Abstract: This experiment involved the question of where human observers look in a picture. The results indicated that observers fixate earlier, more often, and with longer durations on objects that have a low probability of appearing in a scene (e.g., an octopus in a farm scene) than on objects that have a high probability of appearing (e.g., a tractor in a farm scene). These findings (a) imply a role of cognitive factors in peripheral visual processing and (b) suggest a possible relationship between the nature of information initially acquired from a picture and subsequent recognition memory for that picture.

Abstract: Having rejected the picture theory of natural perception we can make a start on picture perception. To see the environment is to extract information from the ambient array of light. What is it, then, to see a picture of something? The information in ambient light does not consist of forms and colors but of invariants. Is it implied that the information in a picture does not consist of forms and colors but of invariants? That sounds very odd, for we suppose that a picture is entirely composed of forms and colors. The kind of vision we get from pictures is harder to understand than the kind we get from ambient light, not easier. It should be considered at the end of a treatise on perception, not at the beginning. It cannot be omitted, for pictures are an essential part of human life as much as words. They are deeply puzzling and endlessly interesting. What are pictures and what do they do for us?

Abstract: : Visual perception was investigated using spatial filters that are constrained by biological data. This report has four major parts: (1) a theoretical background to Fourier analysis; (2) a review of the literature relating to the spatial filtering characteristics of mammalian visual systems; (3) visual information processing in terms of spatial filtering; (4) the relating of contrast sensitivity to the identification of complex objects. The common denominator to all the investigations is spatial filtering. The major goal of the dissertation was the attempt to explain certain aspects of visual perception using a single concept: filtering. (Author)

Abstract: I Comparative Studies of Effects of Experience on Perception.- References.- 1 Altered Early Environment: Effects on the Brain and Visual Behavior.- 1. Advantages of Visual System Analysis.- 2. Feature Detectors: A Model of Visual Processing.- 2.1. Detectors in the Adult.- 2.2. Detectors in the Newborn.- 3. Altered Early Environments: A Means of Assessing Innate vs. Experiential Factors.- 3.1. Monocular and Binocular Deprivation.- 3.2. X, Y, and W Afferents: An Addition to the Model.- 3.3. Effect of Visual Deprivation on X, Y, and W Cells.- 3.4. Alternating Monocular Occlusion and Surgically Induced Squint.- 3.5. Early Selective Visual Experience.- 4. Conclusions.- 5. References.- 2 Effect of Early Visual Experience on the Development of Certain Perceptual Abilities in Animals and Man.- 1. Historical Perspective.- 2. New Evidence.- 2.1. Properties of Visual Cortical Cells in the Neonate.- 2.2. Effects of Selective Visual Deprivation.- 3. Implications for Perception.- 3.1. Modification of Vision in Animals by Abnormal Early Visual Input.- 3.2. Modification of Vision in Humans by Abnormal Early Visual Input.- 4. Conclusions.- 5. References.- 3 Depth Perception and Experience.- 1. Introduction.- 2. The Human Infant.- 3. The Unlearned Nature of Depth Perception.- 3.1. Precocial Species.- 3.2. Altricial Species.- 4. Studies of Experience with Animals.- 4.1. Genetic Ecological Experience.- 4.2. Reared in "Flat," "Cliff," or "Enriched" Environments, or over Visual Depths.- 4.3. Visual Deprivation.- 4.4. Visuomotor Experience.- 4.5. "Mothering".- 4.6. Improvement and Experience.- 5. Discussion and Conclusion.- 5.1. Adaptation and Ecology.- 5.2. Psychology and Ethology.- 5.3. Measures of Depth Perception.- 5.4. The Perceptual Response.- 5.5. Sensorimotor Effects.- 5.6. Plasticity and Pervasiveness.- 5.7. Plasticity and Phylogeny.- 6. References.- 4 Auditory Environment and Vocal Development in Birds.- 1. Introduction.- 2. Vocal Development Independent of Auditory Environment.- 3. Birdsong.- 4. Effects of Auditory Isolation on Song Development.- 5. Predisposition to Learn Conspecific Song.- 6. Cues for Song Recognition.- 7. Critical Period of Song Learning.- 8. Role of Auditory Feedback.- 9. Concept of a Song Template.- 10. Concluding Remarks.- 11. References.- II Effects of Prolonged Experience on Human Perception.- References.- 5 Role of Linguistic Experience in the Perception of Speech.- 1. Introduction.- 2. The Speech Code.- 3. The Categorical Perception Phenomenon.- 4. Some Recent Research on Categorical Perception.- 4.1. Is Categorical Perception Unique to Speech?.- 4.2. Is Categorical Perception of Speech Unique to Humans?.- 5. Categorical Perception and Linguistic Experience.- 5.1. Cross-Language Studies of Voice Onset Time.- 5.2. Cross-Language Studies of Place of Articulation.- 5.3. Within-Language Studies.- 5.4. Laboratory Training Studies.- 6. Development of Phonetic Perception.- 6.1. Cross-Language Studies with Infants.- 6.2. Developmental Studies of Phonetic Perception.- 6.3. Critical Periods in Perceptual Development.- 6.4. Relationship of Perception and Production.- 6.5. Summary of the Developmental Research.- 7. Conclusions and Directions for Future Research.- 8. References.- 6 Cultural Effects on Pictorial Perception: How Many Words Is One Picture Really Worth?.- 1. Introduction.- 2. Trivial Projective Ambiguity: Fully Colored and Detailed Pictures.- 3. Conversion of Colored Pictures to Black and White.- 4. Nontrivial Projective Ambiguity: Outline Drawings.- 5. Recognition of Pictured Objects in Line Drawings.- 6. Embedded Figures Tests.- 7. Pictorial Depth Perception.- 8. Coexistence of Flatness and Depth Information in Pictures.- 9. Use of Conventional Symbols in Art.- 10. Cultural and Historical Options in Depiction.- 11. Summary and Future Directions.- 12. References.- 7 Visual Impairment and the Development of Perceptual Ability.- 1. Definition, Prevalence, Etiology.- 2. Concept Development.- 3. Tangible Graphics.- 4. Mobility.- 5. Alternatives to Visual Reading.- 5.1. Reading Large Print.- 5.2. Reading Braille.- 5.3. Reading by Listening.- 5.4. Machine Translation of the Print Code.- 6. Conclusions.- 7. References.- 8 Perceptual Effects of Deafness.- I. Introduction.- 2. Visual Perception and Deafness.- 2.1. Ocular Defects.- 2.2. Visual Test Performance and the Deficiency Hypothesis.- 2.3. The Compensation Hypothesis.- 2.4. Visual Memory for Simultaneous and Sequential Stimuli.- 2.5. Verbal Mediation in Perception and Cognition.- 2.6. Social Perception.- 3. Tactual Perception.- 4. Visual and Tactile Displays for Speech Perception.- 4.1. Visual Aids for Speech Perception.- 4.2. Tactile Aids for Speech Perception.- 5. Conclusions.- III Effects of Short-Term Experience on Human Perception.- References.- 9 Effects of Exposure to Spatially Distorted Stimuli.- 1. Introduction.- 2. Effects of Asymmetrical Stimulation.- 2.1. The Tilt Aftereffect.- 2.2. Kinesthetic Asymmetry.- 3. Effects of Distorting Frames of Reference.- 4. Perceptual Polarity: Effects of Reversed Frame of Reference.- 5. Effects of Discordant Sensory Stimulation.- 5.1. Effects of Intrasensory Discordance on Spatial Judgments.- 5.2. Effects of Intersensory Discordance on Spatial Judgments.- 5.3. Effects of Motorsensory Discordance on Spatial Judgments.- 5.4. Sensorimotor Consequences of Discordant Stimulation.- 5.5. Site of the Recalibration Involved in Visuomotor Adaptation.- 5.6. Conditions for Visuomotor Adaptation.- 6. References.- 10 Effects of Selective Adaptation on the Perception of Speech and Visual Patterns: Evidence for Feature Detectors.- 1. Introduction.- 2. Selective Adaptation and the Perception of Speech.- 2.1. Analysis of Voicing and Place of Articulation.- 2.2. Manner of Articulation.- 2.3. Contingent Adaptation Effects.- 2.4. Auditory vs. Phonetic Loci of the Adaptation Effects.- 2.5. Response Bias vs. Sensory Explanations.- 2.6. Nature of Feature Detectors for Speech.- 2.7. Operating Characteristics of Feature Detectors for Speech.- 2.8. Summary.- 3. Selective Adaptation and Visual Perception.- 3.1. Orientation.- 3.2. Spatial Frequency.- 3.3. Motion.- 3.4. Orientation and Color.- 3.5. Spatial Frequency and Color.- 3.6. Motion and Color.- 3.7. Monocularity of Color-Selective Units.- 3.8. Nature and Operation of Detectors for Visual Information.- 4. Final Comments.- 5. References.- 11 Development of Form Perception in Repeated Brief Exposures to Visual Stimuli.- 1. Introduction.- 2. Theoretical Background.- 2.1. Microgenetic Theory.- 2.2. Clarity Hypothesis and Hebbian Cell Assemblies.- 2.3. Decision-Making Models.- 2.4. Other Accounts of the Repetition Effect.- 3. Summary and Conclusions.- 4. References.- 12 Stimuli, the Perceiver, and Perception.- 1. Introduction.- 2. A Case of Serendipity.- 3. The Principle of Color Conversion.- 4. On the General Nature of Adaptation-Level Theory.- 5. Anchor Effects, Contrast, and Assimilation.- 6. Constancy, Transposition, and Stimulus Generalization.- 7. Illusions.- 8. Vigilance.- 9. Adaptation-Level Shifts: Changes in Judgment or Perception?...- 10. Conditions for Pooling.- 11. Adaptation-Level Theory and Psychophysics.- 12. Conclusion.- 13. References.- 13 A Perceptual View of Conceptual Development.- 1. Introduction.- 2. Subproblem Analysis of Discrimination Learning.- 3. Performance on Successively Learned Instances of a Concept.- 4. Studies of Perceptual Pretraining.- 5. Memory for Instances and Categories.- 6. Overview.- 7. Theoretical Treatment.- 7.1. Proposition: A Perceptual Basis of Conceptual Development.- 7.2. Is the Facilitative Pretraining Perceptual in Nature?.- 7.3. Are the Age Differences in Object vs. Dimensional Control a Matter of Ability or of Performance?.- 7.4. Is Dimensional Learning a Function of Maturation or of Experience?.- 7.5. Relation of Present Theory to Others.- 8. References.- Author Index.

Abstract: Production of the signals of any language must to some extent depend on the modality of that production. The vocal apparatus can produce only a limited range of all the sounds that a human ear can detect, and there is certainly a limit to the possible duration and sequencing of these sounds. Similarly, the production of language signals must be related to the perceptual system receiving them. A difference between two sounds must be a difference that the hearer can immediately, accurately, and automatically detect before that difference can be used to convey a distinction between two elements of a language. The production of language signals, therefore, must be constrained by the apparatus used to receive them. We would expect that sign languages of the deaf would evolve in such a way that their units would become less perceptually ambiguous. Since sign languages are received and initially processed by the visual system, we would expect that the rules for the formation of signs of a sign language would be constrained by the limits of the visual system. One of the important limits of human vision is that it is not equally acute in all parts of the field it takes in. When we focus on a point, we can see a great deal of detail in the area immediately surrounding that point, because the image of the point and area falls on the most

Abstract: The oculomotor performance of 25 dyslexic and 1 9 normal children was evaluated to determine whether or not dyslexia involves deficits in oculomotor function or visual perception. When the children were required to follow a meaningless target or to solve pictorial tasks, the two age-matched

Abstract: Publisher Summary Occasionally, the eyes may appear to move together, smoothly and slowly; however, only when the observer follows the movement of some object in his field of view. It seems easy to follow quite closely what the observer is doing. Eye movements very conveniently betray a great deal about the distribution of a person's visual attention and, indirectly, about his deeper mental processes also. Growing realization of this fact, together with continuing refinement of techniques for monitoring eye position, largely explain the recent increase in interest in eye movements. Eye movements are no longer mainly studied in their own right in specialized laboratories; eye-movement measurement is becoming a routine and valuable contributor to the studies of many perceptual and cognitive problems. This chapter discusses the role of eye movements in perception rather than the study of eye movements themselves. It discusses the benefits and possible costs of having a perceptual system that is very reliant on eye movements; benefits in the sense that eye movements ensure the maintenance of vision and allow the effective deployment of the high-acuity foveal channel; costs in the sense that perception of a stable world is required despite the gross changes in retinal images produced by large and frequent eye movements.

Abstract: A man with a tumor in the right superior parietal lobule had difficulty reaching for visualized objects. There were no significant deficits in visual sensation, visual attention, somatosensory function, elementary motility, praxis, or visuospatial performance. If allowed to visually fixate the target before reaching, he misreached only with his left arm and only when he was not allowed to observe the reaching limb. If he was required to maintain central visual fixation while reaching into his peripheral visual fields, his left arm misreached into both visual hemifields but his right arm misreached only into the left visual hemifield. These results demonstrate abnormalities, referable to both the contralateral arm and the contralateral visual field, that can neither be reduced to elementary disturbances of visual or somatosensory function nor to an elementary disturbance of motility. This pattern of misreaching has not been previously reported in human subjects or in experimental animals, but this may be attributable to differences of methodology. The misreaching observed in this patient may correspond to loss of posterior parietal neurons serving a supramodal integrative function.

Abstract: A method was developed to investigate transfer properties of neurons in the visual system using pictures of complex visual stimuli. The picture is moved over the receptive field of a neuron so that it can scan it along programmed lines. The activity of the neuron during the scanning procedure is presented in a two-dimensional dot display on scale with the original picture. By superposition of the stimulus and the transfer pattern, one can find out to which detail of a stimulus the neuron responds. Neurons in the first intracerebral relay of the visual system, the lateral geniculate body, reduce a complex stimulus, such as a photograph of a natural environment, to its contours. Cortical cells only respond to contours either of a limited or of a wider range of orientations (simple and complex cells, respectively). But the course of contours is only described by a continuous representation of these contours in the cortical map of the visual field. This is done by the simple cells, which have small receptive fields and thus a higher resolving power, whereas complex cells with their large receptive fields monitor the approximate location of a moving stimulus. The function of these two classes of neurons is discussed in terms of visual behavior, i.e., for fixation, hold, and binocular vergence movements (simple cells), and for detection of moving objects and motor command signals towards these objects (complex cells). These functions are an important condition for foveal vision which is the basis of perception in primates. An important function of orientation sensitivity of simple cells may be the binocular alignment of contours in binocular fusion and stereoscopic vision.

Abstract: The impulse discharges of neurons in the inferior parietal association cortex (area 7) were studied in the alert, behaving rhesus monkey, trained to fixate and follow visual targets. Four classes of cells related to visual or visuomotor function were found. Cells of one of these are sensitive to visual stimuli and have large, contralateral receptive fields with maximal sensitivity in the far temporal quadrants. Cells of the other three classes are related to visuomotor functions: visual fixation, tracking, and saccades. They are neither sensory nor motor in the usual sense for they are activated only by interested fixation of gaze or tracking, or before visually evoked saccadic eye movements. They are not activated during the spontaneous saccades and fixations that the monkey makes while casually exploring his environment. It is hypothesized that the light-sensitive neurons provide the visual input to the visuomotor cells that, in turn, produce a command signal for the direction of visual attention and for shifting the focus of attention from one target to another.

Abstract: Three experiments assessed the effect of visual familiarity of words on same-different reaction times (RTs) in a simultaneous-matching task. Visual familiarity was disrupted by using upper- and lowercase letters within sequences. The results for same judgments in Experiments 1 and 2 indicated that visual familiarity was responsible for most of the large word-superiority effect obtained. The third experiment investigated the extent to which the effects obtained with word-frequency and orthographic-regularity manipulations were due to visual familiarity. For same RTs the results indicated both types of familiarity effects were dependent on visual familiarity. With pure-case stimuli, high-frequency words were processed faster than low-frequency words. Low-frequency words and orthographically regular nonwords produced similar reaction times, and both were processed faster than unpronounceable nonwords. These effects were not evident with mixed-case stimuli. All three studies showed visual familiarity to be responsible for differences in slope over sequence length between words and nonwords. Results with different judgments were dissimilar enough from the pattern of results for same judgments to present problems of interpretation, and it was suggested that additional or alternative processes were involved. The implications of these data for models of word processing were discussed. Language: en

Abstract: Field dependence as a perceptual style refers to the extent to which a person is capable of overcoming an embedding context in order to perceive relevant targets. This paper reports on two studies that examined the relationship between field dependence and on-the-road visual search behavior. In the first study, concerned with eye movements in curve negotiation, it was found that field-dependent subjects have a less effective visual search pattern. In the second study, young and aged drivers were compared on several information processing tasks and on their ability to maintain their eyes closed part of the time while driving. Of the various information processing tasks, only field dependence and visual search time correlated significantly with the mean time the drivers needed to maintain their eyes open while driving. Together the two studies indicate that field dependent subjects require more time to proces the available visual information and are less effective in their visual search pattern.

Abstract: When one is concerned with the investigation of spatial frequency channels in the visual system, one often has to face the use of periodical visual stimuli which are generated on television displays by means of the sophisticated techniques of modern electronics. However, many physiologists and psychologists have criticized periodical stimuli as being visually unnatural and maintain that our visual world is composed of more complicated stimuli such as bars and edges at various orientations. Admittedly, the experimental visual world utilized by visual scientists is very limited and most of the time it is seemingly irrelevant and uninteresting to the subjects of the experiment. Without a doubt, the familiarity of objects and the emotions evoked in recognizing them are essential factors underlying pattern perception. Numerous experiments, both old and new, indicate that the capabilities of our visual systems are molded, at least in part, by our previous experience of the external world.