Visual Imagery Selectively Reduces Vernier Acuity

Mental imagery interferes with perception. This, an example of the ‘Perky effect’, was studied for vernier acuity. Mean accuracy for reporting the offset of vertical line targets declined from 80% to 65% when subjects were requested to imagine vertical lines near fixation. Images of horizontal lines or of a grey mist in the fixation region lowered accuracy to a similar extent. However, accuracy was barely affected when the image was requested 1.5 deg or more from the target. The Perky effect remained strong for at least 4 s after an instruction to ‘clear’ the image away. The results were not due to imagery-induced changes in fixation, pupil diameter, or accommodation, or (at least primarily) to central attentional or decisional factors. Rather, imagery produces a local, pattern-insensitive, and relatively long-lasting reduction in visual sensitivity. The sensitivity loss may be mimicked by a 0.24 log unit reduction in target energy.

[1]  R. Finke,et al.  Theories relating mental imagery to perception. , 1985, Psychological bulletin.

[2]  A. Reeves,et al.  Visual imagery lowers sensitivity to hue-varying, but not to luminance-varying, visual stimuli , 1981, Perception & psychophysics.

[3]  U. T. Keesey.  Effects of involuntary eye movements on visual acuity. , 1960, Journal of the Optical Society of America.

[4]  D G Pelli,et al.  Uncertainty explains many aspects of visual contrast detection and discrimination. , 1985, Journal of the Optical Society of America. A, Optics and image science.

[5]  A. Reeves,et al.  Interruption of Dot Processing by a Backward Mask , 1983, Perception.

[6]  Cheves West Perky.  An Experimental study of imagination. , 1910 .

[7]  M. Farah,et al.  Psychophysical evidence for a shared representational medium for mental images and percepts. , 1985, Journal of experimental psychology. General.

[8]  A Reeves,et al.  Visual imagery in backward masking , 1980, Perception & psychophysics.

[9]  P. Sheehan,et al.  Reliability of a Short Test of Imagery , 1967, Perceptual and motor skills.

[10]  M. J. Intons-Peterson,et al.  Imagery paradigms: how vulnerable are they to experimenters' expectations? , 1983, Journal of experimental psychology. Human perception and performance.

[11]  Jack Broerse,et al.  Imagined lines fail to induce contour masking , 1972 .

[12]  W S Geisler,et al.  Physical limits of acuity and hyperacuity. , 1984, Journal of the Optical Society of America. A, Optics and image science.

[13]  V. Dreyer,et al.  Visual acuity. , 1974, Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde.

[14]  S. J. Segal,et al.  Influence of imaged pictures and sounds on detection of visual and auditory signals. , 1970, Journal of experimental psychology.

[15]  Gerald Westheimer,et al.  Temporal and spatial interference with vernier acuity , 1975, Vision Research.

[16]  W. Larkin,et al.  Frequency-response characteristic of auditory observers detecting signals of a single frequency in noise: the probe-signal method. , 1968, The Journal of the Acoustical Society of America.

[17]  R. Shepard,et al.  Functional representations common to visual perception and imagination. , 1978, Journal of experimental psychology. Human perception and performance.

[18]  Benjamin Wallace,et al.  Creation of the horizontal-vertical illusion through imagery , 1984 .

[19]  G. Westheimer,et al.  Visual acuity as a function of exposure duration. , 1973, Journal of the Optical Society of America.

[20]  M. J. Peterson,et al.  Visual detection and visual imagery. , 1974, Journal of Experimental Psychology.

[21]  S. J. Segal,et al.  The Perky Effect Revisited: Blocking of Visual Signals by Imagery , 1969 .

[22]  F. Campbell,et al.  Vernier acuity: interactions between length effects and gaps when orientation cues are eliminated. , 1985, Spatial vision.

[23]  E. Hilgard,et al.  Visual imagery and the discrimination of differences between altered pictures simultaneously and successively presented. , 1975, British journal of psychology.

[24]  C. A. Burbeck,et al.  Exposure-duration effects in localization judgments. , 1986, Journal of the Optical Society of America. A, Optics and image science.

[25]  M J Farah,et al.  Perceptual interference and facilitation with auditory imagery , 1983, Perception & psychophysics.

[26]  E. Scheerer,et al.  Two Visual Stores and Two Processing Operations in Tachistoscopic Partial Report , 1976, The Quarterly journal of experimental psychology.

[27]  Gillian Rhodes,et al.  Imagery effects on early visual processing , 1985, Perception & psychophysics.

[28]  R. Finke,et al.  The functional equivalence of mental images and errors of movement , 1979, Cognitive Psychology.

[29]  E W Scripture.  MEASURING HALLUCINATIONS. , 1896, Science.

[30]  A. Reeves,et al.  Effects of Visual Imagery on Visual Sensitivity and Pupil Diameter , 1973, Perceptual and motor skills.

[31]  C. Eriksen,et al.  Temporal course of selective attention. , 1969, Journal of experimental psychology.

[32]  Lester A. Lefton,et al.  Metacontrast: A review. , 1973 .

[33]  H. Barlow.  Temporal and spatial summation in human vision at different background intensities , 1958, The Journal of physiology.

[34]  S. McKee,et al.  Visual acuity in the presence of retinal-image motion. , 1975, Journal of the Optical Society of America.

[35]  Daniel J. Weintraub,et al.  The parallel-less Poggendorff: Virtual contours put the illusion down but not out , 1972 .

[36]  G. Sperling,et al.  Attention gating in short-term visual memory. , 1986, Psychological review.

[37]  B. Amblard,et al.  Backward and forward masking in the perception of cutaneous stimuli , 1973 .

[38]  Oswald Külpe.  Ueber die Objectivirung und Subjectivirung von Sinneseindrücken , 1902 .

[39]  S. Kosslyn,et al.  Mental imagery acuity in the peripheral visual field. , 1980, Journal of experimental psychology. Human perception and performance.