Husserl 1973). Though Merleau-Ponty agreed, he also seemed to be making a different point—that skillful bodily activity structures the spatiality of the perceptual field. Whether Merleau-Ponty also wished to make the Husserlian point is not an issue I address here. We may look instead to Dan Zahavi for discussions of Husserl’s view on the relation between the body and perceptual space in his book Self Awareness and Alterity (Zahavi 1999) and Merleau-Ponty’s understanding thereof in “Merleau-Ponty on Husserl: A Reappraisal” (Zahavi 2002).
Egocentric space should not be confused with bodily space. For example, in egocentric space, a perceiver standing in front of two equidistant objects would represent them differently in terms of right/left or up/down. In contrast, in bodily space, a perceiver standing in front of two equidistant objects may see one as closer or larger than the other, depending on her motor intention to grasp one but not the other. In “Skillful Action in Peripersonal Space,” I describe Merleau-Ponty’s distinction between objective space and bodily space in greater detail (Jackson 2014).
It is possible to imagine a subject who, through some cognitive activity, dependably identifies the medial axis of shapes—perhaps someone preternaturally good at visualizing grassfire transformations. Further suppose her reliability never diminishes, even as the shapes become increasingly complex or occluded. Nevertheless, her cognitive way of identifying the medial axis would not be the same as the way that subjects in these experiments responded to the medial axis.
Even Hung, Carlson and Connor wish to qualify their findings: the areas involved in possible medial axis transformations are “so small that they require fMRI-based targeting for neural recording experiments, so it is unlikely that we sampled extensively from them” (Hung et al. 2012, 1110).
References
Aurenhammer, F. (1991). Voronoi diagrams: a survey of fundamental geometric data structure. Computing Surveys (Association of Computing Machinery), 23(3), 345–405.
Blum, H. (1967). A transformation for extracting new descriptors of shape. In W. Whaten-Dunn (Ed.), Models for the Perception of Speech and Visual Form (pp. 362–380). Cambridge: MIT Press.
Blum, H. (1973). Biological shape and visual science. Journal of Theoretical Biology, 38, 205–287.
Crick, F., & Koch, C. (1990). Towards a neurobiological theory of consciousness. Seminars in the Neurosciences, 2, 263–275.
Crick, F., & Koch, C. (2003). A framework for consciousness. Nature Neuroscience, 6, 119–126.
Dennett, D. (1969). Content and Consciousness. New York: Routledge.
Dennett, D. (1991). Consciousness Explained. Boston: Back Bay Books.
Dennett, D. (1998). No bridge over the stream of consciousness. Behavioral and Brain Sciences, 21(6), 753–754.
Epstein, W., & Hatfield, G. (1994). Gestalt psychology and the philosophy of mind. Philosophical Psychology, 7(2), 163–181.
Firestone, C., & Scholl, B. (2014). “Please Tap the Shape, Anywhere You Like”: shape skeletons in human vision revealed by an exceedingly simple measure. Psychological Science, 25(2), 377–386.
Gelb, A., & Goldstein, K. (1917). Psychologische Analysen hirnpathologischer Fälle auf Grund von Untersuchungen Hirnverletzer. Zeitschrift für die gesamte Neurologie und Psychiatrie, 41(1), 1–142.
Gibson, J. J. (1979). The Ecological Approach to Visual Perception. Hillsdale: Lawrence Erlbaum Associates.
Henle, M. (1984). Isomorphism: setting the record straight. Psychological Research, 46, 317–327.
Hochberg, J. (1964). Perception. Englewood: Prentice-Hall.
Hung, C.-C., Carlson, E., & Connor, C. (2012). Medial axis shape coding in macaque inferotemporal cortex. Neuron, 74, 1099–1113.
Husserl, E. (1901/2001). Logical Investigations, Volume 2 (trans: Findlay, J. N.). New York: Routledge.
Husserl, E. (1907/1973). Thing and Space, Lectures of 1907 (trans: Rojcewicz, R.). The Hague: Martinus Nijhoff.
Husserl, E. (1929/1999). Cartesian Meditations (trans: Cairns, D.). The Hague: Martinus Nijhoff.
Jackson, G. (2014). Skillful action in peripersonal space. Phenomenology and the Cognitive Sciences, 13(2), 313–334.
Kelly, S. (2005). Seeing Things in Merleau-Ponty. In T. Carman & M. Hansen (Eds.), Cambridge Companion to Merleau-Ponty (pp. 74–110). New York: Cambridge University Press.
Koffka, K. (1963/1935). The Principles of Gestalt Psychology. New York: Harbinger.
Köhler, W. (1966/1938). The Place of Value in a World of Facts. New York: Liveright.
Köhler, W. (1975/1947). Gestalt Psychology. New York: Liveright.
Kovács, I., & Julesz, B. (1994). Perceptual sensitivity maps within globally defined visual shapes. Nature, 370, 644–646.
Kubovy, M., & Psotka, J. (1976). The predominance of seven and the apparent spontaneity of numerical choices. Journal of Experimental Psychology: Human Perception and Performance, 2(2), 291–294.
Lee, T. S., Mumford, D., Romero, R., & Lamme, V. (1998). The role of the primary visual cortex in higher level vision. Vision Research, 38, 2429–2454.
Lehar, S. (2003). Gestalt isomorphism and the primacy of subjective conscious experience: a gestalt bubble model. Brain and Behavioral Sciences, 26(4), 375–408.
Lescroart, M., & Biederman, I. (2013). Cortical representation of medial axis structure. Cerebral Cortex, 23, 629–637.
Merleau-Ponty, M. (1942/1963) Structure of Behavior (trans: Fisher, A. L.). Boston: Beacon Press.
Merleau-Ponty, M. (1945/2012.) Phenomenology of Perception (trans: Landes, D.). New York: Routledge.
Müller, G. (1896). Zur Psychophysik der Gesichtsempfindungen. Zeitschrift für Psychologie und Physiologie der Sinnesorgane, 10, 1–82.
Neisser, U. (1976). Cognition and Reality: Principles and Implications of Cognitive Psychology. New York: Freeman.
Noë, A. (2004). Action in Perception. Cambridge: MIT Press.
O’Regan, K. (1992). Solving the “real” mysteries of visual perception: the world as an outside memory. Canadian Journal of Psychology, 46, 461–488.
Pessoa, L., Thompson, E., & Noe, A. (1998). Finding out about filling in. Behavioral and Brain Sciences, 21(6), 723–802.
Pitts, W., & McCulloch, W. (1947). How we know universals: the perception of auditory and visual forms. The Bulletin of Mathematical Biophysics, 9(3), 127–147.
Psotka, J. (1978). Perceptual processes that may create stick figures and balance. Journal of Experimental Psychology: Human Perception and Performance, 4(1), 101–111.
Rock, I. (1956). The orientation of forms on the retina and in the environment. American Journal of Psychology, 69, 513–528.
Sartre, J.-P. (1943/1984). Being and Nothingness (trans: Barnes, H.). New York: Washington Square Press.
Scheerer, E. (1994). Psychoneural isomorphism: historical background and current relevance. Philosophical Psychology, 7, 183–210.
Siddiqi, K., Tresness, K., & Kimia, B. (1996). Parts of visual form: psychophysical aspects. Perception, 25, 399–424.
Sperry, R. (1952). Neurology and the mind-brain problem. American Scientist, 40(2), 291–312.
Spillmann, L., & Ehrenstein, W. (1996). From neuron to gestalt: mechanisms of visual perception. In R. Greger & U. Windhorst (Eds.), Comprehensive Human Physiology, Volume 1 (pp. 861–893). Heidelberg: Springer.
Stadler, M., & Kruse, P. (1994). Gestalt theory and synergetics: from psychophysical isomorphism to holistic emergentism. Philosophical Psychology, 7(2), 211–216.
Todes, S. (2001). Body and World. Cambridge: MIT Press.
Wang, X., & Burbeck, C. (1998). Scaled medial axis representation: evidence from position discrimination task. Vision Research, 38, 1947–1959.
Wertheimer, M. (2012/1912). Experimental studies on seeing motion. In L. Spillman (Ed.), On Perceived Motion and Figural Organization (pp. 1-92). Cambridge: MIT Press.
Zahavi, D. (1999). Self-Awareness and Alterity. Evanston: Northwestern University Press.
Zahavi, D. (2002). Merleau-Ponty on Husserl: a reappraisal. In T. Toadvine & L. Embree (Eds.), Merleau-Ponty’s Reading of Husserl (pp. 3–29). Boston: Kluwer.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jackson, G.B. Seeing what is not seen. Phenom Cogn Sci 17, 503–519 (2018). https://doi.org/10.1007/s11097-017-9524-0
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11097-017-9524-0