Cognitive models of decision making. Why precision matters

PhD ceremony: Ms. S.K. Mehlhorn, 12.45 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Cognitive models of decision making. Why precision matters

Promotor(s): prof. N.A. Taatgen

Faculty: Mathematics and Natural Sciences

Already in the 1970s, Allen Newell warned that verbal theories and simplifying dichotomies are not sufficient to understand human cognition. Yet, underspecified verbal models and binary oppositions still enjoy great popularity. In my thesis I have used the precision provided by computational cognitive models to challenge such simplifying dichotomies. The first part of the thesis centers on a dichotomy that currently receives much attention: Is reasoning based on implicit, automatic, or on explicit, deliberate processes? To study this question we conducted several behavioral experiments in which participants had to generate diagnoses for observed medical symptoms. In the experiments we measured the availability of diagnostic hypotheses in memory as a function of the present and past environment. We then compared the behavioral data to results of different computational models. Our findings suggest that automatic activation processes regulate the availability of diagnostic hypotheses in memory and thereby influence which hypotheses can be used by deliberate reasoning strategies. In the second part of the thesis, we moved on to another currently popular dichotomy: Can decisions better be described by non-compensatory heuristics or by compensatory decision strategies? Again, we compared the results of behavioral experiments to a number of computational models. We found that human data was best fit by models that incorporated non-compensatory as well as compensatory components. We conclude that apparently opposing aspects of cognition, such as automatic and deliberate reasoning, or non-compensatory and compensatory decision making, should better be understood as complementary components of cognition.