Are body size and specific species colouration important cues for predator recognition by their potencial prey? Diplomová práce

I tested influence of a body size and overal colouration in feeders experiments on recognition of sparrowhawk (Accipiter nisus) by chosen species of passerine. Experiments were conducted in years 2015 ̶ 2018. I used a plush dummies which carried a specific featuress of raptor (hooked beak, claws) and specific features of genus Accipiter (yellow eyes, respectively yellow eyes and overal colouration). As a control, dummy of harmless pigeon was used. Smaller dummies (size of a great tit) were not recognized as a raptor regardless of colouration. Large dummies with colouration of great tit and pigeon were not recognized as a raptor as well. On a contrary, large dummy with colouration of robin was recognized as a raptor, respectively sparrowhawk. Most birds who were flying to the feeders, at first payed attention to global features (size, overal colouration). If these features belong to well-known harmless bird, then local features (particular) which characterize raptor or sparrowhawk had no effect. Birds did not pay attention to them. Therefore it depends on a context, in which potential local key features occure.V krmítkových experimentech jsem v letech 2015 ̶ 2018 pomocí plyšových atrap testovala vliv velikosti těla a celkového zbarvení na rozpoznávání krahujce obecného (Accipiter nisus) vybranými druhy pěvců. Atrapy nesly specifické znaky dravce (zahnutý zobák, pařáty) a specifické znaky rodu Accipiter (žluté oko, respektive žluté oko a celkové zbarvení). Jako kontrola byla použita atrapa neškodného holuba domácího. Atrapy zmenšené na velikost sýkory koňadry nebyly rozpoznány jako dravec bez ohledu na zbarvení. Jako dravec nebyly rozpoznány ani velké atrapy se zbarvením holuba a koňadry. Naopak jako dravec, respektive krahujec byla rozpoznána velká atrapa se zbarvením červenky. Většina ptáků přilétajících na krmítko věnuje přednostně pozornost globálním znakům (velikost, celkové zbarvení). Pokud tyto znaky patří známým neškodným ptákům, lokálním (dílčím) znakům charakterizujícím dravce, repsktive krahujce, pozornost nevěnují. Záleží tedy na kontextu, v jakém se potenciální lokální klíčové znaky vyskytují.Department of ZoologyKatedra zoologieFaculty of SciencePřírodovědecká fakult

Picture-object recognition in pigeons

Die Complementary Information Procedure präsentiert von Aust&Huber in 2006 kann die Bild-Objekt Erkennung in Tieren testen. Ich habe diese Methode an Teile von Schnecken angewandt und damit die Ergäbnisse der Verena Grabner aus 2010 ergäntzt. Der Head Vs Shell Vs Skin Test wurde wegen Identifikation relevanter Schneckenteile einer nicht-vertrauten Klasse eigesetzt. Zusätzliche Merkmalstests haben die Dimensionen identifiziert die zur Klassenvorhersage benutzt werden. Der Bildappendix ist nicht teil des PDFs.A Complementary Information Procedure presented by Aust&Huber in 2006 can test the Picture Object Recognition in animals. I employed this technique on parts of snails and extended the results presented in 2010 by Verena Grabner. For the identification of relevant parts of the unfamiliar class I employed the Head Vs Shell Vs Skin Test. Additional Feature Tests identified the dimensions that enable the prediction of a class. Image appendix is not part of the PDF

Comparison of individual's performance in a discrimination tasks with respect to the hierarchy status

Schopnost diskriminovat (rozlišit) stimuly je nejčastější testovanou kognitivní úlohou u holuba domácího (Columbia livia) v rámci zatím publikovaných prací. Dosud však nebyl dostatečně prozkoumán vliv personalitních vlastností na tuto schopnost. Tato práce se zabývá zjišťováním rozdílů v úspěšnosti jedinců mezi jednotlivými diskriminačními úlohami a analyzuje faktory včetně personality mající vliv na úspěšnost. Byla testována skupina 72 jedinců holuba domácího ve čtyřech na sebe navazujících úlohách: 1) diskriminace černé a bílé obrazovky ve Skinnerově boxu, 2) diskriminace černé a bílé plochy ve tvaru kruhu ve Skinnerově boxu, 3) diskriminace černého a bílého víčka v kleci, 4) diskriminace redukovaného černého a bílého stimulu na víčku v kleci. Kritérium úspěšnosti bylo stanoveno na 80 %. Ve Skinnerově boxu úlohu splnilo méně jedinců (6 % v první úloze, 20 % v druhé). V úlohách v kleci byl počet úspěšných jedinců vyšší (48 % ve třetí úloze, 50 % ve čtvrté). Úlohy se od sebe lišily prostředím a velikostí stimulů. Bylo zjištěno, že jedinci dokážou generalizovat pravidla diskriminace ve Skinnerově boxu, ale při výrazném zmenšení stimulů v kleci to již nezvládají. Dále byly analyzovány různé faktory, které by mohly ovlivňovat kognitivní úspěšnost. Bylo prokázáno, že úspěšnost ovlivňuje věk v době...The ability to discriminate stimuli is the most tested cognitive task in pigeons (Columbia livia f. domestica) within up to now published experiments. Up to now, the influence of personality traits on discrimination has been poorly studied. This thesis looks into the differences in success between individuals and discrimination tasks, and analyzes factors including personality traits influencing the success rate. In this experiment, the total of 72 individual pigeons were tested in four linked tasks: 1) discrimination of black and white screen in the Skinner's box, 2) discrimination of black and white circle patch in the Skinner's box, 3) discrimination of black and white lid in a cage and 4) discrimination of reduced black and white stimuli, placed on a lid, in the cage. The criterium of success was set on 80%. In the Skinner's box, the task were passed by lower number of individuals (6% in first, 20% in second) in comparsion with the cage (48% in third and 50% in fourth). The tasks differed in environment and size of stimuli. It has been determined, that te tested subjecs were able to generalise in the Skinner's box, with an expception when the stimuli was reduced. While testing, all factors that might have influenced the success rate were observed. It has been proved, that the success rate was...Department of ZoologyKatedra zoologiePřírodovědecká fakultaFaculty of Scienc

Perception of rotating objects by pigeons (Columba livia)

Für mobile Tiere ist sowohl die Fähigkeit, dreidimensionale Objekte als solche wahrzunehmen, als auch das Vermögen, diese trotz Änderung des Blickpunktes, Veränderung der Größe und unterschiedlicher Beleuchtung wieder zu erkennen, von großer Bedeutung. Die Frage, ob ein Tier fähig ist, dreidimensionale Information aus rein zweidimensionalen Darstellungen zu erschließen (wie es zum Beispiel bei Bildern dreidimensionaler Objekte der Fall ist, die auf einem Computer-Monitor präsentiert werden), wurde in den letzten Jahrzehnten der Wahrnehmungsforschung zunehmend zu einem zentralen Thema. Es ist durchaus möglich, dass zum Beispiel Tauben (Columba livia) zweidimensionale Bilder dreidimensionaler Objekte eher als beliebige Ansammlungen zweidimensionaler Merkmale sehen als diese als generalisierte 3-D-Repräsentationen wahrzunehmen. Sollten Tauben aber tatsächlich fähig sein, objektartige Repräsentationen zweidimensionaler Projektionen zu bilden, sollte die „dynamische Präsentation“ (d.h., das schnelle Abbilden aufeinander folgender Objekt-Ansichten) das Wiedererkennen bei diversen Stimulusmodifikationen erleichtern, da dynamische, kontinuierliche Veränderung der Perspektive die Integration einzelner Objektansichten zu einem dreidimensionalen Bild fördern kann. Diese Hypothese wurde in der vorliegenden Diplomarbeit getestet. Dazu wurden Tauben zuerst mit Hilfe einer Go-/No-Go-Prozedur darauf trainiert, zwischen 2-D-Projektionen eines Würfels und einer Pyramide zu unterscheiden. Diese wurden entweder als statische Einzelbilder oder in Rotation um die y-Achse präsentiert. Nachdem sie die Diskriminierungssaufgabe erlernt hatten, wurden den Vögeln in einer Reihe von Generalisationstests neue, modifizierte, Projektionen gezeigt. Die Änderungen betrafen unterschiedliche Objektmerkmale sowie die Art der Rotation, z.B. die Größe, die Oberflächen-Färbung, den Blickwinkel und die Reihenfolge der Einzelbilder einer dynamischen Sequenz. Die Ergebnisse zeigten, dass die meisten Arten von Transformationen das Wiedererkennen klar beeinträchtigten. Im Gegensatz zu einer Studie von COOK & KATZ (1999), die ein vergleichbares experimentelles Design verwendeten, fand ich weder Objektkonstanz über verschiedene Reiztransformationen, noch Anzeichen für einen „Dynamischen Superioritätseffekt“, das heißt, dass die Diskriminierungsleistung bei dynamischer gegenüber statischer Präsentation nicht verbessert war. Auch die Reihenfolge der Einzelbilder innerhalb einer dynamischen Sequenz schien für die Fähigkeit zur Objektunterscheidung nicht von Bedeutung zu sein. Die Fähigkeit, ein Objekt zu erkennen, war stark blickpunktabhängig und war bis zu einem gewissen Grad auch durch Größen- und Farbänderungen beeinflusst. Zusammengenommen legen die Ergebnisse den Schluss nahe, dass die Objektdiskriminierung auf gespeicherter zweidimensionaler Merkmalsinformation beruhte und nicht auf der Verwendung von dreidimensionalen Objektrepräsentationen. Sie bestätigen damit die Ansicht, dass das Wiedererkennen von Objekten von Mechanismen kontrolliert wird, die blickbasiert und nicht objektbasiert sind.Both perceiving the world as consisting of stable, unified, three-dimensional objects and recognising them despite changes in vantage point, size, and lighting conditions are fundamental abilities for all mobile animals. Whether an animal is able to retrieve 3-D information also from flat displays (e.g., 2-D projections of 3-D objects presented on a computer screen) has been a matter of interest in the last decades of research. For instance, pigeons (Columba livia) may perceive two-dimensional pictures of three-dimensional objects simply as random collections of flat, two-dimensional features instead of experiencing them as generalised 3-D representations. If, however, pigeons are indeed able to form object-like representations of two-dimensional displays, “dynamic presentation”, (i.e., presentation of views onto the object in rapid succession) should facilitate recognition across various stimulus modifications, since continuous dynamic change of perspective may help integrating individual views of an object into three-dimensional images. This hypothesis was tested in the current thesis. Pigeons were first trained in a go/no-go procedure to discriminate between 2-D projections of a cube and a pyramid, presented as static images or as rotating around the y-axis. When they had acquired the discrimination the birds were subjected to a series of transfer tests with new, modified, projections. These involved various featural and rotational transformations, such as novel size, altered surface colouration, novel viewpoint, and randomised rotation sequences. The results showed that most types of transformations clearly impaired recognition. In contrast to a study by COOK & KATZ (1999), who used a similar experimental design I could neither find object constancy across various stimulus transformations, nor any indication of a "dynamic superiority effect", i.e., discrimination performance was not improved by dynamic as compared to static presentation, and the order of images within a dynamic sequence was not crucial for object recognition. Furthermore, the ability to recognise an object was found to be strongly viewpoint-dependent and influenced also by modifications in size and colouration to some degree. Together, the results strongly suggest that object discrimination was based on stored 2-D featural information rather than on object-like 3-D representations. They are in line with the view that pigeons’ object recognition is controlled by view-based rather than object-based mechanisms

Visuelles Erkennen von Objekten mit Ausprägungsvarianzen

Computational visual object recognition has a big potential of application not only in the domain of automation technology, where visual object recognition is already established. A lot of other applications are imaginable, if more from the biological visual capabilities could be implemented. A special challenge consists in the recognition of real world objects having changing appearance. A universal object recognition system has to cope with that. However until now, it is unclear, which principles of functionality are used by biological object recognition. Scientific findings about that are still incomplete and allow no direct reproduction. Based on these findings, the only way to proceed is to assume principles of functionality and validate them in computational object recognition systems. In this contribution an explicit representation of changing appearance is investigated. For this purpose an object recognition system is built, which realises some new processing properties. The analysis of visual context is not realized with rigid filter masks as usual. Here context analysis is done by a new developed diffusion technique. The technique needs no pre-processing. A layer-wise representation of part objects with increasing complexity is built. For that no reduction of resolution is needed on the layers. A detection of a part object can depend on an arbitrary set of representations of underlying layers and not only from the one direct underlying. The evaluation of the object recognition system shows, that the explicit coding of changing appearance can be applied successfully

Brain Computations and Connectivity [2nd edition]

This is an open access title available under the terms of a CC BY-NC-ND 4.0 International licence. It is free to read on the Oxford Academic platform and offered as a free PDF download from OUP and selected open access locations. Brain Computations and Connectivity is about how the brain works. In order to understand this, it is essential to know what is computed by different brain systems; and how the computations are performed. The aim of this book is to elucidate what is computed in different brain systems; and to describe current biologically plausible computational approaches and models of how each of these brain systems computes. Understanding the brain in this way has enormous potential for understanding ourselves better in health and in disease. Potential applications of this understanding are to the treatment of the brain in disease; and to artificial intelligence which will benefit from knowledge of how the brain performs many of its extraordinarily impressive functions. This book is pioneering in taking this approach to brain function: to consider what is computed by many of our brain systems; and how it is computed, and updates by much new evidence including the connectivity of the human brain the earlier book: Rolls (2021) Brain Computations: What and How, Oxford University Press. Brain Computations and Connectivity will be of interest to all scientists interested in brain function and how the brain works, whether they are from neuroscience, or from medical sciences including neurology and psychiatry, or from the area of computational science including machine learning and artificial intelligence, or from areas such as theoretical physics