Humboldt-Universität zu Berlin - Lebenswissen­schaftliche Fakultät - Institut für Psychologie

Research projects

A complete list of research projects can be found at Abdel Rahman Lab

 


Knowledge-augmented face perception

 

Face perception and categorization is fundamental to social interactions. In humans, input from facial features is integrated with top-down influences from other cognitive domains, such as expectations, memories and contextual knowledge. In contrast to human perception, automatic systems of face processing are typically based purely on bottom-up information without considering factors as prior knowledge. The aim of this project is therefore to bridge the gap between human and synthetic face processing by integrating top-down components typical for human perception into synthetic systems. The results of experiments involving human subjects in combination with video recordings will be used in deep learning training procedures aiming at the development of computational models.

 

  • Since 2019
  • PIs: Prof. Dr. Rasha Abdel Rahman, Prof. Dr. Olaf Hellwich
  • Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2002/1 “Science of Intelligence”

 


Multimodal Interaction and Communication

 

The overall goal of this project is to create a robot that can represent and integrate information from different sources and modalities for successful, task-oriented interactions with other agents. To fully understand the mechanisms of social interaction and communication in humans and to replicate this complex human skill in technological artifacts, we must provide effective means of knowledge transfer between agents. The first step of this project is therefore to describe core components and determinants of communicative behaviour including joint attention, partner co-representation, information processing from different modalities and the role of motivation and personal relevance. We will compare these functions in human-human, human-robot, and robot-robot interactions to identify commonalities and differences. This comparison will also consider the role of different presumed partner attributes (e.g., a robot described as “social” or “intelligent”).  We will conduct behavioural, electrophysiological, and fMRI experiments to describe the microstructure of communicative behaviour.
 The second step of the project is to create predictive models for multimodal communication that can account for these psychological findings in humans. Both the prerequisites and factors acting as priors will be identified, and suitable computational models will be developed that can represent multimodal sensory features in an abstract but biologically inspired way (suitable for extracting principles of intelligence).
Throughout the project we will focus on the processing of complex multimodal information, a central characteristic of social interactions, that have nevertheless thus far been investigated mostly within modalities. We assume that multimodal information, e.g. from auditory (speech) and visual (face, eye gaze) or tactile (touch) information, will augment the partner co-representation and will therefore improve communicative behaviour.

 

  • Since 2019
  • PIs: Prof. Dr. Rasha Abdel Rahman, Prof. Dr. Verena Hafner, Dr. Anna Kuhlen, and Prof. Dr. John-Dylan Haynes
  • Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC 2002/1 “Science of Intelligence”

 


Effects of age and language proficiency on the processing of morphologically complex words

 

The project examines the lexical representation and processing of compound nouns (e.g., goldfish) in speech production. The representational structure of compounds at the lemma level is investigated in detail. In addition, the underlying processes in the lexicalization of new (unfamiliar) compounds (e.g., *piano fish) are examined. Both, healthy adult speakers across different age groups and individuals with aphasia are tested.

In picture-naming tasks with compounds as targets, both syntactic (grammatical gender) and semantic effects are assessed. Different experimental paradigms are used, and behavioral and electrophysiological measures (EEG) are analyzed. In one module, effects of gender-marked determiner primes on noun-noun compound production are tested. In another module, semantic effects on the production of compounds and simple nouns (constituents of compounds) are tested in the continuous (cumulative semantic) picture-naming paradigm. Furthermore, the impact of non-verbal cognitive functions (attentional control and inhibition) is examined.

The following research questions are tested: 1) How are compounds lexically stored and how are they accessed during speech production across the life span? 2) How does the lexical acquisition of new (unfamiliar) compounds (e.g., *piano fish) work? 3) How do semantic and lexical functions affect compound production in healthy older and aphasic speakers? 4) What is the role of non-verbal attentional control processes in speech production?

In summary, the project aims at a better understanding of the lexical representation and processing of morphologically complex nouns in speaking. In particular, effects of ageing, language proficiency, and of non-verbal cognitive control are examined

 

  • Since 2019
  • PI: Dr. Antje Lorenz
  • Funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation, LO 2182/1-1 and 1-2)

 


Language production in shared task settings

 

Typically, people speak in the context of social interaction. Yet, surprisingly little is known about how the neuro-cognitive processes of language production are shaped by social interaction. Drawing upon a well-established effect in language production we investigate the degree of semantic interference experienced when naming a sequence of pictures together with a task partner. In single subject settings, naming latencies increase with each new picture of a given semantic category, so-called cumulative semantic interference (e.g., Howard et al., 2006). Recently, it has been demonstrated that naming latencies not only increase in response to speakers’ own prior naming of semantically related pictures, but also in response to their task partner naming pictures (Hoedemaker, Ernst, Meyer, & Belke, 2017; Kuhlen & Abdel Rahman, 2017). This suggests that task partners represent each other’s actions and engage in lexicalization on behalf of their partner. Based on these findings we want to specify (1) the mechanism behind partner-elicited semantic interference, (2) the extent to which lexical access on behalf of the partner reflects the specific nature of the partner’s task (and not just the own task), and (3) whether partner-elicited lexical access depends on characteristics of the task partner or the task setting. Finally, we want to understand (4) how our findings within the framework of joint picture naming scale up to conversation. We expect insights into these questions through a series of experiments based on behavioral observations of latencies during joint picture naming and electrophysiological, event-related recordings. The results from the here proposed project will contribute to a better understanding of language production during social interaction as well as deepen our understanding of how flexibly the semantic system adapts to social context.

 

  • since 2019
  • PIs: Dr. Anna Kuhlen and  Prof. Dr. Rasha Abdel Rahman
  • project funding by the German Research Association (DFG)

 


Insight: Neuroscientific investigations of knowledge effects on visual perception and awareness

 

According to classic and current models visual perception can be viewed as encapsulated in the sense that it is not modulated by cognitive factors such as expectations or prior knowledge. Yet, evidence is cumulating that even verbally transmitted knowledge shapes perception, as has been demonstrated in the first phase of the current project. The perception of faces and objects can be modulated by knowledge, and this can have considerable consequences not only on how we perceive and evaluate our environment, but also on our behaviour and social interactions. To date, not much is known about the precise mechanisms of knowledge effects on perception, and even less is known about influences of knowledge on visual awareness. The main goals of the second phase are therefore to determine the precise mechanisms that underlie knowledge effects on perception and to investigate the potential influences of knowledge on visual awareness. Part 1 investigates with event-related brain potentials (1) the influence of visually derived information (e.g., about emotional states, attractiveness or personality impressions as trustworthiness) on effects of socially relevant person related information, (2) effects of gossip that is verbally marked as uncertain on face perception and moral judgments, and (3) whether the observed effects of abstract, verbally transmitted information generalize to knowledge that is based on direct communicative experience. Part 2 investigates visual awareness and how it is modulated by (1) by socially relevant knowledge that is long established memory and potentially embedded in the visual representations of faces, (2) by perceptual-semantic expertise, and (3) by the congruency of knowledge and the visual properties of faces and objects. The planned research should contribute to a better understanding of the basic mechanisms and limits of knowledge induced influences on visual perception and visual awareness.

 

  • since 2017
  • PI  Prof. Dr. Rasha Abdel Rahman
  • project funding by the German Research Association (DFG)

 


„Through the lens of affective knowledge: A cross-national study on the perception of facial expressions“

 

  • since November 2013
  • PIs Berlin: Prof. Dr. Rasha Abdel Rahman, Dr. Franziska Süß
  • PIs Jerusalem: Dr. Hillel Aviezer, Dr. Ran Hassin
  • project funding by the Hebrew University – Humboldt-Universität Cooperation Call 2013

 

Human faces and the information derived from emotional facial expressions play a critical role in human social interactions. According to most theoretical accounts expressions are viewed as invariant manifestations of specific emotional states (e.g., anger, happiness, disgust etc.). Accordingly, extensive research has been dedicated to identifying the general neuro-cognitive basis of invariant expression perception, and very little is known about flexible and variable aspects.

The proposed research will investigate such variable aspects by testing whether expression perception can be modulated by the emotional valence of our biographical knowledge about a person. Specifically, we ask whether positive or negative biographical information (e.g., perceiving the face of a person known or presumed to be a murderer or a

philanthropist) shapes how we see his or her facial expression. To gain insight into the temporal dynamics of the affective knowledge effects, and to localize these at perceptual or post-perceptual evaluative processing stages, the electroencephalogram will be co-registered in Berlin and eye movements will be recorded in Jerusalem.

Effects of visually opaque affective information would suggest that facial expressions cannot be viewed independently of our knowledge about the person we see, may this knowledge be correct or false, biased or unbiased. This would have implications not only for expression perception but also for social interactions.

 

The project is conducted in cooperation with the Hebrew-University of Jerusalem, Israel.

 


 

Einsicht: Neurowissenschaftliche Untersuchungen des Einflusses von Wissen auf Wahrnehmung und Bewusstsein

 

  • seit Mai 2012
  • Leitung: Prof. Dr. Rasha Abdel Rahman
  • Projektmitglieder: Milena Rabovsky
  • Förderung durch die Deutsche Forschungsgemeinschaft (DFG)

 

Traditionellen Modellannahmen zufolge findet der Zugriff auf semantische Wissensinhalte zu einem vergleichsweise späten Zeitpunkt nach der abgeschlossenen perzeptuellen Analyse statt und hat auf diese keinen Einfluss. Aktuelle Befunde weisen jedoch darauf hin, dass die in unserem Gedächtnis gespeicherten Wissensstrukturen einen sogar beträchtlichen Einfluss auf elementare perzeptuelle Leistungen haben können. Je nach Art des Wissens und der betroffenen bewussten oder unbewussten perzeptuellen Prozesse kann dies erhebliche Konsequenzen für die Wahrnehmung und Beurteilung unserer Umwelt, aber auch für unser Verhalten und unsere sozialen Interaktionen haben. Die Erforschung dieses bislang wenig untersuchten Wechselspiels zwischen Wissen, Wahrnehmung und visuellem Bewusstsein steht im Zentrum dieses Projekts. Mit neurowissenschaftlichen Methoden sollen die Einflüsse semantisch-funktionalen, affektiven und sprachlichen Wissens untersucht und verglichen werden. Insgesamt könnte dieses Projekt interessante Informationen darüber liefern, wie Wissen, aber auch vermeintliches Wissen und Vorurteile die (bewusste) Wahrnehmung von Personen und Gegenständen in unserer Umgebung prägt.
 


 

Dynamik und Flexibilität des Sprachproduktionssystems

 

  • seit November 2008
  • Leitung: Prof. Dr. Rasha Abdel Rahman
  • Projektmitglieder: Sebastian Rose
  • Förderung durch die Deutsche Forschungsgemeinschaft (DFG)

 

Der Zugriff auf das mentale Lexikon im Verlauf der Sprechplanung wurde lange Zeit nahezu unumstritten als kompetitiver Prozess betrachtet, während dessen die Selektion einer geplanten Zieläußerung mit semantischen Alternativen konkurriert. Jüngere Befunde, insbesondere berichtete Ausnahmen semantischer Interferenzeffekte, haben jedoch eine theoretische Kontroverse hinsichtlich der Lokalisation dieser Effekte und der Existenz lexikalischer Konkurrenzmechanismen ausgelöst, zu deren Klärung das Projekt beitragen soll. Dabei wird lexikalische Kohortenaktivierung als ein neuer Ansatz zur Erklärung der divergenten Befunde vorgeschlagen und als maßgebliche Determinante für das Auftreten von Interferenzeffekten getestet. In einer Serie von Experimenten wird untersucht, inwiefern kontextuelle Modulationen eine Aktivierung lexikalischer Kohorten bewirken und somit semantische Interferenzeffekte induzieren können. Ein zentrales Ziel dieser Experimente ist die Untersuchung der Flexibilität und situationsspezifischen Formbarkeit der Mikrostruktur der Sprechplanung durch Kohortenaktivierung.

 



Wie Wunder wirken: minimal kontraintuitive Konzepte im Kontext von Emotion und Sprachstil

 

  • seit Oktober 2009
  • Leitung: Prof. Dr. Rasha Abdel Rahman, Prof. Dr. Werner Sommer, Prof. Dr. Arthur Jacobs, Prof. Dr. Oliver Lubrich
  • Projektmitglieder: Sabrina Aristei, Thomas Nehrlich, Christine Knoop
  • Förderung durch den Exzellenzcluster 302 "Languages of Emotion", Freie Universität Berlin


Unser „semantisches“ Langzeitwissen, wie wir es im Laufe des Lebens erwerben, enthält Konzepte, die häufig in Form klar strukturierter Taxonomien, Kategorien oder Assoziationen organisiert sind. Interessanterweise sind viele kulturell erfolgreiche Konzepte, wie sie beispielsweise in Märchen oder Mythen enthalten sind, gerade durch ihre Eigenschaft gekennzeichnet, diese scheinbar klaren Strukturen des semantischen Systems zu verletzen, beispielsweise Zombies (agierende Tote), Geister (körperlose Agenten), Substanzverwandlungen oder sprechende Tiere. Diese so genannten minimal kontraintuitiven Elemente (MCIs) sind möglicherweise mitverantwortlich für den Erfolg derartiger Wissensinhalte. Kulturell besonders erfolgreiche MCIs scheinen weiterhin durch einen ausgeprägten emotionalen Kontext gekennzeichnet zu sein und über einen spezifischen, in der Regel „gehobenen“ Sprachduktus vermittelt zu werden. Das Projekt untersucht die neurokognitiven Wirkmechanismen des Erfolgs von MCIs mit Verhaltensstudien in Kombination mit neurowissenschaftlichen Verfahren (EEG, fMRI) und Modellierungen.

 



Semantische Expertise in der Gesichtererkennung und Sprachproduktion (abgeschlossen)

 

  • seit Dezember 2004
  • Leitung: Dr. R. Abdel Rahman
  • Förderung durch die Deutsche Forschungsgemeinschaft (DFG)

 

Zu den praktisch bedeutsamsten Funktionen des menschlichen informations-verarbeitenden Systems gehören die Fähigkeiten des Erkennens bekannter Gesichter und Objekte und der Sprachproduktion, wobei in beiden Bereichen der Abruf semantischer Informationen eine elementare Verarbeitungskomponente darstellt. In diesem Projekt werden Gesichtererkennung bzw. Benennung und Sprachproduktion unter dem Aspekt der semantischen Expertise untersucht. Im speziellen wird der Frage nachgegangen, ob und in welcher Ausprägung ein zunehmendes Maß im Langzeitgedächtnis gespeicherten Wissens mit funktionalen Veränderungen der Identifikations- und Benennungsleistung einhergeht und ob neuronale Korrelate semantischer Expertise identifiziert werden können.