Subproject I (Prof. Funke)

Statistical and Computational Modelling of  Basic Cognition, Complex Problem Solving and Real-Life Functioning

Evidence from neurological studies shows that there is a striking explanatory gap between the assessment of basic cognitive abilities in patients and their levels of real-life functioning. For example, Shallice & Burgess, (1991) report that patients with fronto-polar damage show average performance on cognitive measures and intelligence test, but fail in everyday life situations. Attempts to integrate findings across different levels of description are still rare, despite the growing insight that ultimately it is one single neuro-cognitive system that underlies all of human behaviour (Newell, 1990). To address this lack of theoretical integration we will use statistical and computational modeling to investigate the relations between three levels of behavioural and cognitive complexity of planning abiliy, starting from relevant basic cognitive abilities (i.e. working memory and response inhibition), over performance in complex problem solving tasks up to real-life functioning.

The proposed research will integrate clinical research on cognitive abilities (more precisely neuropsychological studies of planning and problem solving; e.g., Shallice & Burgess, 1991) with complex problem solving research conducted in the classical psychological tradition (e.g. Funke, 2001). These two branches of research have in common that both tried to address the problem of a lack of ecological validity of simple measures of cognitive functioning. Although developing independently, they have gradually converged and produced instruments for assessing planning ability at a comparable level of complexity that goes beyond typical laboratory tasks used to assess basic cognitive abilities. The research project proposed here will be the first to use instruments from both strands of research in a combined investigation of complex problem solving abilities. Moreover, in collaboration with Project IV,  the study will be conducted with a clinical sample of schizophrenics that are known to have planning and problem solving deficits as well as a sample of healthy participants. The results will be analysed in relation to underlying cognitive abilities and individual performance motivation, as well as in relation to real-life functional capacity. Furthermore, in order to investigate the interaction of basic cognition and deliberately learned and applied strategies, a training intervention will be conducted.

To take into account the theoretical integration of cognitive processes at different levels of complexity, we will apply two methods of analysis in parallel: A conventional path-analysis for macro-scale relationships on the psychometric level will be combined with a set of detailed cognitive models – written in the ACT-R cognitive architure (Anderson & Lebiere, 1998) – of the central complex planning task ‘Plan-a-Day’ (Funke & Krüger, 1995) and of the dynamic goal management task developed in Project II (Neurocognition). This will allow us to go beyond mere correlational analyses and to explore how individual differences in basic cognitive abilities and performance motivation influence complex cognition. In addition, this approach enables us to evaluate the degree to which complex problem solving serves as mediator between basic cognition, motivation, and real-life functional outcome. This approach will extend the insights gained from earlier modelling studies of how working memory capacity influences higher functions (e.g. Altman & Trafton, 2002). Finally, cognitive modelling (of the Goal Management Game task) will be tightly integrated with the neurophysiological studies conducted in Project II, with the aim of mapping model activations to neuronal activity (cf. Anderson et al. 2004, 2005).

The Plan-a-Day Task

With "Plan-a-Day" (PAD), we present a new diagnostic tool for assessing planning competencies. The instrume nt is based upon classical "daily errands" tasks, but is at the same time optimized with respect to several aspects:

• Semantic embedding is done according to a working environment. Subjects have to organize tasks like having a talk with a customer in the cafeteria, going to a meeting at the meeting hall, or picking up the daily news at the internal post office.
• Besides a training unit, there are two daily plans to solve. This repeated measurement should increase reliability of indicators.
• The different tasks have one of three types of priority (without, with low, and with high priority).
• The daily tasks are constructed in such a way that you could not solve all tasks for the day.
• There exists a "Joker" which can be used once during each day and which allows to drastically reduce driving time between the different locations.
• Based on the data registration during the planning phase, one can construct process oriented measures of planning competencies. This overcomes the currrent limitations of result oriented measures.
• The implemented tasks can be easily changed.

The interface from PAD (i.e., what subjects see on the screen of their PC) can be seen here, together with a short excerpt from the instruction. As you might see, a high-resolution color screen is necessary for optimal presentation.