TY - JOUR A1 - Crutzen, Rik A1 - Göritz, Anja S. T1 - Does social desirability compromise self-reports of physical activity in web-based research? JF - International Journal of Behavioral Nutrition and Physical Activity N2 - Background: This study investigated the relation between social desirability and self-reported physical activity in web-based research. Findings: A longitudinal study (N = 5,495, 54% women) was conducted on a representative sample of the Dutch population using the Marlowe-Crowne Scale as social desirability measure and the short form of the International Physical Activity Questionnaire. Social desirability was not associated with self-reported physical activity (in MET-minutes/week), nor with its sub-behaviors (i.e., walking, moderate-intensity activity, vigorous-intensity activity, and sedentary behavior). Socio-demographics (i.e., age, sex, income, and education) did not moderate the effect of social desirability on self-reported physical activity and its sub-behaviors. Conclusions: This study does not throw doubt on the usefulness of the Internet as a medium to collect self-reports on physical activity. KW - Question format KW - Internet KW - Physical Activity KW - Sedentary Behavior KW - Social Desirability KW - International Physical Activity Questionnaire KW - Total Physical Activity Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-135156 VL - 8 IS - 31 ER - TY - JOUR A1 - Bilalic, Merim A1 - Kiesel, Andrea A1 - Pohl, Carsten A1 - Erb, Michael A1 - Grodd, Wolfgang T1 - It Takes Two–Skilled Recognition of Objects Engages Lateral Areas in Both Hemispheres JF - PLoS ONE N2 - Our object recognition abilities, a direct product of our experience with objects, are fine-tuned to perfection. Left temporal and lateral areas along the dorsal, action related stream, as well as left infero-temporal areas along the ventral, object related stream are engaged in object recognition. Here we show that expertise modulates the activity of dorsal areas in the recognition of man-made objects with clearly specified functions. Expert chess players were faster than chess novices in identifying chess objects and their functional relations. Experts’ advantage was domain-specific as there were no differences between groups in a control task featuring geometrical shapes. The pattern of eye movements supported the notion that experts’ extensive knowledge about domain objects and their functions enabled superior recognition even when experts were not directly fixating the objects of interest. Functional magnetic resonance imaging (fMRI) related exclusively the areas along the dorsal stream to chess specific object recognition. Besides the commonly involved left temporal and parietal lateral brain areas, we found that only in experts homologous areas on the right hemisphere were also engaged in chess specific object recognition. Based on these results, we discuss whether skilled object recognition does not only involve a more efficient version of the processes found in non-skilled recognition, but also qualitatively different cognitive processes which engage additional brain areas KW - Expert chess players KW - Anterior inferotemporal cortex KW - Deliberate practice KW - Neural basis KW - Function knowledge KW - Parietal cortex KW - Macaque monkey KW - Temporal areas KW - Memory KW - Task Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-176935 VL - 6 IS - 1 ER - TY - THES A1 - Anderson, Christina T1 - Idiosyncratic Facial Movement in Face Perception and Recognition T1 - Idiosynkratische Gesichtsbewegung in Gesichterwahrnehmung und -erkennung N2 - It has been proposed that different features of a face provide a source of information for separate perceptual and cognitive processes. Properties of a face that remain rather stable over time, so called invariant facial features, yield information about a face’s identity, and changeable aspects of faces transmit information underlying social communication such as emotional expressions and speech movements. While processing of these different face properties was initially claimed to be independent, a growing body of evidence suggests that these sources of information can interact when people recognize faces with whom they are familiar. This is the case because the way a face moves can contain patterns that are characteristic for that specific person, so called idiosyncratic movements. As a face becomes familiar these idiosyncratic movements are learned and hence also provide information serving face identification. While an abundance of experiments has addressed the independence of invariant and variable facial features in face recognition, little is known about the exact nature of the impact idiosyncratic facial movements have on face recognition. Gaining knowledge about the way facial motion contributes to face recognition is, however, important for a deeper understanding of the way the brain processes and recognizes faces. In the following dissertation three experiments are reported that investigate the impact familiarity of changeable facial features has on processes of face recognition. Temporal aspects of the processing of familiar idiosyncratic facial motion were addressed in the first experiment via EEG by investigating the influence familiar facial movement exerts on event-related potentials associated to face processing and face recognition. After being familiarized with a face and its idiosyncratic movement, participants viewed familiar or unfamiliar faces with familiar or unfamiliar facial movement while their brain potentials were recorded. Results showed that familiarity of facial motion influenced later event-related potentials linked to memory processes involved in face recognition. The second experiment used fMRI to investigate the brain areas involved in processing familiar facial movement. Participants’ BOLD-signal was registered while they viewed familiar and unfamiliar faces with familiar or unfamiliar idiosyncratic movement. It was found that activity of brain regions, such as the fusiform gyrus, that underlie the processing of face identity, was modulated by familiar facial movement. Together these two experiments provide valuable information about the nature of the involvement of idiosyncratic facial movement in face recognition and have important implications for cognitive and neural models of face perception and recognition. The third experiment addressed the question whether idiosyncratic facial movement could increase individuation in perceiving faces from a different ethnic group and hence reduce impaired recognition of these other-race faces compared to own-race faces, a phenomenon named the own-race bias. European participants viewed European and African faces that were each animated with an idiosyncratic smile while their attention was either directed to the form or the motion of the face. Subsequently recognition memory for these faces was tested. Results showed that the own-race bias was equally present in both attention conditions indicating that idiosyncratic facial movement was not able to reduce or diminish the own-race bias. In combination the here presented experiments provide further insight into the involvement of idiosyncratic facial motion in face recognition. It is necessary to consider the dynamic component of faces when investigating face recognition because static facial images are not able to provide the full range of information that leads to recognition of a face. In order to reflect the full process of face recognition, cognitive and neural models of face perception and recognition need to integrate dynamic facial features as a source of information which contributes to the recognition of a face. N2 - Klassische Gesichtsverarbeitungsmodelle postulieren die Unabhängigkeit der Wahrnehmung von unveränderlichen Gesichtsmerkmalen und zeitlich veränderlichen, dynamischen Aspekten eines Gesichts. Während zeitlich stabile Charakteristika die Basis für die Identifikation eines Gesichts bilden, wird Information über dynamische Gesichtsveränderungen im Rahmen sozialer Kommunikation herangezogen z.B. um emotionale Ausdrücke und Intentionen zu erkennen. Während diese Modelle allgemein starke empirische Fundierung aufweisen, mehren sich im Falle von bekannten Gesichtern die Hinweise, dass idiosynkratische Gesichtsbewegungen zur Identifikation einer Person beitragen können. Im Folgenden werden drei Experimente vorgestellt, die sich mit dem Einfluss bekannter Gesichtsbewegung auf die Gesichtsidentifikation befassen. Im ersten Experiment wurde mittels EEG der Einfluss bekannter Bewegung auf evozierte Potentiale der Gesichtsverarbeitung und –erkennung untersucht. Es zeigt sich, dass die Bekanntheit der Gesichtsbewegung Potentiale der Gesichtserkennung beeinflusst. Im zweiten Experiment wurden durch fMRI die Gehirnareale untersucht, die an der Wahrnehmung bekannter Gesichtsbewegung beteiligt sind. Aktivität in Gehirnarealen, die der Verarbeitung von Gesichtsidentität zu Grunde liegen, wie z.B. der fusiforme Gyrus, wurde durch die Bekanntheit der Bewegung des Gesichts moduliert. Zusammen liefern diese beiden Experimente wertvolle Information über die Beteiligung idiosynkratischer Gesichtsdynamik bei der Gesichtsidentifikation. Das dritte Experiment beschäftigte sich mit der Fragestellung, ob eine idiosynkratische Gesichtsbewegung die Individualisierung eines Gesichts im interkulturellen Kontext erhöhen kann und somit den own-race bias, d.h. eine schwächere Wiedererkennensleistung für Gesichter einer anderen ethnischen Herkunft, verglichen mit Gesichtern der eigenen Ethnie, verringern kann. Die Ergebnisse dieses Experiments zeigen zwar eine geringere Wiedererkennensleistung europäischer Versuchspersonen gegenüber Afrikanischen Gesichtern, verglichen mit der Wiedererkennensleistung für Europäische Gesichter, die Salienz der idiosynkratischen Gesichtsbewegung zeigte jedoch keinen Einfluss auf die Wiedererkennensleistung. Die Ergebnisse werden im Kontext der Ergebnisse der EEG Studie diskutiert. Zusammenfassend bieten die hier vorgestellten Daten weiteres Verständnis über das Zusammenspiel von stabilen und veränderlichen Gesichtscharakteristika bei der Gesichtsidentifikation. Es ist wichtig, die dynamische Komponente von Gesichtern zu berücksichtigen, wenn man ein ganzheitliches Bild über die Prozesse, die der Gesichtswahrnehmung und –erkennung zu Grunde liegen, gestalten will. KW - Gesicht KW - Wahrnehmung KW - Gesichtererkennung KW - Gesichtsdynamik KW - fMRT KW - Sehrinde KW - Avatar KW - face recognition KW - dynamic faces KW - face processing Y1 - 2011 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-70355 ER -