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Author (down) Wolfe, J.M. openurl 
  Title Hidden visual processes Type Journal Article
  Year 1983 Publication Scientific American Abbreviated Journal Sci Am  
  Volume 248 Issue 2 Pages 94-103  
  Keywords Color Perception/*physiology; Humans; Motion Perception/physiology; Ocular Physiology; Vision; Visual Perception/*physiology  
  Abstract Isoluminant stimulus is an image whose edges are defined only by a change in color, not by change in brightness. The stimulus here is imperfect: the blue parts and the green parts of the image are only as nearly equal in brightness as they can be on the printed page. Moreover, the change in brightness beyond the edge of the page is apparent, and so is the fact that the reader is holding the magazine at reading distance. When such cues are removed under laboratory conditions, subjects faced with an isoluminant stimulus prove unable to bring its edges into focus. This deficiency contributes to making a familiar face hard to recognize. The experiment indicates that the brain process underlying visual accommodation (the focusing of the eyes) cannot “see” color; it is a hidden process distinct from the processes that lead to perception. The image shows Groucho Marx as he appeared in the motion picture Horse Feathers.  
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  ISSN 0036-8733 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:6836258 Approved no  
  Call Number Equine Behaviour @ team @ Serial 4066  
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Author (down) van Niekerk, H.P. openurl 
  Title Ethological studies within the man-horse relationship Type Journal Article
  Year 1980 Publication Journal of the South African Veterinary Association Abbreviated Journal J S Afr Vet Assoc  
  Volume 51 Issue 4 Pages 237-238  
  Keywords Animals; Behavior, Animal; Hearing; Horses/*physiology; Humans; Smell; Taste; Touch; Vision  
  Abstract Certain aspects of ethology and the horse's senses are discussed to bring about a better understanding between man and horse. Furthermore the behaviour of horses with respect to housing, feeding, breeding, veterinary treatment and work are considered.  
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  Series Volume Series Issue Edition  
  ISSN 1019-9128 ISBN Medium  
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  Notes PMID:7241494 Approved no  
  Call Number refbase @ user @ Serial 1960  
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Author (down) Tomkins, L.M.; Williams, K.A.; Thomson, P.C.; McGreevy, P.D. url  doi
openurl 
  Title Sensory Jump Test as a measure of sensory (visual) lateralization in dogs (Canis familiaris) Type Journal Article
  Year 2010 Publication Journal of Veterinary Behavior Abbreviated Journal  
  Volume 5 Issue 5 Pages 256-267  
  Keywords sensory lateralization; monocular vision; binocular vision; jump kinematics; dog  
  Abstract Sensory lateralization in dogs (n = 74) was investigated in this study using our innovation, the Sensory Jump Test. This required the modification of head halters to create three different ocular treatments (binocular, right, and left monocular vision) for eye preference assessment in a jumping task. Ten jumps were recorded as a jump set for each treatment. Measurements recorded included (i) launch and landing paws, (ii) type of jump, (iii) approach distance, (iv) clearance height of the forepaw, hindpaw, and the lowest part of the body to clear the jump, and (v) whether the jump was successful. Factors significantly associated with these jump outcomes included ocular treatment, jump set number, and replication number. Most notably, in the first jump set, findings indicated a left hemispheric dominance for the initial navigation of the Sensory Jump Test, as left monocular vision (LMV) compromised of jumping more than right monocular (RMV) and binocular vision, with a significantly reduced approach distance and forepaw clearance observed in dogs with LMV. However, by the third jump set, dogs undergoing LMV launched from a greater approach distance and with a higher clearance height, corresponding to an increase in success rate of the jump, in comparison with RMV and binocular vision dogs. A marginally non-significant RMV bias was observed for eye preference based on the laterality indices for approach distance (P = 0.060) and lowest body part clearance height (P = 0.067). A comparison between eye preference and launching or landing paws showed no association between these measures of sensory and motor laterality. To our knowledge, this is the first study to report on sensory lateralization in the dog, and furthermore, to compare both motor and sensory laterality in dogs.  
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  ISSN 1558-7878 ISBN Medium  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ S1558-7878(10)00019-5 Serial 5379  
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Author (down) Timney, B.; Keil, K. doi  openurl
  Title Local and global stereopsis in the horse Type Journal Article
  Year 1999 Publication Vision Research Abbreviated Journal Vision Res  
  Volume 39 Issue 10 Pages 1861-1867  
  Keywords Animals; Depth Perception/*physiology; Female; Horses/*physiology; Pattern Recognition, Visual/physiology; Psychophysics; Sensory Thresholds/physiology; Vision, Binocular/physiology; Vision, Monocular/physiology  
  Abstract Although horses have laterally-placed eyes, there is substantial binocular overlap, allowing for the possibility that these animals have stereopsis. In the first experiment of the present study we measured local stereopsis by obtaining monocular and binocular depth thresholds for renal depth stimuli. On all measures, the horses' binocular performance was superior to their monocular. When depth thresholds were obtained, binocular thresholds were several times superior to those obtained monocularly, suggesting that the animals could use stereoscopic information when it was available. The binocular thresholds averaged about 15 min arc. In the second experiment we obtained evidence for the presence of global stereopsis by testing the animals' ability to discriminate between random-dot stereograms with and without consistent disparity information. When presented with such stimuli they showed a strong preference for the cyclopean equivalent of the positive stimulus with the real depth. These results provide the first behavioral demonstration of a full range of stereoscopic skills in a lateral-eyed mammal.  
  Address Department of Psychology, Faculty of Social Science, University of Western Ontario, London, Canada. timney@julian.uwo.ca  
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  Series Volume Series Issue Edition  
  ISSN 0042-6989 ISBN Medium  
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  Notes PMID:10343877 Approved yes  
  Call Number Equine Behaviour @ team @ Serial 3580  
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Author (down) Smith, S.; Goldman, L. url  openurl
  Title Color discrimination in horses Type Journal Article
  Year 1999 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 62 Issue 1 Pages 13-25  
  Keywords Horses; Vision; Color; Discrimination; Behavior  
  Abstract Four Arabian horses and one Thoroughbred were presented with a series of two-choice color vs. gray discrimination problems. Testing was done in a stall containing a wall with two translucent panels that were illuminated from behind by light projected through color or gray filters to provide the discriminative stimuli. Horses first learned to push one of the panels in order to receive the food reward behind the positive stimulus in an achromatic light-dark discrimination task, and were then tested on their ability to discriminate between gray and four individual colors: red (617 nm), yellow (581 nm), green (538 nm), and blue (470 nm). The criterion for learning was set at 85% correct responses, and final testing for all color vs. gray discriminations involved grays of varying intensities, making brightness an irrelevant cue. Three subjects were tested with all four colors. Two of those subjects successfully reached the criterion for learning on all four color vs. gray discriminations, while the third reached criterion with red and blue, but performed at chance levels for yellow and green. A fourth horse was only tested with green and yellow, and a fifth only with blue, and both of those horses successfully reached criterion on the discriminations they attempted. With the exception of the one subject's poor performance with yellow and green, there was no significant difference between horses on any of the discrimination tasks, and no significant difference in their performance with different colors. The results suggest that horses have color vision that is at least dichromatic, although partial color-blindness may occur in some individuals.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 850  
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Author (down) Siniscalchi, M.; Sasso, R.; Pepe, A.M.; Vallortigara, G.; Quaranta, A. url  doi
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  Title Dogs turn left to emotional stimuli Type Journal Article
  Year 2010 Publication Behavioural Brain Research Abbreviated Journal Behav. Brain. Res.  
  Volume 208 Issue 2 Pages 516-521  
  Keywords Dog; Laterality; Vision; Behaviour; Physiology; Cognition; Emotion; Animal welfare  
  Abstract During feeding behaviour, dogs were suddenly presented with 2D stimuli depicting the silhouette of a dog, a cat or a snake simultaneously into the left and right visual hemifields. A bias to turn the head towards the left rather than the right side was observed with the cat and snake stimulus but not with the dog stimulus. Latencies to react following stimulus presentation were lower for left than for right head turning, whereas times needed to resume feeding behaviour were higher after left rather than after right head turning. When stimuli were presented only to the left or right visual hemifields, dogs proved to be more responsive to left side presentation, irrespective of the type of stimulus. However, cat and snake stimuli produced shorter latencies to react and longer times to resume feeding following left rather than right monocular visual hemifield presentation. Results demonstrate striking lateralization in dogs, with the right side of the brain more responsive to threatening and alarming stimuli. Possible implications for animal welfare are discussed.  
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  ISSN 0166-4328 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 5080  
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Author (down) Saslow, C.A. url  doi
openurl 
  Title Understanding the perceptual world of horses Type Journal Article
  Year 2002 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 78 Issue 2-4 Pages 209-224  
  Keywords Horse; Perception; Vision; Olfaction; Touch; Hearing; Pain; Training; Psychophysics; Umwelt  
  Abstract From the viewpoint of experimental psychology, there are two problems with our current knowledge of equine perception. The first is that the behavioral and neurophysiological research in this area has enormous gaps, reflecting that this animal is not a convenient laboratory subject. The second is that the horse, having been a close companion to humans for many millennia, entrenched anecdotal wisdom is often hard to separate from scientific fact. Therefore, any summary at present of equine perception has to be provisional. The horse appears to have developed a visual system particularly sensitive to dim light and movement, it may or may not have a weak form of color vision in part of the retina, it has little binocular overlap, and its best acuity is limited to a restricted horizontal band which is aimed primarily by head/neck movements. However, the total field of view is very large. Overall, as would be expected for a prey animal, horse vision appears to have evolved more for detection of predator approach from any angle than for accurate visual identification of stationary objects, especially those seen at a distance. It is likely that, as for most mammals except the primates, horses rely more heavily on their other senses for forming a view of their world. Equine high-frequency hearing extends far above that of humans, but horses may be less able to localize the point of origin of brief sounds. The horse's capacity for chemoreception and its reliance on chemical information for identification may more closely resemble that of the dog than of the human. Its tactile sensitivity is high, and the ability of its brain and body to regulate pain perception appears to be similar to that found in other mammals. There is room for a great deal of future research in both the area of equine perception and sensory-based cognition, but for the present time persons interacting with this animal should be made aware of the importance of the sounds they make, the movements of their bodies, the way they touch the animal, and the odors they emit or carry on their clothing.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 400  
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Author (down) Regolin, L.; Marconato, F.; Vallortigara, G. doi  openurl
  Title Hemispheric differences in the recognition of partly occluded objects by newly hatched domestic chicks (Gallus gallus) Type Journal Article
  Year 2004 Publication Animal Cognition Abbreviated Journal Anim. Cogn.  
  Volume 7 Issue 3 Pages 162-170  
  Keywords Animals; Discrimination Learning/physiology; Dominance, Cerebral/*physiology; Female; Form Perception/*physiology; Imprinting (Psychology)/*physiology; Pattern Recognition, Visual/*physiology; Photic Stimulation; Random Allocation; Vision, Monocular/*physiology  
  Abstract Domestic chicks are capable of perceiving as a whole objects partly concealed by occluders (“amodal completion”). In previous studies chicks were imprinted on a certain configuration and at test they were required to choose between two alternative versions of it. Using the same paradigm we now investigated the presence of hemispheric differences in amodal completion by testing newborn chicks with one eye temporarily patched. Separate groups of newly hatched chicks were imprinted binocularly: (1) on a square partly occluded by a superimposed bar, (2) on a whole or (3) on an amputated version of the square. At test, in monocular conditions, each chick was presented with a free choice between a complete and an amputated square. In the crucial condition 1, chicks tested with only their left eye in use chose the complete square (like binocular chicks would do); right-eyed chicks, in contrast, tended to choose the amputated square. Similar results were obtained in another group of chicks imprinted binocularly onto a cross (either occluded or amputated in its central part) and required to choose between a complete or an amputated cross. Left-eyed and binocular chicks chose the complete cross, whereas right-eyed chicks did not choose the amputated cross significantly more often. These findings suggest that neural structures fed by the left eye (mainly located in the right hemisphere) are, in the chick, more inclined to a “global” analysis of visual scenes, whereas those fed by the right eye seem to be more inclined to a “featural” analysis of visual scenes.  
  Address Department of General Psychology, University of Padova, Via Venezia 8, 35131, Padova, Italy. lucia.regolin@unipd.it  
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  ISSN 1435-9448 ISBN Medium  
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  Notes PMID:15241654 Approved no  
  Call Number Equine Behaviour @ team @ Serial 2519  
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Author (down) Mills, D.S.; Riezebos, M. doi  openurl
  Title The role of the image of a conspecific in the regulation of stereotypic head movements in the horse Type Journal Article
  Year 2005 Publication Applied Animal Behaviour Science Abbreviated Journal Appl. Anim. Behav. Sci.  
  Volume 91 Issue 1-2 Pages 155-165  
  Keywords Behaviour; Horse; Nodding; Perception; Stereotypy; Vision; Weaving  
  Abstract Weaving is a common locomotor stereotypy in horses, which has been shown to be reduced by the presence of a mirror in the stable; however, it remains unclear whether this effect is due to the reflected image of a horse or some other property associated with the introduction of a mirror. To investigate this further, the response of six known weaving horses to each of three different types of poster was recorded. The poster images consisted of a life-size image of a horse's face (true image), a version of the same image cut into 54 squares, which were then randomly rearranged (pixilated image) and a blank (white image) display of the same size as the other posters. Four observation periods were included in each of the two days of observation per treatment condition: 08:00-08:30 h, 10:00-10:30 h, 12:00-12:30 h and 16:00-17:00 h. The first observation period was followed by the provision of concentrate feed and forage, the second observation period by exercise, the third by further forage and the fourth by concentrate feed and forage. The horses' activities and positions in the box were scanned at 1 min intervals and the number of observations registering each activity and position was calculated as a percentage of the total number of observations for each observation period. Weaving was significantly less when the horses were provided with the image of a horse's face (mean percentage of observations +/- S.E.M.; 5.56 +/- 1.57), compared to both the pixilated (14.85 +/- 3.06) and white (20.52 +/- 4.12) images. Nodding was significantly less when provided with the true image of a horse (0.45 +/- 0.15) compared to the pixilated image (2.15 +/- 0.67). The pattern of weaving throughout the day differed from that of nodding, and together these results suggest that the two behaviours are not analogous. The presence of the image of the horse's face was associated with a significant increase in alertness (F112,2 = 11.31, p < 0.001) and recorded time spent looking at the poster(F112,2 = 3.46, p < 0.05). The timing of stereotypic head movements in the horse in this study suggests that they are not associated with boredom, or lack of stimulation but rather acute frustration.  
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  Notes Approved no  
  Call Number refbase @ user @ Serial 307  
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Author (down) Mech L.D. url  openurl
  Title Leadership in Wolf, Canis lupus, Packs. Type Journal Article
  Year 2000 Publication Canadian Field-Naturalist Abbreviated Journal Can Field Nat  
  Volume 114 Issue 2 Pages 259-263  
  Keywords Wolf, Canis lupus, leadership, behavior, foraging, movements, pup care, provisioning, sociality, reproduction, breeding, Northwest Territories.  
  Abstract I examine leadership in Wolf (Canis lupus) packs based on published observations and data gathered during summers from 1986 to 1998 studying a free-ranging pack of Wolves on Ellesmere Island that were habituated to my presence. The breeding male tended to initiate activities associated with foraging and travel, and the breeding female to initiate, and predominate in, pup care and protection. However, there was considerable overlap and interaction during these activities such that leadership could be considered a joint function. In packs with multiple breeders, quantitative information about leadership is needed.  
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  Notes Approved no  
  Call Number Equine Behaviour @ team @ Serial 4688  
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