Memory activation and the availability of explanations in sequential diagnostic reasoning.

Abstract

In the field of diagnostic reasoning, it has been argued that memory activation can provide the reasoner with a subset of possible explanations from memory that are highly adaptive for the task at hand. However, few studies have experimentally tested this assumption. Even less empirical and theoretical work has investigated how newly incoming observations affect the availability of explanations in memory over time. In this article we present the results of 2 experiments in which we address these questions. While participants diagnosed sequentially presented medical symptoms, the availability of potential explanations in memory was measured with an implicit probe reaction time task. The results of the experiments were used to test 4 quantitative cognitive models. The models share the general assumption that observations can activate and inhibit explanations in memory. They vary with respect to how newly incoming observations affect the availability of explanations over time. The data of both experiments were predicted best by a model in which all observations in working memory have the same potential to activate explanations from long-term memory and in which these observations do not decay. The results illustrate the power of memory activation processes and show where additional deliberate reasoning strategies might come into play.

Memory indexing of sequential symptom processing in diagnostic reasoning

“…Process models of diagnostic reasoning postulate selective and changing activation of hypotheses in working memory during sequential symptom processing (Mehlhorn et al, 2011). To observe correlates of these memory dynamics, we have assigned the hypotheses to spatial locations and applied eye tracking for process tracing.…”

“…Diagnostic reasoning with limited information search, for example, when clinical cases are presented as case histories, requires information integration based on knowledge and multiple probabilistic cues. In the present study, we used the cover story of an accident in a chemical plant, in which workers were affected by one of four chemicals (Mehlhorn, Taatgen, Lebiere, & Krems, 2011). Participants had to decide, which chemical had caused a worker's symptoms.…”

Temporal Dynamics of Hypothesis Generation: The Influences of Data Serial Order, Data Consistency, and Elicitation Timing

“…If the previously generated hypotheses fall below some threshold of agreement with the newly acquired data they are purged from working memory. Recent work by Mehlhorn et al (2011) also investigated the influence of consistent and inconsistent cues on the memory activation of hypotheses. They utilized a clever adaptation of the lexical decision task to assess the automatic memory activation of hypotheses as data were presented and found memory activation sensitivity to the consistency of the data.…”

How to implement HyGene into ACT-R

“…Mehlhorn, Taatgen, Lebiere, and Krems (2011) set forth to investigate how the dynamics of information acquisition influence the hypothesis generation process. In so doing, Mehlhorn et al (2011) resorted to the cognitive architecture ACT-R (Anderson, 2007), which they used to construct 4 models of hypothesis generation. The 4 models weighted differently each piece of information currently in the focus of attention.…”