Spatial Asymmetries in Tactile Discrimination of Line Orientation: A Comparison of the Sighted, Visually Impaired, and Blind

Thresholds for tactile discrimination of stimulus orientation discrepancy from standard or referent vertical, horizontal, and diagonal orientations were determined for sighted, visually impaired, and blind subject groups. The stimuli were presented to the ventral distal portion of the tip of the subject's left index finger via an Optacon. Although the subject groups did not differ in overall discrimination accuracy, for each group the deviations from vertical and horizontal standard orientations were discriminated reliably more accurately than the deviations from standard diagonals, ie the oblique effect was obtained. The bases for this tactual spatial anisotropic effect appear to reflect both sensory—neurological and experiential factors.

[1]  F. Campbell,et al.  Electrophysiological evidence for the existence of orientation and size detectors in the human visual system , 1970, The Journal of physiology.

[2]  G C Gilmore,et al.  Multidimensional letter similarity derived from recognition errors , 1979, Perception & psychophysics.

[3]  E C Lechelt,et al.  Spatial Anisotropy in Intramodal and Cross-Modal Judgments of Stimulus Orientation: The Stability of the Oblique Effect , 1980, Perception.

[4]  Peter Bryant,et al.  Perception and Understanding in Young Children , 1975 .

[5]  S Appelle,et al.  Effect of Modality-Specific Experience on Visual and Haptic Judgment of Orientation , 1985, Perception.

[6]  J. Jastrow.  Studies from the University of Wisconsin: On the Judgment of Angles and Positions of Lines , 1892 .

[7]  S. Appelle.  Perception and discrimination as a function of stimulus orientation: the "oblique effect" in man and animals. , 1972, Psychological bulletin.

[8]  L. E. Krueger,et al.  Letter Search by Braille Readers: Implications for Instruction , 1983 .

[9]  J. Moorhouse,et al.  Touch-perception thresholds in blind diabetic subjects in relation to the reading of Braille type. , 1969, The New England journal of medicine.

[10]  J. Atkinson.  The effect of size, retinal locus, and orientation on the visibility of a single afterimage , 1972 .

[11]  K. V. Wilson.  The sampling distribution of conservational, conservative and corrected F-ratios in reapeated measures designs wiht heterogeneity of covariance † , 1975 .

[12]  B. Frost,et al.  Human Visual Ecology and Orientation Anisotropies in Acuity , 1973, Science.

[13]  P W Davidson,et al.  Differential effects of task memory demand on haptic matching of shape by blind and sighted humans. , 1974, Neuropsychologia.

[14]  R. Mansfield,et al.  Neural Basis of Orientation Perception in Primate Vision , 1974, Science.

[15]  S Appelle,et al.  Eliminating the Haptic Oblique Effect: Influence of Scanning Incongruity and Prior Knowledge of the Standards , 1986, Perception.

[16]  Irwin Altman,et al.  Behaviour and perception in strange environments. , 1977 .

[17]  T. Wake.  Effect of Orientation on Tactile Sensitivity of Blind Person (宇都宮大学教養部発足15周年記念号) , 1982 .

[18]  Peter Ning,et al.  Electrocutaneous stimulation III. The perception of temporal order , 1982, Perception & psychophysics.

[19]  J C Craig,et al.  Some factors affecting tactile pattern recognition. , 1983, The International journal of neuroscience.

[20]  James C. Bliss,et al.  Optical-to-Tactile Image Conversion for the Blind , 1970 .

[21]  R Vogels,et al.  Decision factors affecting line orientation judgments in the method of single stimuli , 1986, Perception & psychophysics.

[22]  E. Lechelt,et al.  Perceptual orientational asymmetries: A comparison of visual and haptic space , 1976 .

[23]  E. Essock.  The Oblique Effect of Stimulus Identification Considered with Respect to Two Classes of Oblique Effects , 1980, Perception.

[24]  B Jenkins,et al.  Orientational anisotropy in the human visual system , 1985, Perception & psychophysics.

[25]  R Held,et al.  Orientational anisotropy in infant vision , 1975, Science.