Specific reading disability — Strephosymbolia

Orton, Samuel T.

doi:10.1007/bf02653604

Cited by 25 publications

(32 citation statements)

References 5 publications

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“…This type of letter confusion was studied intensively in children by Orton (1928). He observed a delay in the learning of mirror-symmetrical letters and words, as well as several other characteristics involving the establishment of "handedness," in language-handicapped children (Orton, 1928).…”

Section: Invariance For Reflectionsmentioning

confidence: 99%

Psychophysical and Physiological Evidence for Viewer-centered Object Representations in the Primate

1995

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A key question concerning the perception of 3D objects is the spatial reference frame used by the brain to represent them. The celerity of the recognition process could be explained by the visual system's ability to quickly transform stored models of familiar 3D objects, or by its ability to specify the relationship among viewpoint-invariant features or volumetric primitives that can be used to accomplish a structural description of an image. Alternatively, viewpoint-invariant recognition could be realized by a system endowed with the ability to perform an interpolation between a set of stored 2D templates, created for each experienced viewpoint.In the present study we set out to examine the nature of object representation in the primate in combined psychophysical-electrophysiological experiments. Monkeys were trained to recognize novel objects from a given viewpoint and subsequently were tested for their ability to generalize recognition for views generated by mathematically rotating the objects around any arbitrary axis.The perception of 3D novel objects was found to be a function of the object's retinal projection at the time of the recognition encounter. Recognition became increasingly difficult for the monkeys as the stimulus was rotated away from its familiar attitude. The generalization field for novel wire-like and spheroidal objects extended to about ±40° around an experienced viewpoint. When the animals were trained with as few as three views of the object, 120° apart, they could often interpolate recognition for all views resulting from rotations around the same axis.Recordings from inferotemporal cortex during the psychophysical testing showed a number of neurons with remarkable selectivity for individual views of those objects that the monkey had learned to recognize. Plotting the response of neurons as a function of rotation angle revealed systematic view-tuning curves for rotations in depth. A small percentage of the view-selective cells responded strongly for a particular view and its mirror-symmetrical view. For some of the tested objects, different neurons were found to be tuned to different views of the same object; the peaks of the view-tuning curves were 40-50°a part Neurons were also found that responded to the sight of unfamiliar objects or distractors. Such cells, however, gave nonspecific responses to a variety of other patterns presented while the monkey performed a simple fixation task.

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Section: Invariance For Reflectionsmentioning

confidence: 99%

Psychophysical and Physiological Evidence for Viewer-centered Object Representations in the Primate

1995

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“…This phenomenon seems to involve the corpus callosum, the major connecting link between the two hemispheres. One view is that the corpus callosum tends to encode the reverse of LH-learned images (see Bradshaw, Bradley, and Patterson, 1976;Corballis, 1974;Noble, 1966;Orton, 1928).…”

Section: Right Hemisphere Readingmentioning

confidence: 99%

Cognitive Science and the Origin of Lexical Metaphor: A Neurofunctional Shift (NFS) Hypothesis

Haskell¹

2007

THS

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A long-standing and cardinal issue in the cognitive science and humanities research literatures on lexical metaphor is whether figurative language is derived from literal language. In examining this issue, research from a broad spectrum of studies in both cognitive science and the humanities is addressed with particular attention to findings from classicist research on ancient Greek texts, on the cognitive significance of the invention of the Crreek vocalic alphabet. These findings are related to current research on brain hemispheric laterality. It will be suggested that lexical metaphor was originally not a linguistic figure-of speech derived from literal language but only later came to be so conceptualized as the consequence of a neurofunctional shift (NFS) in hemispheric laterality, a shift that was precipitated in part by the invention and adoption of the Crreek vocalic alphabet. It will be further suggested that the prevailing view of metaphor as a linguistic figure of speech is the consequence of an inappropriate cognitive turn that resulted in a superimposition or back scanning of a modern alphabetic-based epistemology on to phenomena originating in a preliterate culture.Metaphor has long been a subject of inquiry by investigators in the humanities Black,

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“…Consistent mirror-reversal errors in identification and reading were called strephosymbolia, meaning "letter turning" [11][12][13][14][15]. Throughout the 20th century, researchers were interested in mirror-reversals in reading and writing as diagnostic features of some disability that predicted good and poor adult readers.…”

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confidence: 99%

“…One theory posited that mirror-reversal errors are perceptual in nature, perhaps having to do with early visual processing of orientation or spatial perception that is underdeveloped or deficient [17][18][19][20][21][22]. Others suggested possible physiological underpinnings [12,23], differences in memory capacity or ability [24,25], differences in eye movements or oculomotor control [26][27][28], and differences in mental imagery ability [29]. Attempts had also been made to connect mirror-reversal errors and reading ability more generally to handedness [27,30,31], dyslexia (e.g., that individuals with dyslexia were more fluent at reading and writing inverted and mirrored text than normals, [32][33][34]), and intelligence [35].…”

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confidence: 99%

On the Legibility of Mirror-Reflected and Rotated Text

et al. 2017

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Abstract:We happened to observe that text that was reflected about either the horizontal or vertical axis was more difficult to read than text that was reflected about first one and then the other, which amounts to a 180-degree rotation. In this article, we review a number of studies that examine the nature of recognizing reflected and inverted letters, and the frequency of mirror reversal errors (e.g., confusing 'b' for 'd') in children and adults. We explore recent ideas linking the acquisition of literacy with the loss of mirror-invariance, not just for text, but for objects in general. We try to connect these various literatures to examine why certain transformations of text are more difficult to read than others for adults. Keywords: mirror-reversal; left-right reversal; reading; reversal errors; mirrored textRecently, one of us held up a page of printed text ( Figure 1A) to their webcam to take a picture. The camera software by default created a mirror-image snapshot (i.e., the text was reflected or mirrored about the vertical axis, Figure 1B) thereby rendering the text virtually illegible. Correcting or undoing this sort of reflection can be trivially accomplished using any number of image processing software packages that include built-in functions such as 'reflect vertical', 'reflect horizontal', 'rotate left', and 'rotate right'. It was with some surprise that when the wrong function was accidentally applied and instead of reflecting along the vertical axis, the image was reflected along the horizontal axis, the text, although now reflected twice, was now more easily legible ( Figure 1D). It is of note that this 'double reflection' is equivalent to a 180 • rotation of the text. With only a few mouse clicks, it was clear that when normally-oriented text is mirror reflected about the horizontal axis it again becomes virtually illegible ( Figure 1C). This brief series of webcam-picture inspired observations demonstrated a basic property of text perception and reading: the legibility of text is reflection variant and rotation invariant.Inspired by these observations, we conducted a review of the corresponding work on the intersection of symmetry, reflections, and the legibility of text. We found a large body of literature on mirror-reading and writing; mirror-reversal errors of single letters in reading, copying, and writing; many studies on perception of normal and mirrored single characters; but only a small number of studies on combinations of geometric transformations including both inversion (up-down mirroring) and reflection (left-right mirroring). In this paper, we review the literature on mirror-reversals and inversions of text and synthesize some recent work and ideas on how representational mirror-invariance not only for letters but also for objects may be lost when someone learns how to read.

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Specific reading disability — Strephosymbolia

Cited by 25 publications

References 5 publications

Psychophysical and Physiological Evidence for Viewer-centered Object Representations in the Primate

Psychophysical and Physiological Evidence for Viewer-centered Object Representations in the Primate

Cognitive Science and the Origin of Lexical Metaphor: A Neurofunctional Shift (NFS) Hypothesis

On the Legibility of Mirror-Reflected and Rotated Text

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