Showing papers on "Visual perception published in 1968"

Two mechanisms of vision in primates.

Abstract: Experiments with split-brain monkeys led me to consider that vision of space and vision of object identity may be subserved by anatomically distinct brain mechanisms. In this paper I examine the visual mechanisms of the brain to test the idea that vision involves two parallel processes; one ambient, determining space at large around the body, the other focal which examines detail in small areas of space.

Choice reaction time: An analysis of the major theoretical positions.

Abstract: Choice reaction time to visual stimuli - analysis of major theoretical positions to perceptual recognition theories

Confusions Among Visually Perceived Consonants

Abstract: Eighteen college students with normal hearing responded to the visual perception of initial and final consonants in an English-like phonetic environment in a test of the homopheny of consonant soun...

What gives rise to the perception of motion

Abstract: The assumption that displacement of the retinal image over the retina is the basis for all perception of motion is rejected. The reasons for the plausibility of this assumption are considered. It is part of the traditional theory that retinal sensations are entailed in visual perception. But it involves a misconception of how the eyes work. Another theory of the information for perceiving motion is proposed in terms of the ambient array of light. The registering of subjective bodily movements by vision is contrasted with the detecting of objective environmental motions. A number of century-old puzzles are resolved by this approach and a set of novel experiments is suggested. Experimental studies of the perception of motion in the past, especially of visual motion, have failed to resolve the old puzzles or to yield any kind of general explanation. The root of the trouble may be a persistent misconception of what gives rise to the perception—an erroneous but plausible assumption about the stimulus. What is the effective stimulus that always elicits a sensation or perception of motion? The physical motion of an object in the world, one might answer, but this is obviously not sufficient unless the object is illuminated or luminous, and unless it lies within the field of view of the observer. The motion must be specified somehow in the light to an organism and it must also enter an eye. When it is specified in the light and does enter the eye the animal almost always detects it, as the 1 This summary is based on a series of investigations over the last 10 years on the perception of motion and space carried out with the support of the Office of Naval Research under Contract NONR 401(14) with Cornell University. A bibliography of the published studies may be obtained from the author. This is the third summary of the project to be published in Psychological Review (Gibson, 1954, 1957). It is hoped that each summary makes some theoretical advance over the previous one. study of behavior shows. This is what is meant by saying that animals are very sensitive to "motion." But physical motion is not the same as optical motion.

Movements of the eye.

Abstract: A SPECIAL CAMERA HAS BEEN DEVISED WHICH RECORDS THE MOVEMENTS OF THE EYE IN THE COURSE OF SUCH ACTIVITIES AS LOOKING AT PICTURES OR DRIVING AN AUTOMOBILE. IT REVEALS THAT THE EYE MOVES IN A SERIES OF RAPID JUMPS (SACCADES) WHICH SEEM TO BE CONTROLLED BY THE BRAIN AS THOUGH THERE WERE COORDINATES BETWEEN ONE FIXATION AND THE NEXT. IN READING, THE EYE JUMPS FROM ONE GROUP OF WORDS TO ANOTHER, FIXATING ONLY A FEW. IN DRIVING THE EYE IS CONSTANTLY MOVING. WHAT IS SEEN DOES NOT NECESSARILY REGISTER IN THE BRAIN UNLESS IT IS OF IMPORTANCE. THE LINK BETWEEN THE IMAGE AND THE MIND IS CONTROLLED BY THE BRAIN WHICH ACTS AS A FILTER, CHOOSING WHAT IT WILL OR WILL NOT 'SEE.' DRIVERS USE BOTH DIRECT VISION (FOCUSING ON IMPORTANT OBJECTS) AND PERIPHERAL VISION (IMPRESSIONS OF MOTION OR LIGHT ON THE EDGE OF THE FIELD OF VISION). FROM A STUDY OF NORMAL EYE MOVEMENTS, IT IS POSSIBLE TO DESIGN CONTROL PANELS FOR CARS OR AIRPLANES WHICH GROUP THE NECESSARY INFORMATION IN EASILY VISIBLE AREAS.

Sensory traces versus the psychological moment in the temporal organization of form.

Abstract: Visual stimuli were constructed so that any given stimulus by itself appeared to be a random collection of dots. However, when 2 corresponding stimuli were superimposed by means of a 2-field tachistoscope, a 3-letter nonsense syllable was perceived. When a temporal interval was introduced between the presentation of the corresponding stimulus halves, organization in perception was found to be a decreasing function of interstimulus interval over a range in excess of 100 msec. The applicability of a concept of a decaying sensory trace in accounting for the integration of form perception over time was investigated. Clear evidence of a decaying sensory trace was found; however, this concept was unable to account for all aspects of the data. The applicability of a psychological moment acting in conjunction with a decaying sensory trace was considered as was also the possibility of discontinuity detectors which inhibit or break up temporal organization.

Parallel and divergent patterns in blind and sighted infants.

Abstract: (1968). Parallel and Divergent Patterns in Blind and Sighted Infants. The Psychoanalytic Study of the Child: Vol. 23, No. 1, pp. 264-300.

Retention of visual and verbal codes of the same stimuli

Abstract: 80 6"s were shown drawings of common objects and later given verbal recall tests for the object names, followed by visual recognition tests scaled to reflect the accuracy of the visual retention. A 2X2X2 design permitted assessment of the effects of degree of training, of retention interval, and of instructions to verbalize during training. The most significant finding was that the probability of recall of object names is essentially uncorrelated with the accuracy of visual recognition of these same objects by the same 5s. As an explanation the possibility of independent storage systems for the visual and verbal information related to the same objects was considered but rejected as improbable. Verbal recall 2 wk. after training seemed to be based largely upon the retrieval of visual storage. The receding potential of visual storage into a verbal concept appears to be determined by those aspects of the visual storage which distinguish the object class, and not by aspects which distinguish among objects of the same class. Visual storage losses of both aspects occurred during the 2-wk. period examined, but no significant correlation existed between the 2 types of losses. Nonverbal information may be encoded verbally to facilitate storage and retrieval. Some verbal receding seems to occur almost instantaneously at the time of the input; in other instances the information may be stored nonverbally, and the receding is delayed until retrieval becomes necessary. Receding would appear to be

Visual evoked response correlates of unconscious mental processes.

Abstract: Average evoked responses and accompanying free associations elicited by subthreshold visual stimuli were studied to determine if a differential discrimination between two stimuli would be reflected in either or both of these responses. The results indicate that the effects of subliminal perception are encoded in the average evoked response and also influence the content of free associations.

Voluntary attention in peripheral vision and its effects on acuity and differential thresholds

Abstract: The three experiments described in this paper were intended to show whether voluntary attention to a particular part of the peripheral visual field had any effect on the accuracy of the subject's p...

Sensory modality and object-naming in aphasia.

Abstract: Twenty-seven aphasics, 12 right-brain-injured, and 12 normal subjects were presented with 16 objects for tactile naming, 16 for auditory naming, and 16 for olfactory naming. All 48 objects were als...

Visual sameness: a choice time analysis of pattern recognition processes.

Abstract: Ss judged the \"sameness\" of pairs of matrixes, each having several cells blackened at random. One group (Similarity search) classified matrix pairs as \"same\" if they had even one pair of blackened cells in corresponding locations. A second group (Identity search) classified pairs as \"same\" that were identical with respect to all blackened cell locations. Decision times of the Similarity-search group were much longer than those of the Identity-search group. While the performance of the Similarity-search Ss indicated they were engaged in a serial processing of the stimulus array that of the Identity-search Ss in some conditions closely approximated gestalt processing.

Visual Perception and Map Design

Abstract: Visual perception is reviewed in relation to the search for principles in map design. Various cues of 'depth' are examined as aids in the specification of the qualities and dimensions of map symbols. Maps are analysed on the basis of 'receding planes', each plane containing a specific selection of graphic information. A design procedure is outlined in this content, and finally an example of a thematic map, the Residential Land Use of Glasgow-1965, is presented in detail.

Comparison of sensitivity for the perception of bodily rotation and the oculogyral illusion

Abstract: Human angular acceleration sensitivity compared using perception of bodily rotation and oculogyral illusion as indicators, discussing nature of illusion

Visual suppression during passive eye movement.

Abstract: Visual suppression during passive eye movement compared to active eye movement to determine origin as retinal or central