scholarly journals Useful visual field size for pattern perception

1979 ◽  
Vol 25 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Shinya Saida ◽  
Mitsuo Ikeda
Keyword(s):  
Visual Field ◽  
Pattern Perception ◽  
Field Size

Visual Field Size Criteria for Mobility Rehabilitation Referral

2010 ◽  
Vol 87 (12) ◽  
pp. E948-E957 ◽  
Author(s):  
Jan E. Lovie-Kitchin ◽  
Grace P. Soong ◽  
Shirin E. Hassan ◽  
Russell L. Woods
Keyword(s):  
Visual Field ◽  
Field Size

scholarly journals Visual performance in behaving cats after prenatal unilateral enucleation

1993 ◽  
Vol 90 (23) ◽  
pp. 11142-11146 ◽  
Author(s):  
S Bisti ◽  
C Trimarchi
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Receptive Field ◽  
Receptive Fields ◽  
Direction Selectivity ◽  
Visual Performance ◽  
Field Size ◽  
Electrophysiological Recordings ◽  
Severe Impairment ◽  
Orientation Columns

Prenatal unilateral enucleation in mammals causes an extensive anatomical reorganization of visual pathways. The remaining eye innervates the entire extent of visual subcortical and cortical areas. Electrophysiological recordings have shown that the retino-geniculate connections are retinotopically organized and geniculate neurones have normal receptive field properties. In area 17 all neurons respond to stimulation of the remaining eye and retinotopy, orientation columns, and direction selectivity are maintained. The only detectable change is a reduction in receptive field size. Are these changes reflected in the visual behavior? We studied visual performance in cats unilaterally enucleated 3 weeks before birth (gestational age at enucleation, 39-42 days). We tested behaviorally the development of visual acuity and, in the adult, the extension of the visual field and the contrast sensitivity. We found no difference between prenatal monocularly enucleated cats and controls in their ability to orient to targets in different positions of the visual field or in their visual acuity (at any age). The major difference between enucleated and control animals was in contrast sensitivity:prenatal enucleated cats present a loss in sensitivity for gratings of low spatial frequency (below 0.5 cycle per degree) as well as a slight increase in sensitivity at middle frequencies. We conclude that prenatal unilateral enucleation causes a selective change in the spatial performance of the remaining eye. We suggest that this change is the result of a reduction in the number of neurones with large receptive fields, possibly due to a severe impairment of the Y system.

Recent Advances in Understanding Peripheral Vision

1986 ◽  
Vol 30 (6) ◽  
pp. 601-603 ◽  
Author(s):  
Mark W. Cannon
Keyword(s):  
Visual Field ◽  
Spatial Pattern ◽  
Peripheral Vision ◽  
Pattern Perception ◽  
Recent Advances ◽  
Entire Visual Field

Recent experiments have revealed a considerable uniformity in the mechanisms mediating spatial pattern perception over the entire visual field.

Effect of Peripheral Visual Field Size upon Visual Search in Children and Adults

Perception ◽  
1980 ◽  
Vol 9 (4) ◽  
pp. 451-455 ◽  
Author(s):  
Naoyuki Osaka
Keyword(s):  
Visual Search ◽  
Visual Field ◽  
Power Function ◽  
Age Groups ◽  
Field Size ◽  
Peripheral Visual Field ◽  
Cube Root ◽  
Age Related

Twenty observers in each of the age groups, three, four, five, and twenty-one years, were asked to identify pictures displayed through five different sizes of peephole. Recognition latency changed as a cube-root power function of aperture area. It was found that latency decreased as age and area increased. However, the exponent of the power function showed little age-related change. Effectiveness of the peripheral visual field size was discussed in terms of magnitude of the exponent.

Response properties of neurons in temporal cortical visual areas of infant monkeys

1993 ◽  
Vol 70 (3) ◽  
pp. 1115-1136 ◽  
Author(s):  
H. R. Rodman ◽  
S. P. Scalaidhe ◽  
C. G. Gross
Keyword(s):  
Nitrous Oxide ◽  
Temporal Cortex ◽  
Receptive Fields ◽  
Stimulus Presentation ◽  
Pattern Perception ◽  
Inferior Temporal Cortex ◽  
Field Size ◽  
Visual Response ◽  
Control Adult ◽  
Oxide Anesthesia

1. Inferior temporal cortex (IT) is a "high-order" region of primate temporal visual cortex implicated in visual pattern perception and recognition. To gain some insight into the development of this area, we compared the properties of single neurons in IT in infant monkeys ranging from 5 wk to 7 mo of age with those of neurons in IT in adult animals. Both anesthetized and awake behaving paradigms were used. 2. In immobilized infant monkeys under nitrous oxide anesthesia, the incidence of visually responsive cells was markedly less than in adult monkeys studied under similar conditions. In infants 4-7 mo of age, only half of IT neurons studied were visually responsive, compared with > 80% in adult monkeys. In monkeys < 4 mo old, even fewer (< 10%) could be visually driven. "Habituation" of IT cells to repeated stimulus presentation appeared more pronounced in infant monkeys under nitrous oxide anesthesia than in adult animals. 3. IT cells in the anesthetized infant monkeys that did respond showed receptive field properties similar to those of responsive adult IT neurons studied under similar conditions. Two thirds of the receptive fields plotted in the anesthetized 4 to 7-mo-old group were bilateral, and median field size did not differ between the infants and comparable adult groups, being approximately 20 degrees on a side in each case. 4. In contrast to the results obtained under anesthesia, most IT cells in alert infant monkeys 5 wk-7 mo of age (80%) were responsive to visual stimuli, and this incidence of visually responsive IT neurons did not differ from that obtained in awake adult macaques. However, response magnitude, measured as spikes per second above baseline rate, was significantly lower in the infant alert sample than in the adult control (5.2 vs. 12.6 spikes/s, mean +/- SE, deviation from spontaneous rate, respectively). 5. In addition to having lower magnitudes of visual response, IT cells in the awake infants also tended to have longer and more variable latencies. The overall mean for the infant cells was 196 ms, compared with an overall mean of 140 ms for IT neurons in the alert control adult. 6. Although the magnitude of response of neurons in alert infant IT cortex was lower overall, the incidence and features of stimulus selectivity shown by alert infant IT neurons were strikingly similar to those of IT cells of both anesthetized and unanesthetized adult monkeys.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of Stimulus and Field Size on the Accuracy of Orientation in the Homogeneous Environment

1965 ◽  
Vol 20 (1) ◽  
pp. 167-172
Author(s):  
Milton S. Katz ◽  
William Metlay ◽  
Paul A. Cirincione
Keyword(s):  
Visual Field ◽  
Small Error ◽  
Field Size ◽  
Homogeneous Field ◽  
Small Target ◽  
Systematic Fashion ◽  
Left And Right ◽  
Initial Starting ◽  
Initial Target ◽  
Homogeneous Environment

The effects of various size targets and the extent of the visual field on the accuracy of orientation in the homogeneous environment were investigated by requiring Ss to recenter four different targets, starting from 11 locations, in a 270° homogeneous field. The results showed that: (1) each S positioned all four targets in a preferred field, (2) small error scores and consistency in positioning around perceived centers were found with only three of the four targets, (3) in all cases the largest error and greatest variability was in centering the smallest target, (4) absolute errors were not related in any systematic fashion to the initial starting points, and (5) with respect to initial target presentations, i.e., left and right fields, S's errors tended to be smaller in the field containing that S's perceived center. It was suggested that the variability of the small target could be accounted for, in part, by the autokinetic effect.

Size of the Visual Field in Collegiate Fast-Pitch Softball Players and Nonathletes

1995 ◽  
Vol 81 (3_suppl) ◽  
pp. 1307-1312 ◽  
Author(s):  
William P. Berg ◽  
Suzanne M. Killian
Keyword(s):  
Visual Field ◽  
Undergraduate Students ◽  
Division I ◽  
Field Size ◽  
Female College Students ◽  
Kinetic Perimetry ◽  
Skill Test ◽  
Batting Performance ◽  
The Mean ◽  
The Relationship

The purpose of this study was to examine whether visual-field size differed between female Division I collegiate fast-pitch Softball players and female college students who were nonathletes. The relationship between visual-field size and batting performance among the softball players was also examined. 24 female undergraduate students (12 varsity fast-pitch softball players and 12 nonathletes) participated. The size of the visual field was measured via manual kinetic perimetry, and batting performance was assessed using a batting-skill test as well as batting averages for an entire competitive season. Analyses indicated that the mean visual-field size of softball players was significantly larger than that of nonathletes. However, there was no relationship between visual-field size and batting performance among the softball players. Results are discussed with respect to the origin of the superiority of visual-field size of softball players.

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