Christoph T. Weidemann

Lecturer at the Department of Psychology [link]

Swansea University
Singleton Park
Swansea, SA2 8PP
Wales, UK
Phone: +1-215-573-3365
Fax: +1-215-746-6848
E-mail: ctw@cogsci.info [e-mail]

Research Interests

Cognitive processes, such as those involved in perception, memory and decision making, are highly context dependent. Previous experiences, expectations, and goals all shape how sensory input is transformed into percepts, how memories are stored and retrieved and how available information is evaluated to guide behaviour. This feature of human information processing is fascinatingly pervasive and can be easily experienced, especially in cases when it leads to errors. For example, it is often difficult to identify a familiar face outside of its usual context ("the butcher on the bus" phenomenon) and the the erroneous repetition of written words often goes unnoticed ("repetition blindness"; an example is embedded in this very sentence). Despite leading to errors in some cases, the integration of context with current processing is integral to cognition because it constitutes the foundation for learning and adaptive behaviour. My research investigates how context shapes human information processing. To this end I measure accuracy and speed of overt behaviour as well as activity in the human brain as assessed with tools such as electroencephalography (EEG), magnetoencephalography (MEG) and direct recordings from electrodes that are implanted in the brains of neurosurgery patients. A particular emphasis of my work is on the development of precise theoretical accounts (mathematical models) of cognitive processes that are informed and constrained by measured overt behaviour and brain activity.

Graduate education & previous work experience

October, 2006 – March, 2010:: Post-doctoral research fellow at the Computational Memory Lab
Department of Psychology, University of Pennsylvania, USA; supervisor: Prof. Michael J. Kahana
August, 2006:: PhD in psychology and cognitive science (minors in neuroscience and statistics)
Indiana University, Bloomington, USA; adviser: Prof. Richard M. Shiffrin
Spring & Summer, 2004:: Pre-doctoral research fellow at the Center for Adaptive Behavior and Cognition
Max Planck Institute for Human Development, Berlin, Germany
September, 2002:: Diplom (German degree similar to MS/MA ) in psychology
University of Bonn, Germany

Papers

I had to transfer the copyright for some of the articles listed below to the publishers of the journals in which they appeared. However, I am allowed to distribute copies to individuals for personal and/or research use. Your click on any of the links below constitutes your request to me for a personal copy of the linked article. A detailed copyright notice appears in the articles. Nature's web debates published an interesting relevant article by Richard M. Stallman titled "Science must `push copyright aside´" [link] .

Peer reviewed articles

Other manuscripts (available upon request)

Davelaar, E. J., Huber, D. E., Xing, T., & Weidemann, C. T. A habituation account of change detection in same/different judgments Manuscript in preparation.
Kahana, M. J., Miller, J. F., & Weidemann, C. T. Recall termination in free recall. Manuscript submitted for publication.
Mueller, S. T. & Weidemann, C. T. Alphabetic letter perceivability, similarity, and bias. Manuscript in preparation.
Weidemann, C. T., Solway, A., Kahana, M. J., & Fried, I. Single neurons in the human brain encode task context. Manuscript submitted for publication.
Weidemann, C. T., & Rieskamp, J. Is human covariation assessment based on Bayesian inference? Manuscript in preparation.

Weidemann, C. T. (2006). Identifying brief stimuli. Perceptual, preferential, and decisional aspects. Unpublished doctoral dissertation. Departments of Psychological & Brain Sciences and Cognitive Science, Indiana University, Bloomington.

Weidemann, C. T. (2002). Effects of prime duration and location in perceptual identification. Unpublished Diplom thesis. Department of Psychology, University of Bonn, Germany.

Quality links

Selected colleagues and collaborators:

David E. Huber: Assistant professor at the Psychology Department, University of California, San Diego
Michael J. Kahana: Professor at the Psychology Department, University of Pennsylvania
Shane T. Mueller: Senior Research Scientist at Klein Associates Division of ARA, Inc.
Jörg Rieskamp: Professor at the Psychology Department, University of Basel, Switzerland
Richard M. Shiffrin: Professor at the Department of Psychological and Brain Sciences, Indiana University
Sean Polyn: Consummate scientician

Great software for science:

Below I am posting links to a few selected programs (not written by me) that I find particularly useful for scientific work. All programs linked below are free in the sense that anyone may download, install, use, modify, and re-distribute them (detailed information can be found on the respective websites linked below). This freedom is particularly valuable for scientific work, because it allows the free sharing of one's work with collaborators, colleagues, students, or anyone else without requiring permission of the copyright holder of the associated program. All the programs linked below run on a variety of platforms such as Linux, Windows, and Mac OS.

The Python programming language: A nice object oriented programming language, well suited for scientific computing. Of particular interest are Scientific Python (SciPy) and other tools offered by Enthought as well as the Python Experiment Programming Library (PyEPL) and the plotting library Matplotlib . Substantial documentation is available on the Python documentation website .

The R project for statistical computing: A powerful software environment for statistical computing and graphics. Users of Emacs or XEmacs will enjoy the Emacs Speaks Statistics (ESS) mode. Other great languages for scientific computing include Octave , Scilab , and Maxima and there is also a Python interface for R called RPy . Extensive documentation for each of these programs is available at the respective websites.

LaTeX: A high-quality document preparation and typesetting system optimised for technical and scientific documents. Also useful for creating presentations (e.g., with the Beamer class) and posters (e.g., with Per Sederberg's Tkboxen style [available upon request]).

Unison: A great file synchroniser. Not directly science related, but useful for anybody who regularly uses more than one computer and wants to keep them synchronised.

By popular request: How to pronounce my name

IPA: [link] [kɹɪstʰɔf vaɪdəman]
My first name is pronounced similarly to the English pronunciation of "Christopher" without the final "er" sound.
My last name sounds somewhat like the American-English pronunciation of "vitamin".
Here is a recording in three audio formats: ogg [OGG] / mp3 [MP3] / wav [WAV]