Browsing by Subject "DISCRIMINATION"

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  • Kellezi, Blerina; Guxholli, Aurora; Stevenson, Clifford; Ruth Helen Wakefield, Juliet; Bowe, Mhairi; Bridger, Kay (2021)
    Although Social Cure research shows the importance of family identification in one's ability to cope with stress, there remains little understanding of family responses to human rights violations. This is the first study to explore the role of family identity in the collective experience of such violations: meanings ascribed to suffering, family coping strategies, and family-based understandings of justice. Semi-structured interviews (N = 27) with Albanian dictatorship survivors were analysed using Social Identity Theory informed thematic analysis. The accounts reveal Social Cure processes at work, whereby family groups facilitated shared meaning-making, uncertainty reduction, continuity, resilience-building, collective self-esteem, and support, enhanced through common fate experiences. As well as being curative, families were contexts for Social Curse processes, as relatives shared suffering and consequences collectively, while also experiencing intergenerational injustice and trauma. Although seeking and achieving justice remain important, the preservation of family identity is one of the triumphs in these stories of suffering.
  • Marbouti, Marjan; Praks, Jaan; Antropov, Oleg; Rinne, Eero; Leppäranta, Matti (2017)
    Mapping of fast ice displacement and investigating sea ice rheological behavior is a major open topic in coastal ice engineering and sea ice modeling. This study presents first results on Sentinel-1 repeat-pass space borne synthetic aperture radar interferometry (InSAR) in the Gulf of Bothnia over the fast ice areas. An InSAR pair acquired in February 2015 with a temporal baseline of 12 days has been studied here in detail. According to our results, the surface of landfast ice in the study area was stable enough to preserve coherence over the 12-day baseline, while previous InSAR studies over the fast ice used much shorter temporal baselines. The advantage of longer temporal baseline is in separating the fast ice from drift ice and detecting long term trends in deformation maps. The interferogram showed displacement of fast ice on the order of 40 cm in the study area. Parts of the displacements were attributed to forces caused by sea level tilt, currents, and thermal expansion, but the main factor of the displacement seemed to be due to compression of the drift ice driven by southwest winds with high speed. Further interferometric phase and the coherence measurements over the fast ice are needed in the future for understanding sea ice mechanism and establishing sustainability of the presented InSAR approach for monitoring dynamics of the landfast ice with Sentinel-1 data.
  • Mattar, Marcelo G.; Olkkonen, Maria; Epstein, Russell A.; Aguirre, Geoffrey K. (2018)
    Perception and neural responses are modulated by sensory history. Visual adaptation, an example of such an effect, has been hypothesized to improve stimulus discrimination by decorrelating responses across a set of neural units. While a central theoretical model, behavioral and neural evidence for this theory is limited and inconclusive. Here, we use a parametric 3D shape-space to test whether adaptation decorrelates shape representations in humans. In a behavioral experiment with 20 subjects, we find that adaptation to a shape class improves discrimination of subsequently presented stimuli with similar features. In a BOLD fMRI experiment with 10 subjects, we observe that adaptation to a shape class decorrelates the multivariate representations of subsequently presented stimuli with similar features in object-selective cortex. These results support the long-standing proposal that adaptation improves perceptual discrimination and decorrelates neural representations, offering insights into potential underlying mechanisms.
  • Lindstrom, R.; Lepistö-Paisley, T.; Makkonen, T.; Reinvall, O.; Nieminen-von Wendt, T.; Alen, R.; Kujala, T. (2018)
    Objective: The present study explored the processing of emotional speech prosody in school-aged children with autism spectrum disorders (ASD) but without marked language impairments (children with ASD [no LI]). Methods: The mismatch negativity (MMN)/the late discriminative negativity (LDN), reflecting pre-attentive auditory discrimination processes, and the P3a, indexing involuntary orienting to attention-catching changes, were recorded to natural word stimuli uttered with different emotional connotations (neutral, sad, scornful and commanding). Perceptual prosody discrimination was addressed with a behavioral sound-discrimination test. Results: Overall, children with ASD (no LI) were slower in behaviorally discriminating prosodic features of speech stimuli than typically developed control children. Further, smaller standard-stimulus event related potentials (ERPs) and MMN/LDNs were found in children with ASD (no LI) than in controls. In addition, the amplitude of the P3a was diminished and differentially distributed on the scalp in children with ASD (no LI) than in control children. Conclusions: Processing of words and changes in emotional speech prosody is impaired at various levels of information processing in school-aged children with ASD (no LI). Significance: The results suggest that low-level speech sound discrimination and orienting deficits might contribute to emotional speech prosody processing impairments observed in ASD. (C) 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
  • Sarkamo, Teppo; Tervaniemi, Mari; Soinila, Seppo; Autti, Taina; Silvennoinen, Heli M.; Laine, Matti; Hietanen, Marja; Pihko, Elina (2010)
    Acquired amusia is a common disorder after damage to the middle cerebral artery (MCA) territory. However, its neurocognitive mechanisms, especially the relative contribution of perceptual and cognitive factors, are still unclear. We studied cognitive and auditory processing in the amusic brain by performing neuropsychological testing as well as magnetoencephalography (MEG) measurements of frequency and duration discrimination using magnetic mismatch negativity (MMNm) recordings. Fifty-three patients with a left (n = 24) or right (n = 29) hemisphere MCA stroke (MRI verified) were investigated 1 week, 3 months, and 6 months after the stroke. Amusia was evaluated using the Montreal Battery of Evaluation of Amusia (MBEA). We found that amusia caused by right hemisphere damage (RHD), especially to temporal and frontal areas, was more severe than amusia caused by left hemisphere damage (LHD). Furthermore, the severity of amusia was found to correlate with weaker frequency MMNm responses only in amusic RHD patients. Additionally, within the RHD subgroup, the amusic patients who had damage to the auditory cortex (AC) showed worse recovery on the MBEA as well as weaker MMNm responses throughout the 6-month follow-up than the non-amusic patients or the amusic patients without AC damage. Furthermore, the amusic patients both with and without AC damage performed worse than the non-amusic patients on tests of working memory, attention, and cognitive flexibility. These findings suggest domain-general cognitive deficits to be the primary mechanism underlying amusia without AC damage whereas amusia with AC damage is associated with both auditory and cognitive deficits.
  • Pentikäinen, Emmi; Kimppa, Lilli; Makkonen, Tommi; Putkonen, Mikko Tapani; Pitkäniemi, Anni; Salakka, Ilja Juhana; Paavilainen, Petri; Tervaniemi, Mari; Särkämö, Teppo (2022)
    Aging is accompanied by difficulties in auditory information processing, especially in more complex sound environments. Choir singing requires efficient processing of multiple sound features and could, therefore, mitigate the detrimental effects of aging on complex auditory encoding. We recorded auditory event-related potentials during passive listening of sounds in healthy older adult (>= 60 years) choir singers and nonsinger controls. We conducted a complex oddball condition involving encoding of abstract regularities in combinations of pitch and location features, as well as in two simple oddball conditions, in which only either the pitch or spatial location of the sounds was varied. We analyzed change-related mismatch negativity (MMN) and obligatory P1 and N1 responses in each condition. In the complex condition, the choir singers showed a larger MMN than the controls, which also correlated with better performance in a verbal fluency test. In the simple pitch and location conditions, the choir singers had smaller N1 responses compared to the control subjects, whereas the MMN responses did not differ between groups. These results suggest that regular choir singing is associated both with more enhanced encoding of complex auditory regularities and more effective adaptation to simple sound features.
  • Pulliainen, Outi Unni Inkeri; Bos, Nicky Peter Maria; d'Ettorre, Patrizia; Sundström, Liselotte (2018)
    The ability to distinguish friends from foe is a widespread phenomenon among social animals. In ants, recognition of intruders is important for the maintenance of colony integrity and survival. Intruders are typically adult, but the acceptance of non-nestmate brood could result in severe fitness costs, depending on the caste of the brood. Accepting non-nestmate worker brood may not carry a cost, as they should not drain resources of the adoptive colony but may instead add to the workforce. Sexual brood, however, would typically not contribute to colony performance, yet require resources, and should thus be rejected. Here, we tested whether workers of the narrow-headed ant, Formica exsecta, which strongly discriminate between adult nestmates and non-nestmates, also discriminate between nestmate and non-nestmate pupae. Furthermore, we investigated whether the caste of the brood (workers/sexuals) affects discrimination. We carried out analysis of surface chemicals to investigate whether the chemical distance between colonies was associated with the propensity to accept non-nestmate pupae. We show that worker pupae were retrieved irrespective of their origin, whereas nestmate sexual pupae were retrieved at a slightly higher rate than non-nestmates. Our chemical data, however, suggest that both the reproductive and the worker brood carry sufficient chemical information for discrimination, as they both express colony signatures. However, this information is acted upon only in the case of sexual brood. Our results thus suggest that workers selectively capitalize on the chemical information in agreement with fitness predictions, albeit to a lower extent than during discrimination between adult individuals.
  • Renvik (Mähönen), Tuuli Anna; Manner, Joel; Vetik, Raivo; Sam, David; Jasinskaja-Lahti, Inga (2020)
    This survey study utilized a person-oriented approach to explore the patterns of socio-political integration among Russian-speaking minority group members in three neighboring countries in the Baltic area: Estonia (n = 482), Finland (n = 252), and Norway (n = 215). Three profiles were obtained in all countries: critical integration, separation, and assimilation. In the whole sample, critical integration was the most common acculturation profile. After the profiles were established, they were examined vis-a-vis citizenship and integration context to see, whether and to what extent, the objective (i.e., citizenship) and subjective (i.e., perceived social status and sense of belonging) socio-political integration of Russian-speakers corresponded with each other. Critical integration and separation were the most common profiles among participants holding national citizenship of the country of residence, while foreign citizenship was not related to any specific profile. Separation was rare among participants holding dual citizenship, but it was the most common profile among participants with undetermined citizenship. Also, intergroup context was associated with socio-political integration: critical integration and separation were the most common profiles of Russian-speakers in Estonia, critical integration and assimilation profiles in Finland, and assimilation profile in Norway. The results are discussed in relation to previous variable-oriented research and official integration policies of the countries studied.
  • Lämsä, Anna-Maija; Mattila, Markku; Lähdesmäki, Merja; Suutari, Timo (2019)
    Purpose In this paper, the following research question is addressed: Why do business organisations recruit employees with a foreign background? This was examined in terms of the values that guide organisations and their management. The paper aims to discuss this issue. Design/methodology/approach The study focused on two businesses in Finland that are pioneers in the recruitment of immigrants. A case study approach was adopted. The research data consist of interviews and documentary data. The data were analysed using content analysis in accordance with grounded theory. Findings Companies can act as an enabling force in the integration of immigrants into the local labour market, especially when the company's value basis extends beyond only economic values. Research limitations/implications - The study was conducted only in two case companies in Finland. Practical implications - Companies have the potential to affect local people's attitudes towards immigrants as workers. This is important because many western societies are likely to face a labour shortage in the future due to the ageing population and low birth rate. Originality/value Prior research has mostly investigated the topic from the viewpoints of the immigrants themselves and of policy makers. The value of this study is that it makes the employers' viewpoint visible. The dominant theories applied in the field of immigrant recruitment are inadequate to explain employers' behaviour because of their underlying assumption of the overwhelming importance of economic values in decision making.
  • Viinikka, Arto; Hurskainen, Pekka; Keski-Saari, Sarita; Kivinen, Sonja; Tanhuanpää, Topi; Mäyrä, Janne; Poikolainen, Laura; Vihervaara, Petteri; Kumpula, Timo (2020)
    Sustainable forest management increasingly highlights the maintenance of biological diversity and requires up-to-date information on the occurrence and distribution of key ecological features in forest environments. European aspen (Populus tremulaL.) is one key feature in boreal forests contributing significantly to the biological diversity of boreal forest landscapes. However, due to their sparse and scattered occurrence in northern Europe, the explicit spatial data on aspen remain scarce and incomprehensive, which hampers biodiversity management and conservation efforts. Our objective was to study tree-level discrimination of aspen from other common species in northern boreal forests using airborne high-resolution hyperspectral and airborne laser scanning (ALS) data. The study contained multiple spatial analyses: First, we assessed the role of different spectral wavelengths (455-2500 nm), principal component analysis, and vegetation indices (VI) in tree species classification using two machine learning classifiers-support vector machine (SVM) and random forest (RF). Second, we tested the effect of feature selection for best classification accuracy achievable and third, we identified the most important spectral features to discriminate aspen from the other common tree species. SVM outperformed the RF model, resulting in the highest overall accuracy (OA) of 84% and Kappa value (0.74). The used feature set affected SVM performance little, but for RF, principal component analysis was the best. The most important common VI for deciduous trees contained Conifer Index (CI), Cellulose Absorption Index (CAI), Plant Stress Index 3 (PSI3), and Vogelmann Index 1 (VOG1), whereas Green Ratio (GR), Red Edge Inflection Point (REIP), and Red Well Position (RWP) were specific for aspen. Normalized Difference Red Edge Index (NDRE) and Modified Normalized Difference Index (MND705) were important for coniferous trees. The most important wavelengths for discriminating aspen from other species included reflectance bands of red edge range (724-727 nm) and shortwave infrared (1520-1564 nm and 1684-1706 nm). The highest classification accuracy of 92% (F1-score) for aspen was achieved using the SVM model with mean reflectance values combined with VI, which provides a possibility to produce a spatially explicit map of aspen occurrence that can contribute to biodiversity management and conservation efforts in boreal forests.
  • Savonen, Jenni; Kataja, Kati; Sakki, Inari (2022)
    This article draws from a social representations approach (SRA) to present a qualitative inquiry of identity construction in interaction and as part of the social context. We argue that the concept of positioning, inherent to our understanding of SRA, provides a bridge between social representations and identities. Focusing on societally marginalised groups and with illustrative interview samples gathered from two different studies in Finland, this article aims to show how people who use hard drugs position themselves within dominating social representations of 'addict', 'junkie' and 'polydrug user'. Two ways of positioning are employed to negotiate with negative social representations: resistance and partial acceptance. 'Distancing from the worst' as a way of positioning characterises resistance and illustrates how a positive identity is constructed by describing the 'ingroup other' in negative ways, enabling justification of why the responded is not like that. In contrast, 'facing the inescapable' as a way of positioning illustrates partial acceptance that is engaged when people feel they cannot control their use or their lives more generally and cannot justify another position than that of a prototypical user. Our article advances the literature on the role of positioning within representational fields as enabling individuals to reject, challenge or accept the dominating social representations, while at the same time serving as a resource to cope with identity threats and maintain a positive identity.
  • Virtala, Paula; Huotilainen, Minna; Lilja, Esa; Ojala, Juha; Tervaniemi, Mari (2018)
    GUITAR DISTORTION USED IN ROCK MUSIC MODIFIES a chord so that new frequencies appear in its harmonic structure. A distorted dyad (power chord) has a special role in heavy metal music due to its harmonics that create a major third interval, making it similar to amajor chord. We investigated how distortion affects cortical auditory processing of chords in musicians and nonmusicians. Electric guitar chords with or without distortion and with or without the interval of the major third (i.e., triads or dyads) were presented in an oddball design where one of them served as a repeating standard stimulus and others served as occasional deviants. This enabled the recording of event-related potentials (ERPs) of the electroencephalogram (EEG) related to deviance processing (the mismatch negativity MMN and the attention-related P3a component) in an ignore condition. MMN and P3a responses were elicited in most paradigms. Distorted chords in a non-distorted context only elicited early P3a responses. However, the power chord did not demonstrate a special role in the level of the ERPs. Earlier and larger MMN and P3a responses were elicited when distortion was modified compared to when only harmony (triad vs. dyad) was modified between standards and deviants. The MMN responses were largest when distortion and harmony deviated simultaneously. Musicians demonstrated larger P3a responses than nonmusicians. The results suggest mostly independent cortical auditory processing of distortion and harmony in Western individuals, and facilitated chord change processing in musicians compared to nonmusicians. While distortion has been used in heavy rock music for decades, this study is among the first ones to shed light on its cortical basis.
  • Astikainen, Piia; Mällo, Tanel; Ruusuvirta, Timo; Naatanen, Risto (2014)
  • Nowak, Kamila; Oron, Anna; Szymaszek, Aneta; Leminen, Miika; Naatanen, Risto; Szelag, Elzbieta (2016)
    The present study investigates age-related changes in duration discrimination in millisecond time domain. We tested young (N = 20, mean age = 24.5, SD = 2.97) and elderly (N = 20, mean age = 65.2, SD = 2.94) subjects using the mismatch negativity (MMN) paradigm. White-noise bursts of two different durations (50 and 10 ms) were presented in two oddball blocks. In one block (Increment Condition), the repetitive sequence of 10 ms standards was interspersed by occasional 50 ms deviants. In the Decrement Condition, the roles of the two stimuli were reversed. We analyzed the P1-N1 complex, MMN and P3a and found the effect of age for all these components. Moreover, the impact of stimulus presentation condition (increment/decrement) was observed for MMN and P3a. Our results confirmed the previous evidence for deteriorated duration discrimination in elderly people. Additionally, we found that this effect may be influenced by procedural factors.
  • Arstila, Valtteri; Georgescu, Alexandra L.; Lunn, Daniel; Noreika, Valdas; Falter-Wagner, Christine M.; Pesonen, Henri (2020)
    Essential for successful interaction with the environment is the human capacity to resolve events in time. Typical event timing paradigms are judgements of simultaneity (SJ) and of temporal order (TOJ). It remains unclear whether SJ and TOJ are based on the same underlying mechanism and whether there are fixed thresholds for resolution. The current study employed four visual event timing task versions: horizontal and vertical SJ and TOJ. Binary responses were analysed using multilevel binary regression modelling. Modulatory effects of potential explanatory variables on event timing perception were investigated: (1) Individual factors (sex and age), (2) temporal factors (SOA, trial number, order of experiment, order of stimuli orientation, time of day) and (3) spatial factors (left or right stimulus first, top or bottom stimulus first, horizontal vs. vertical orientation). The current study directly compares for the first time, performance on SJ and TOJ tasks using the same paradigm and presents evidence that a variety of factors and their interactions selectively modulate event timing functions in humans, explaining the variance found in previous studies. We conclude that SJ and TOJ are partially independent functions, because they are modulated differently by individual and contextual variables.
  • Mäkelin, Saara Elisa Iines; Villnäs, Anna (2022)
    Benthic fauna plays an important role in mediating biogeochemical cycles in coastal areas by storing carbon (C), nitrogen (N), and phosphorus (P) in their body tissues at theoretically homeostatic rates. To maintain homeostasis, the benthic consumers need to be in balance with their resource supply or alter their stoichiometric traits in response to environmental change. However, we lack an understanding regarding the potential variation in the C : N : P content ratios of benthic consumers, especially in marine coastal areas where stoichiometric shifts in macrofauna could have strong effects on sediment carbon and nutrient cycling. By monitoring two sites over a year, we quantified the magnitude and temporal stability of benthic faunal carbon and nutrient pools in coastal soft-sediment habitats. Our results show that benthic fauna is not strictly homeostatic, but instead expresses temporal variation in C : N : P content. These aquatic consumers undergo ontogenetic changes in diet and morphology, which alter their stoichiometric characteristics. In addition, the faunal C : N : P ratios showed strong seasonal variation at both species and community level, and our results suggest that the stoichiometric traits of benthic consumers shift in response to food sources and environmental conditions. The ability to adapt to varying stoichiometric conditions is essential in face of the growing C : N : P imbalance occurring in marine and coastal ecosystems as a consequence of anthropogenic activities. Therefore, it is critically important to identify the stoichiometric plasticity of different species, before environmental change causes a shift in benthic community composition that will alter functions on an ecosystem level.
  • Kliuchko, Marina; Brattico, Elvira; Gold, Benjamin P.; Tervaniemi, Mari; Bogert, Brigitte; Toiviainen, Petri; Vuust, Peter (2019)
    Learning, attention and action play a crucial role in determining how stimulus predictions are formed, stored, and updated. Years-long experience with the specific repertoires of sounds of one or more musical styles is what characterizes professional musicians. Here we contrasted active experience with sounds, namely long-lasting motor practice, theoretical study and engaged listening to the acoustic features characterizing a musical style of choice in professional musicians with mainly passive experience of sounds in laypersons. We hypothesized that long-term active experience of sounds would influence the neural predictions of the stylistic features in professional musicians in a distinct way from the mainly passive experience of sounds in laypersons. Participants with different musical backgrounds were recruited: professional jazz and classical musicians, amateur musicians and non-musicians. They were presented with a musical multi-feature paradigm eliciting mismatch negativity (MMN), a prediction error signal to changes in six sound features for only 12 minutes of electroencephalography (EEG) and magnetoencephalography (MEG) recordings. We observed a generally larger MMN amplitudes-indicative of stronger automatic neural signals to violated priors-in jazz musicians (but not in classical musicians) as compared to non-musicians and amateurs. The specific MMN enhancements were found for spectral features (timbre, pitch, slide) and sound intensity. In participants who were not musicians, the higher preference for jazz music was associated with reduced MMN to pitch slide (a feature common in jazz music style). Our results suggest that long-lasting, active experience of a musical style is associated with accurate neural priors for the sound features of the preferred style, in contrast to passive listening.
  • Kärenlampi, Kimmo; Heinonen, Jussi S.; Kontinen, Asko; Hanski, Eero; Huhma, Hannu (2021)
    The origin of ferroan A-type granites in anorogenic tectonic settings remains a long-standing petrological puzzle. The proposed models range from extreme fractional crystallization of mantle-derived magmas to partial melting of crustal rocks, or involve combination of both. In this study, we apply whole-rock chemical and Sm-Nd isotopic compositions and thermodynamically constrained modeling (Magma Chamber Simulator, MCS) to decipher the genesis of a suite of A1-type peralkaline to peraluminous granites and associated intermediate rocks (monzodiorite-monzonite, syenite) from the southwestern margin of the Archean Karelia craton, central Finland, Fennoscandian Shield. These plutonic rocks were emplaced at ca. 2.05 Ga during an early stage of the break-up of the Karelia craton along its western margin and show trace element affinities to ocean island basalt-type magmas. The intermediate rocks show positive epsilon Nd(2050 Ma) values (+1.3 to +2.6), which are only slightly lower than the estimated contemporaneous depleted mantle value (+3.4), but much higher than average epsilon Nd(2050 Ma) of Archean TTGs (-10) in the surrounding bedrock, indicating that these rocks were essentially derived from a mantle source. The epsilon Nd(2050 Ma) values of the peralkaline and peraluminous granite samples overlap (-0.9 to +0.6 and -3.2 to +0.9, respectively) and are somewhat lower than those in the intermediate rocks, suggesting that the mafic magmas parental to granite must have assimilated some amount of older Archean continental crust during their fractionation, which is consistent with the continental crust-like trace element signatures of the granite members. The MCS modeling indicates that fractional crystallization of mantle-derived magmas can explain the major element characteristics of the intermediate rocks. The generation of the granites requires further fractional crystallization of these magmas coupled with assimilation of Archean crust. These processes took place in the middle to upper crust (-2-4 kbar, -7-15 km) and involved crystallization of large amounts of clinopyroxene, plagioclase and olivine. Our results highlight the importance of coupled FC-AFC processes in the petrogenesis of A-type magmas and support the general perception that magmas of A-type ferroan granites become more peraluminous by assimilation of crust. They further suggest that variable fractionation paths of the magmas upon the onset of assimilation may explain the broad variety of A-type felsic and intermediate igneous rocks that is often observed emplaced closely in time and space within the same igneous complex.
  • Thorogood, Rose; Kilner, Rebecca M.; Rasmussen, Justin L. (2017)
    Many brood parasites rely on mimicry to prevent the detection of their eggs by hosts, yet most Australasian cuckoo species lay darkly colored eggs while the eggs of their hosts are pale and speckled. In the dimly lit nests of their hosts, these cuckoo eggs may appear cryptic; however, it is unclear if this disguise has evolved to fool hosts or other cuckoos. Recent work suggests that in at least one species of bronze-cuckoo, cuckoos are more likely to reject conspicuous eggs than are hosts, but it remains unclear whether this is common across the species group. Here, we present field experiments on the sole host of the Shining Bronze-Cuckoo (Chalcites lucidus lucidus) in New Zealand, the Grey Gerygone (Gerygone igata; known locally as the Grey Warbler), that explored whether this host ignores cuckoo eggs because they are cryptic. Using an avian vision model, we showed that Shining Bronze-Cuckoo eggs were variable in their conspicuousness, but were more cryptic in host nests than the host's eggs. We then experimentally parasitized all available clutches with model eggs that mimicked darkly or brightly colored cuckoo eggs, or were of maximum conspicuousness (white) as determined by visual modeling. Hosts never rejected our model eggs, nor cuckoo eggs when naturally parasitized. Instead, only cuckoos rejected model eggs: In 3 out of 4 experimental nests that were subsequently parasitized, the model egg was taken and replaced by a cuckoo's egg. Together, these data and previous experiments suggest that competition among cuckoos, rather than rejection by hosts, provides a stronger selection pressure for the evolution of cryptic eggs across the genus Chalcites.