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14 záznamů v Medvik Filtry

Článek

Anti-parasitic egg rejection by great reed warblers (Acrocephalus arundinaceus) tracks differences along an eggshell color gradient

Abolins-Abols, Mikus
Autor Abolins-Abols, Mikus Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois, Urbana-Champaign, USA. Electronic address: abolins@illinois.edu
Hanley, Daniel
Autor Hanley, Daniel Department of Biology and Environmental Sciences, Long Island University - Post, USA
Moskát, Csaba
Autor Moskát, Csaba MTA-ELTE-MTM Ecology Research Group: a joint research group of the Hungarian Academy of Sciences, the Eötvös Loránd University, and the Hungarian Natural History Museum, Budapest, Hungary
Grim, Tomáš
Autor Grim, Tomáš Na Orátě 497, 78361, Hlubočky, Czech Republic
Hauber, Mark E
Autor Hauber, Mark E Department of Evolution, Ecology, and Behavior, School of Integrative Biology, University of Illinois, Urbana-Champaign, USA

Behavioural processes. 2019 ; 166 (-) : 103902. [pub] 20190705

Behav Processes
ISSN 1872-8308
Medvik
Zdroj

One of the most effective defenses against avian brood parasitism is the rejection of the foreign egg from the host's nest. Until recently, most studies have tested whether hosts discriminate between own and foreign eggs based on the absolute differences in avian-perceivable eggshell coloration and maculation. However, recent studies suggest that hosts may instead contrast egg appearances across a directional eggshell color gradient. We assessed which discrimination rule best explained egg rejection by great reed warblers Acrocephalus arundinaceus, a frequent host to an egg-mimetic race of common cuckoos Cuculus canorus. We deployed 3D-printed model eggs varying in blue-green to brown coloration and in the presence of maculation. Using visual modeling, we calculated the absolute chromatic and achromatic just-noticeable differences (JNDs), as well as directional JNDs across a blue-green to brown egg color gradient, between host and model eggs. While most model eggs were rejected by great reed warblers, browner eggs were rejected with higher probability than more blue-green eggs, and the rejection probability did not depend on maculation. Directional egg color discrimination shown here and in a suite of recent studies on other host species may shape the cognitive decision rules that hosts use to recognize foreign eggs and affect the course of evolution in parasitic egg mimicry.

Článek online

The power of red: The influence of colour on evaluation and failure - A replication

Acta psychologica. 2019 ; 198 (-) : 102873. [pub] 20190622

Acta Psychol (Amst)
ISSN 1873-6297
Medvik
Zdroj

This replication of a study by >Rutchick, Slepian, and Ferris (2010) examines the influence of the colour of a pen on the activation of associations with failure and the focus on errors. We assigned two tasks to 198 students who completed them using either a red or a blue pen. The students were instructed to complete several word stems in the first task. In the second, we asked them to mark mistakes in a text. The participants using red pens completed significantly more word stems with words associated with failure than those using blue pens. The participants using red pens also marked significantly more mistakes in a text than those using blue pens. Our results support the findings of the original study and the hypothesized influence of the colour red in inducing a higher activation of associations with failure and a heightened focus on mistakes. Our study further contributes to research in this area in that it takes into account the participants' field of study and creates an explicit achievement context in which the observed phenomenon is most prevalent.

Článek online

Long-term versus short-term consistency in the grapheme-colour synaesthesia: Grapheme-colour pairings can change in adulthood

Attention, perception & psychophysics. 2019 ; 81 (6) : 1805-1812. [pub] -

Atten Percept Psychophys
ISSN 1943-393X
Medvik
Zdroj

The aim of the article is to examine the stability of grapheme-colour matchings in adulthood. We carried out a panel study using computerized tests to measure short-term and long-term consistency. We conducted three testing rounds during 1 year and a half with a resulting sample of 26 synaesthetes. Our results suggest that the colours associated with individual graphemes can change substantially (e.g. from "salmon" to "aquamarine") even during this relatively short time period. Based on a linear mixed model, we further argue that short-term and long-term consistency should be distinguished because these scores tend to differ. These results thus complement previous findings on the issue of grapheme-colour consistency and have important consequences for the study of synaesthesia in the future.

Článek

Altered perceptual binding in Gilles de la Tourette syndrome

Cortex. 2016 ; 83 (-) : 160-6. [pub] 20160730

ISSN 1973-8102
Medvik
Zdroj

Gilles de la Tourette syndrome (GTS) is a common multifaceted neuropsychiatric disorder. Research in GTS has traditionally focussed on mechanisms underlying changes in motor processes in these patients. There is, however, growing interest in GTS related sensory phenomena. According to the Theory of Event-coding (TEC), sensory stimuli do not only serve representational functions but also action-related functions. In the current study, we use the TEC framework to examine whether the way perceptual features are processed is altered in GTS. The results show that basic perceptual processes differ between GTS patients and healthy controls which might be central for the understanding of this disorder. Details or features of perceptual objects were less bound in GTS suggesting that perceptual features integration is attenuated in them. Behavioural findings were unrelated to patient characteristics implying that they might represent trait abnormalities. It is possible that altered perceptual processing in GTS is due to a long-range under-connectivity of parietal areas with other brain regions repeatedly been described in these patients.