Fenna Poletiek, PhD

Expertise:
  • Grammar induction, statistical learning, hypothesis testing, decision making


Telephone number: +31 (0)71 527 3641
E-Mail: poletiek@fsw.leidenuniv.nl
Faculty / Department: Faculteit der Sociale Wetenschappen, Instituut Psychologie, Cognitieve Psychologie
Office Address: Pieter de la Court gebouw
Wassenaarseweg 52
2333 AK Leiden
Room number 2B24
Personal Homepage: www.socialsciences.leiden.edu/​psychology/​organisation/​cognitivepsychology/​staff/​staff/​poletiek.html


Fenna Poletiek is at the department of Cognitive Psychology. As a fellow of the Netherlands Royal Academy of Arts and Sciences, she started a research project on implicit grammar learning, in the late nineties, using experimental and computational approaches. She graduated on hypothesis testing behavior; a topic on which she published a monography. She is a member of the Leiden Institute for Brain and Cognition. Finally, she acts as an advisor of the National Police Agency and the prosecution for cases of sexual abuse involving witnesses by young children, or victims reporting recovered memories. She lectures at both the bachelor and master level, on Decision Making and Cognitive Psychology. She is coordinator of the Honours Programs for the most excellent 1st  and 3rd years bachelor students.

Research Interests

1. Cognitive grammar induction
In 1997 a research project on cognitive grammar induction was started. Grammar induction is the phenomenon that people abstract structure knowledge from stimuli being generated by that structure. The most fascinating case obviously is natural grammar learning. We study the phenomenon experimentally by using artificial languages and artificial grammars. Mostly, behavioral measures like reaction times and learning curves are observed, and currently EEG studies are in preparation. We propose statistical models to generate predictions and account for our observations.
As a distinctive feature of our approach, we explain successful grammar induction as a result of a narrow fit between general cognitive learning mechanisms and features of the environmental input. Moreover, we study the process of learning itself: for example, Esther van den Bos found unconscious goal directed grammar learning. In her experiments, learners unconsciously selected only the most simple structures in the stimuli they needed to carry out their task. Grammar learning seems to be an unconscious but goal directed learning process that exploits characteristics of the environment and relies on basic general learning mechanisms.

Collaboration
Among others;
Dr Esther van den Bos. Post doc (Amsterdam University; Leiden University)
Jun Lai. (PhD student): Sampling characteristics of stimuli in artificial grammar learning.
Prof. dr Niels Schiller (Leiden University)
Dr Meinou de Vries (Max Planck Institute, Radboud University, Nijmegen)
Dr A. Verhagen (Leiden University; Department of Linguistics) )
Prof dr Nick Chater (Department of Psychology, UCL, UK)
Prof. dr. Padraic Monaghan (University of Lancaster, UK, Department of Psychology)
Prof dr Morten Christiansen (Cornell University, USA)

2. Hypothesis testing behaviour

In this project (a follow up of Fenna Poletiek’s own PhD thesis) we take a close look at the implications of Popper’s falsificationism for psychological theories of hypothesis testing behaviour. The theoretical part led to the conclusion that falsificationism is undistinguishable from confirmationism. That is, no model of falsificationistic behaviour can be developed that isn’t also a confirmationistic model. Behaving as a good falsificationist is necessarily behaving as a good confirmationist. This is true under reasonable minimal assumptions. We found some experimental evidence (with Wason’s rule discovery task paradigm) that people indeed feel unable to think of a ‘falsifying’ way of testing their hypotheses, and that their attempts to falsify intuitively coincides with trying to get the most convincing confirmation..

3. (Illusory) Memory
Recently, an experimental project on illusory memory was started, motivated partly by the advice work done for the National Police Services Agency on accusations of sexual abuse. The accusations of sexual abuse analyzed for the Police, are sometimes based on memory reports from (occasionally very small) children or adults reporting recovered memories. We investigate the influences on these memories, using the experimental DRM paradigm in which participants study lists of words about a theme. When asked to retrieve the words they studied, participants name new words related to the theme but not studied.
Interestingly, illusory memory can be linked to grammar learning, and seems partly influenced by the same factors affecting grammar induction. Both processes involve ‘extracting’ common features from a set of mutually related stimuli; in illusory memory this common feature is a semantic theme, in grammar induction, it is sequential rules.

4. Applied Cognitive Psychology.
Fenna Poletiek is involved in research, consulting and teaching in the field of legal decision making. In 2006, she has been appointed as a member of the National Experts Group on Special Legal Cases of Sexual Abuse (LEBZ). This group is part of the National Police Services Agency (KLPD). The expert group (consisting of four cognitive psychologists among whom W. A. Wagenaar) have been appointed by the Minister of Justice to advice in cases of reports on sexual abuse, especially cases that are hard to judge on veracity. Examples are accusations based on experiences reported by very young children or accusations based on ‘recovered memories’.

Fenna Poletiek and Bernet Elzinga in LEBZ (in Dutch only)
From 1994 to 1997 Fenna Poletiek worked at the National Research Institute for Mental Health (Trimbos Institute). She conducted an effect study of the new law on coercive hospitalization of mentally ill, ordered by the Ministry of Justice and the Ministry of Health.

Teaching & Supervision

Bachelor courses and research (in Dutch only)


Master courses
PhD supervision
  • Dr Esther van den Bos (graduated in 2007) Implicit Artificial Grammar Learning. Unpublisehd PhD thesis.
  • Jun Lai, MSc. Currently working on the project: The influence of sampling characteristics of the stimuli on grammar induction.

Grants & fellowships

2011 Visitor’s fellowship (September to December) Max Planck Institute for Psycholinguistics, Nijmegen
2009 Traveling grant from the Leiden University Fund
2003 NWO-PhD project granted in Open Competition Grant program.
1999 Publication grant by NWO for writing the monograph: ‘Hypothesis testing behavior’ published with Psychology Press
1997-2003 Several travel grants from KNAW during fellowship
1997-2003 Fellow of the Netherlands Royal Academy of Arts and Sciences (Koninklijke Nederlandse Akademie van Wetenschappen) at Leiden University. Project: Cognitive grammar induction.

Awards
1998 ‘Schloessmann Award for outstanding research paper’, Max Planck Institute, Berlin, on Non Pecuniary Damages in Cases of Legal Liability
1989 Prize for the 'best paper of the Volume1988' of the Maandblad Geestelijke Volksgezondheid.

Other professional activities
2004- Editor of ‘de Psycholoog’
1987-1992 Editor of "Psychologie en Maatschappij"
1990 Visit of the Laboratory for Decision Research, University of Chicago
1994 Columnist of "De Psycholoog"

Languages

  • Native Dutch
  • Fluent in French and English

Last Modified: 24-03-2016