Stephen Kosslyn

American psychologist

Stephen Michael Kosslyn (born 1948) is an American psychologist, neuroscientist, Founding Dean and Chief Academic Officer of the Minerva Schools at KGI (the Keck Graduate Institute), author and educator who specializes in the fields of cognitive psychology and cognitive neuroscience.

Portrait of Stephen M.Kosslyn, 2021


  • During the late 1970s and early 1980s there was vigorous debate about the nature of visual mental imagery. One position (championed primarily by Pylyshyn, 1973, 1981) held that representations that underlie the experience of mental imagery are the same type as those used in language; the other position (which my colleagues and I supported, e.g., Kosslyn, 1980, 1994) held that these representations serve to depict, not describe, objects. The debate evolved over time... but always centred on the nature of the internal representations that underlie the experience of visualisation.
    • Stephen M. Kosslyn, "Mental images and the brain." Cognitive Neuropsychology 22.3-4 (2005): p. 333
  • We must begin by distinguishing between visual mental imagery and visual perception: Visual perception occurs while a stimulus is being viewed, and includes functions such as visual recognition (i.e., registering that a stimulus is familiar) and identification (i.e., recalling the name, context, or other information associated with the object). Two types of mechanisms are used in visual perception: “bottom-up” mechanisms are driven by the input from the eyes; in contrast, “top-down” mechanisms make use of stored information (such as knowledge, belief, expectations, and goals). Visual mental imagery is a set of representations that gives rise to the experience of viewing a stimulus in the absence of appropriate sensory input. In this case, information in memory underlies the internal events that produce the experience. Unlike afterimages, mental images are relatively prolonged.
    • Stephen M. Kosslyn, "Mental images and the brain." Cognitive Neuropsychology 22.3-4 (2005): p. 334
  • But because of the way in which depictions represent, there is a correspondence between parts and spatial relations of the representation and those of the object; this structural mapping, which confers a type of resemblance, underlies the way images convey specific content. In this respect images are like pictures. Unlike words and symbols, depictions are not arbitrarily paired with what they represent.
    • Stephen M. Kosslyn, ‎William L. Thompson, ‎Giorgio Ganis (2006), The Case for Mental Imagery. p. 44; Cited in: Michael R. W. Dawson (2013). Mind, Body, World: Foundations of Cognitive Science. p. 108

Image and Mind. 1980


Stephen Kosslyn. Image and Mind. 1980.

  • A mental image occurs when a representation of the type created during the initial phases of perception is present but the stimulus is not actually being perceived; such representations preserve the perceptible properties of the stimulus and ultimately give rise to the subjective experience of perception.
    • p. 6
  • These organizational processes result in our perceptions being structured into units corresponding to objects and properties of objects. It is these larger units that may be stored and later assembled into images that are experienced as quasi-pictorial, spatial entities resembling those evoked during perception itself.... It is erroneous to equate image representations with mental photographs, since this would overlook the fact that images are composed from highly processed perceptual encodings.
    • p. 19
  • Like pictures, images seem to depict information about interval spatial extents. The scanning experiments support the claim that portions of images depict corresponding portions of the represented objects, and that the spatial relations between portions of the image index the spatial relations between the corresponding portions of the imaged objects.
    • p. 51
  • Even if it were clear what was meant, this sort of treatment would seem closer to describing what is taking place than to explaining it. I do not want to deny the value of describing a phenomenon; rich descriptions facilitate theorizing, and there is no more astute observer than Piaget. But in my view explanations of cognitive phenomena should specify the ways in which functional capacities operate. Piaget and Inhelder’s account is more on the level of intentionality, and hence is open to multiple interpretations at the level of the function of the brain. The do not specify how interiorized imitation operates, nor have they specified the format or content of the image. This level of discourse will never produce process adequacy, and hence seems of limited value.
    • p. 411
  • It is hard to define something one knows little about
    • p. 469
  • Physics seems to have done reasonably well in studying electrons, although there is not to this day a precise definition of this term.
    • p. 470

Better PowerPoint (R), 2010


Stephen M. Kosslyn, Better PowerPoint (R): Quick Fixes Based On How Your Audience Thinks. 2010

  • Mr. Magoo Rule: Text and graphics must be easily distinguished and recognized. Don ́t make your audience members feel like the vision challenged Mr. Magoo—viewers of an electronic slideshow should not risk eyestrain!
    • p. 11
  • Resist the temptation to use special effects. Think about science fiction movies with lots of special effects: If you notice that special effects are special effects, they will fail.
    • p. 24
  • Bullets are a convenient way to present the separate elements of a list. However, bullets are a bit like salt—often essential to bring out the best, but distasteful if overdone.
    • p. 54
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