scholarly journals DO BUDGERIGARS (MELOPSITTACUS UNDULATUS) PERCEIVE THE DELBOEUF ILLUSION?: A PRELIMINARY STUDY WITH A SIMULTANEOUS DISCRIMINATION TASK

PSYCHOLOGIA ◽  
2016 ◽  
Vol 59 (2-3) ◽  
pp. 121-135
Author(s):  
Sota WATANABE ◽  
Yuriko HASE ◽  
Noriyuki NAKAMURA
2014 ◽  
Author(s):  
Christian Nawroth ◽  
Eberhard von Borell

Finding and relocating food sources is not only crucial for individuals in changing natural environments - it is also of importance in domestic animals under husbandry conditions, for instance to reduce stress when transferring animals into new housing conditions. This study makes a first attempt by investigating young pigs´ use of conflicting spatial and feature cues in a simultaneous discrimination task. In a training phase, subjects (n = 9) first learned to approach a food container with distinct spatial and feature cues. In a subsequent test phase, spatial and feature cues were brought into conflict. Results show that young pigs significantly preferred to approach the spatial position rather than the feature cue of a food container – at least for the visual domain - while inter-individual differences in choice behaviour suggest that animals recognized the changed context. However, the actual test setup did not exclude alternatives to the use of spatial cues, e.g. instrumental learning. The results may contribute to a better understanding of learning mechanisms in domestic pigs and could be used to improve husbandry designs, reduce stress levels after transfer and may prove to be helpful in designing further test paradigms investigating discriminative learning abilities in the domestic pig.


Perception ◽  
1988 ◽  
Vol 17 (4) ◽  
pp. 549-554 ◽  
Author(s):  
Peter G Hepper

In reply to a suggestion made by Galton in 1875, the ability of dogs to discriminate between the odour of human twins was investigated. In a matching-to-sample simultaneous discrimination task, dogs were tested on their ability to discriminate odours from twins differing only in genetic relatedness or only in environmental factors, particularly diet, or from twins identical in both genetic relatedness and environmental factors. Dogs could discriminate between the odours from twins who differed only in environmental factors and between the odours of twins who differed only in genetic relatedness. However, they were unable to discriminate between odours produced by infant twins identical in both genetic relatedness and environmental factors. Thus twins may be discriminated by dogs as long as they differ in genetic relatedness or environmental factors. The possible source of discriminable odours is discussed and how the effects of genes and environment are mediated considered.


2014 ◽  
Author(s):  
Christian Nawroth ◽  
Eberhard von Borell

Finding and relocating food sources is not only crucial for individuals in changing natural environments - it is also of importance in domestic animals under husbandry conditions, for instance to reduce stress when transferring animals into new housing conditions. This study makes a first attempt by investigating young pigs´ use of conflicting spatial and feature cues in a simultaneous discrimination task. In a training phase, subjects (n = 9) first learned to approach a food container with distinct spatial and feature cues. In a subsequent test phase, spatial and feature cues were brought into conflict. Results show that young pigs significantly preferred to approach the spatial position rather than the feature cue of a food container – at least for the visual domain - while inter-individual differences in choice behaviour suggest that animals recognized the changed context. However, the actual test setup did not exclude alternatives to the use of spatial cues, e.g. instrumental learning. The results may contribute to a better understanding of learning mechanisms in domestic pigs and could be used to improve husbandry designs, reduce stress levels after transfer and may prove to be helpful in designing further test paradigms investigating discriminative learning abilities in the domestic pig.


2017 ◽  
Vol 4 (3) ◽  
pp. 365-377 ◽  
Author(s):  
Maria Santaca ◽  
Barbara Regaiolli ◽  
Maria Elena Miletto Petrazzini ◽  
Caterina Spiezio ◽  
Christian Agrillo

1977 ◽  
Vol 45 (1) ◽  
pp. 27-33 ◽  
Author(s):  
Karen L. Hartlep ◽  
G. Alfred Forsyth

An operant technique was used to train 10-wk.-old infants on a simultaneous discrimination task with a checkerboard cube and a bull's-eye sphere presented in a stationary form. Discrimination testing with the objects in motion and with the objects stationary indicated that infants are able to discriminate between simultaneously presented objects whether stationary or in motion. The results are contrasted to T. G. R. Bower's assessment of infants' utilization of features in perceiving moving objects.


Author(s):  
John H.L. Watson ◽  
John L. Swedo ◽  
R.W. Talley

A preliminary study of human mammary carcinoma on the ultrastructural level is reported for a metastatic, subcutaneous nodule, obtained as a surgical biopsy. The patient's tumor had responded favorably to a series of hormonal therapies, including androgens, estrogens, progestins, and corticoids for recurring nodules over eight years. The pertinent nodule was removed from the region of the gluteal maximus, two weeks following stilbestrol therapy. It was about 1.5 cms in diameter, and was located within the dermis. Pieces from it were fixed immediately in cold fixatives: phosphate buffered osmium tetroxide, glutaraldehyde, and paraformaldehyde. Embedment in each case was in Vestopal W. Contrasting was done with combinations of uranyl acetate and lead hydroxide.


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