896 research outputs found

    Conspecific Recognition in the Chimpanzee (Pan troglodytes): Cardiac Responses to Significant Others

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    The ability of a chimpanzee (Pan troglodytes) to recognize photographs of conspecifics was evaluated with heart-rate measures. Heart rate was recorded before, during, and after viewing photographs of an aggressive chimpanzee, a friendly companion animal, and an unfamiliar chimpanzee. The subject displayed a differential pattern of heart-rate response to the stimulus animals, without prior experience with the photographs. Responses to the aggressive animal were acceleratory, which suggests a defensive response. Respiratory sinus arrhythmia suggested that this response was associated with sympathetic activation. In contrast, responses to the familiar animal were minimal, whereas cardiac deceleration was observed in response to the strange chimp, which likely reflects an orienting response. Results suggest the chimpanzee is able to recognize photographs of individual conspecifics and that heart-rate change can reflect the nature of established social relationships between chimpanzees

    Numerical Competence in a Chimpanzee (Pan troglodytes)

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    A chimpanzee (Pan troglodytes), trained to count foods and objects by using Arabic numbers, demonstrated the ability to sum arrays of 0-4 food items placed in 2 of 3 possible sites. To address representational use of numbers, we next baited sites with Arabic numbers as stimuli. In both cases performance was significantly above chance from the first sessions, which suggests that without explicit training in combining arrays, the animal was able to select the correct arithmetic sum for arrays of foods or Arabic numbers under novel test conditions. These findings demonstrate that counting strategies and the representational use of numbers lie within the cognitive domain of the chimpanzee and compare favorably with the spontaneous use of addition algorithms demonstrated in preschool children

    Specificity of the Cardiac Response to Conspecific Vocalizations in Chimpanzees

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    Heart rate measures were used to examine the functional response of young chimpanzees and orangutans to acoustic stimuli, including white noise and chimpanzee vocalizations (threat, stress, and alarm). The initial response of the animals to all stimuli was characterized by a prominent cardiac deceleration and an increase in heart period variability. The deceleratory responses persisted with repeated presentations of the noise, stress, and alarm stimuli. In contrast, the response of chimpanzees to the conspecific threat stimulus reverted over trials to a notable cardiac acceleration. This acceleratory response was not attributable to potential patterns of evoked somatic responses. The features of the cardiac response, together with the results of frequency-domain analyses of heart period variability, suggest that this acceleratory response was consistent with the evocation of an aversive or a defensive reaction characterized by sympathetic activation. This pattern of cardiac response appeared early in ontogeny (within 48 hr postnatally) and was not manifest in orangutans. Taken together, the results suggest the existence of specialized perceptual processing mechanisms for vocal stimuli in the chimpanzee. Further examination of these mechanisms may contribute to our understanding of central perceptual processes and the evolution of vocal communication

    Scale space consistency of piecewise constant least squares estimators -- another look at the regressogram

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    We study the asymptotic behavior of piecewise constant least squares regression estimates, when the number of partitions of the estimate is penalized. We show that the estimator is consistent in the relevant metric if the signal is in L2([0,1])L^2([0,1]), the space of c\`{a}dl\`{a}g functions equipped with the Skorokhod metric or C([0,1])C([0,1]) equipped with the supremum metric. Moreover, we consider the family of estimates under a varying smoothing parameter, also called scale space. We prove convergence of the empirical scale space towards its deterministic target.Comment: Published at http://dx.doi.org/10.1214/074921707000000274 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

    Size Matters: Impact of Item Size and Quantity on Array Choice by Chimpanzees (Pan troglodytes)

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    The authors previously reported that chimpanzees (Pan troglodytes) showed a striking bias to select the larger of 2 candy arrays, despite a reversed reward contingency in which the animals received the smaller, nonselected array as a reward, except when Arabic numerals were used as stimuli. A perceptual or incentive-based interference occurred that was overcome by symbolic stimuli. The authors of the present study examined the impact of element size in choice arrays, using 1 to 5 large and small candies. Five test-sophisticated chimpanzees selected an array from the 2 presented during each trial. Their responses were not optimal, as animals generally selected arrays with larger total mass; thus, they received the smaller remaining array as a reward. When choice stimuli differed in size and quantity, element size was more heavily weighted, although choices reflected total candy mass. These results replicate previous findings showing chimpanzees\u27 difficulties with quantity judgments under reverse reward contingencies and also show that individual item size exerts a more powerful interference effect

    Vocal Perception: Brain Event-Related Potentials in a Chimpanzee

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    We describe the first brain event-related potential (ERP) study of cognitive processes in the chimpanzee. In an extension of our studies on the ontogeny of vocal perception, ERP measures were obtained during the presentation of simple nonsignal stimuli as well as conspecific and human vocalizations. We initially confirmed findings from humans and monkeys of the appearance of a long-latency positivity in the ERP waveform to a rare stimulus in an oddball paradigm. This ERP component is reminiscent of the P3a reported in humans under similar (passive) experimental conditions. We further demonstrated that both conspecific and human vocal stimuli having affective significance also enhanced late positive components of the ERP. These late positive components displayed a predominant fronto-central distribution, with a maxima at Cz. Additionally, responses to adaptively significant vocal stimuli showed a right hemisphere laterality, whereas no significant laterality was observed with the rare stimulus in the oddball paradigm. Results document the feasibility of ERP measures in chimpanzees and their potential utility in the study of the ontogeny and phylogeny of vocal perception

    Virtues education in medical school: the foundation for professional formation

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    Background: Studies have shown that medical students have high rates of burnout accompanied by a loss of empathy as they progress through their training. This article describes a course for medical students at The University of Queensland-Ochsner Clinical School in New Orleans, LA, that focuses on the development of virtues and character strengths necessary in the practice of medicine. Staff of the Ochsner Clinical School and of the Institute of Medicine, Education, and Spirituality at Ochsner, a research and consulting group of Ochsner Health System, developed the course. It is a curricular innovation designed to explicitly teach virtues and their associated prosocial behaviors as a means of promoting professional formation among medical students. Virtues are core to the development of prosocial behaviors that are essential for appropriate professional formation. Methods: Fourth-year medical students receive instruction in the virtues as part of the required Medicine in Society (MIS) course. The virtues instruction consists of five 3-hour sessions during orientation week of the MIS course and a wrapup session at the end of the 8-week rotation. Six virtues—courage, wisdom, temperance, humanity, transcendence, and justice—are taught in a clinical context, using personal narratives, experiential exercises, contemplative practices, and reflective practices. Results: As of July 2015, 30 medical students had completed and evaluated the virtues course. Ninety-seven percent of students felt the course was well structured. After completing the course, 100% of students felt they understood and could explain the character strengths that improve physician engagement and patient care, 100% of students reported understanding the importance of virtues in the practice of medicine, and 83% felt the course provided a guide to help them deal with the complexities of medical practice. Ninety-three percent of students stated they would use the character strengths for their own well-being, and 90% said they would change their approach to the practice of medicine as a result of this course. Overall, 92% of students rated the course as outstanding or good. Conclusion: We developed a course to teach virtues and their associated prosocial behaviors that are important for the practice of medicine. After completing the course, students self-reported improved understanding of the virtues and their importance to the practice of medicine. We plan further studies to determine if participation in the course leads to less burnout and improved resilience

    Identifizierung VHL-assoziierter Veränderungen im klarzelligen Nierenzellkarzinom: Anwendung von kombinierten Genom- und Expressionsanalysen

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    Zusammenfassung: Das sporadische Nierenzellkarzinom (NZK) ist ein heterogener solider Tumor, der traditionell basierend auf morphologischen Kriterien in weitere Subtypen unterteilt wird. In den letzten Jahren konnten unter Anwendung molekularer Hochdurchsatzanalysen genetische, transkriptionelle und translationale Alterationen identifiziert werden. Diese Marker eignen sich zum einen für die molekulare Klassifizierung des NZK und haben zum anderen prognostische Wertigkeit. Die isolierte Betrachtung genetischer, transkriptioneller und translationaler Veränderungen verhindert jedoch ein tieferes Verständnis für die komplexen Vorgänge der Karzinogenese. Wir fassen hier aktuelle Forschungsergebnisse zur molekularen Charakterisierung des NZK zusammen und stellen ein systembiologisches Konzept zur Identifizierung neuer Tumormarker vor. Diese könnten zukünftig Einsatz in der Diagnostik und Therapie des sporadischen NZK finde
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