1,022 research outputs found
Convergent results in eyeblink conditioning and contingency learning in humans: addition of a common cue does not affect feature-negative discriminations
No full textPrevious human discrimination learning experiments with eyeblink conditioning showed that an increase in the similarity between the to-be-discriminated stimuli had no effect on the rate of learning. This result was at variance with data from other experiments which had used different paradigms and different stimulus materials. We therefore compared human discrimination learning in eyeblink conditioning and contingency learning using carefully matched procedures. Participants learned two feature-negative discriminations, A+/AB? and CD+/CDE?. Convergent results were obtained in both paradigms. Adding a common cue did not affect response differentiation, i.e. the A+/AB? discrimination and the CD+/CDE? discriminations were equivalent. These results support the notion that learning in both paradigms is based on the same principles. However, the overall pattern of results cannot be easily accommodated within associative learning theories based on the Rescorla–Wagner Model or on Pearce's Configural Model. The application of these models to current and previous data is discussed.<br/
Supplemental_Fig_S2 – Supplemental material for How competitive is cue competition?
No full textSupplemental material, Supplemental_Fig_S2 for How competitive is cue competition? by Julian Packheiser, Roland Pusch, Clara C Stein, Onur Güntürkün, Harald Lachnit and Metin Uengoer in Quarterly Journal of Experimental Psychology</p
Supplemental_Fig_S1 – Supplemental material for How competitive is cue competition?
No full textSupplemental material, Supplemental_Fig_S1 for How competitive is cue competition? by Julian Packheiser, Roland Pusch, Clara C Stein, Onur Güntürkün, Harald Lachnit and Metin Uengoer in Quarterly Journal of Experimental Psychology</p
Supplemental_Fig_S3 – Supplemental material for How competitive is cue competition?
No full textSupplemental material, Supplemental_Fig_S3 for How competitive is cue competition? by Julian Packheiser, Roland Pusch, Clara C Stein, Onur Güntürkün, Harald Lachnit and Metin Uengoer in Quarterly Journal of Experimental Psychology</p
Supplemental_Fig_S5 – Supplemental material for How competitive is cue competition?
No full textSupplemental material, Supplemental_Fig_S5 for How competitive is cue competition? by Julian Packheiser, Roland Pusch, Clara C Stein, Onur Güntürkün, Harald Lachnit and Metin Uengoer in Quarterly Journal of Experimental Psychology</p
Supplemental_Fig_S4 – Supplemental material for How competitive is cue competition?
No full textSupplemental material, Supplemental_Fig_S4 for How competitive is cue competition? by Julian Packheiser, Roland Pusch, Clara C Stein, Onur Güntürkün, Harald Lachnit and Metin Uengoer in Quarterly Journal of Experimental Psychology</p
Reizrepräsentation und -verarbeitung im Assoziativen Lernen beim Menschen: Eine Evaluation aktueller elementarer und konfiguraler Assoziativer Lerntheorien
No full textTheories of associative learning describe learning about the relationship between two events, e.g. the eating of an apple and subsequent stomach ache. One important classification of these models is based on the stimulus representation they suppose. Whereas elemental models assume that the representations of a stimulus compound consist of representations of its components establishing associations, configural models propose that stimulus compounds are represented and associated as a whole. However, as the empirical results have not consistently favoured one class of models, it was suggested that humans and animals can switch between both modes of stimulus representation. Alternatively, modern theories as the elemental model of Wagner (2003) and Harris (2006) or the extended configural model of Pearce (Kinder & Lachnit, 2003) postulate flexibility within either elemental or configural principles and question the existence of a second, fundamentally different mode of stimulus representation. In order to evaluate these two hypotheses, we contrasted the predictions of the elemental and configural models. Firstly, a user-friendly environment for computer simulation of the models was written. Then, contradicting predictions were tested in two series of human learning experiments. Furthermore, it was investigated whether manipulations of the experimental setting would influence stimulus processing and on which mechanism these effects are based.
The results demonstrate that models that comprise configural principles are not made superfluous by modern elemental models. Instead, the extended version of Pearce’s configural model was able to account for all behaviour observed both during learning of two feature-negative discriminations as well as in generalisation tests after learning. Together with the “elemental” results of other studies, this corroborates the position that there are two modes of stimulus processing during associative learning. Further tests and experiments, however, are necessary concerning factors that influence which mode is chosen in a learning situation. Manipulations of the stimulus material (perceptual grouping by motion; spatial arrangement) as well as manipulations of the experimental procedure (learning paradigm; time pressure during stimulus presentation; causal nature of the cover story) had no effects. This indicates that more controlled research is needed investigating not only the factors but also the circumstances controlling these factors’ relevance. Furthermore, additional theoretical analyses revealed that the observed advantage of the configural model is not based on the configural representation itself but on a normalisation of the representation’s activation. Therefore, elemental models incorporating this mechanism could compensate their present shortcoming.Assoziative Lerntheorien beschreiben das Erlernen von Zusammenhängen zwischen Ereignissen, zum Beispiel zwischen dem Essen eines Apfels und darauf folgenden Bauchschmerzen. Lange Zeit wurden dabei zwei Klassen von Modellen gegenübergestellt. Während in elementaren Theorien Reizkonfigurationen in ihre Komponenten zerlegt werden und diese dann jeweils Assoziationen eingehen, werden in konfiguralen Modellen Reizkonfigurationen als Ganzes miteinander verknüpft. Aufgrund der widersprüchlichen empirischen Befundlage stellt sich jedoch die Frage, ob Menschen und Tiere nicht in der Lage sind beide Arten der Reizrepräsentation anzuwenden. Demgegenüber postulieren moderne Theorien wie die elementaren Modelle von Wagner (2003) und Harris (2006) oder das erweiterte konfigurale Modell von Pearce (Kinder & Lachnit, 2003) Flexibilität innerhalb elementarer bzw. konfiguraler Grundprinzipien und stellen die Existenz einer zweiten grundsätzlich unterschiedlichen Form der Reizrepräsentation in Frage. Um diese beiden Ansätze zu vergleichen, wurden Vorhersagen der elementaren und konfiguralen Modelle gegenübergestellt. Hierzu wurde zunächst ein benutzerfreundliches Computerprogramm zur Simulation der Modelle geschrieben. Daraufhin wurden in zwei Serien von Lernexperimenten mit Menschen sowohl sich widersprechenden Vorhersagen empirisch getestet als auch Faktoren des experimentellen Settings manipuliert, um so die Art der Reizverarbeitung zu beeinflussen und ihre Wirkmechanismen zu untersuchen.
Insgesamt machen die Ergebnisse aller Experimente deutlich, dass auch moderne elementare Modelle konfigurale Modelle nicht ersetzen können. Stattdessen stimmte das beobachtete Verhalten sowohl aus der Lernphase zweier Feature-Negative Diskriminationen als auch die Generalisationsdekremente nach erfolgreichem Diskriminationstraining nur mit der erweiterten Form des konfiguralen Modells von Pearce überein. Im Kontext bisheriger Befunde spricht dies für die Existenz zweier Arten der Reizrepräsentation. Jedoch konnten keine eindeutigen Einflussfaktoren nachgewiesen werden, die bestimmen, welche Art der Repräsentation Menschen in einer Situation wählen. Weder Manipulationen des Reizmaterials (perzeptuelle Gruppierung durch Bewegung, räumliche Anordnung der Reize) noch der experimentellen Durchführung (Lernparadigma, Zeitdruck während der Reizdarbietung, kausale Charakter des Szenarios) zeigten Effekte. Stattdessen wurde deutlich, dass zukünftige Forschung sich auf die Umstände, die die Bedeutung der untersuchten Faktoren kontrollieren, konzentrieren muss. Abschließende theoretische Analysen verdeutlichen darüber hinaus, dass die beobachtete Überlegenheit des konfiguralen Modells nicht auf der konfiguralen Repräsentation an sich beruht, sondern auf eine damit einhergehende Normalisierung der Aktivierungsstärke zurückgeht. Daraus folgernd sollten elementare Modelle, die diesen Mechanismus beinhalten, diesen Vorteil des konfiguralen Modells ausgleichen können
Applied algebra and number theory: essays in honour of Harald Niederreiter on the occasion of his 70th birthday
No full text"Harald Niederreiter's pioneering research in the field of applied algebra and number theory has led to important and substantial breakthroughs in many areas, including finite fields and their application areas as coding theory and cryptography as well as uniform distribution and quasi-Monte Carlo methods. He is author of more than 350 research papers and 10 books"-
To be or not to be... disabled. Primingeffekte auf Einschätzungen von Wärme und Kompetenz
No full textEyssel FA, Zebrowitz LA. To be or not to be.. disabled. Primingeffekte auf Einschätzungen von Wärme und Kompetenz. In: Khader P, Jost K, Lachnit H, Rösler F, eds. Beiträge zur 50. Tagung experimentell arbeitender Psychologen (TEAP). Lengerich: Pabst; 2008
Reduced summation with common features in causal judgement
No full textIn three experiments human participants received training in a causal judgement task. After learning which patterns were associated with an outcome, participants rated the likelihood of the outcome in the presence of a novel combination of the patterns. The first two experiments used two conditions in which two visual patterns were associated with the outcome. In one condition these patterns shared a common feature. The third experiment only used the common feature condition. According to an elemental theory (Rescorla & Wagner, 1972) the response to the novel test pattern should have exceeded that made to the individual training patterns, a summation effect, and this effect should have been reduced by the addition of a common feature. Summation was observed but since the common feature condition abolished, rather than merely reduced summation the results were not consistent with the Rescorla-Wagner Model nor with a configural alternative (Pearce, 1994). Instead, it is necessary to consider models which allow the possibility of both elemental and configural strategies in causal learning. The Replaced Elements Model (Wagner, 2003) is a development of the Rescorla-Wagner Model which can best predict the patterns of summation and summation failure in these experiments
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