Biomedical subjects

Walter Schaeken

Publications and source records attributed to Walter Schaeken.

6 recordsLinked to original sources

PubMed2003

A critique of Oaksford, Chater, and Larkin's (2000) conditional probability model of conditional reasoning.

M. Oaksford, N. Chater, and J. Larkin (2000) proffered a Bayesian model in which conditional inferences are a direct function of conditional probabilities. In the current article, the authors first considered this model regarding the processing of negatives in conditional reasoning. Its predictions were evaluated against a large-scale meta-analysis (W. J. Schroyens, W. Schaeken, & G. d'Ydewalle, 2001b). This evaluation shows that the model is flawed: The relative size of the negative effects does not match predictions. Next, the authors evaluated the model in relation to inferences about affirmative conditionals, again considering the results of a meta-analysis (W. J. Schroyens, W. Schaeken, & G. d'Ydewalle, 2001a). The conditional probability model is countered by the data reported in literature; a mental models based model produces a better fit. The authors conclude that a purely probabilistic model is deficient and incomplete and cannot do without algorithmic processing assumptions if it is to advance toward a descriptively adequate psychological theory.

Conditioning, Psychological↗

PubMed2003

In search of counter-examples: deductive rationality in human reasoning.

Dual-process theories come in many forms. They draw on the distinction between associative, heuristic, tacit, intuitive, or implicit processes (System 1) and rule-based, analytic, explicit processes (System 2). We present the results of contextual manipulations that have a bearing on the supposed primacy of System 1 (Stanovich & West, 2000). Experiment 1 showed that people who evaluated logically valid or invalid conditional inferences under a timing constraint (N=56), showed a smaller effect of logical validity than did people who were not placed under a timing constraint (N= 44). Experiment 2 similarly showed that stressing the logical constraint that only inferences that follow necessarily are to be endorsed (N = 36) increased the size of the validity effect, as compared to that of participants (N=33) given the standard instruction to make "logical" inferences. These findings concur with the thesis in dual-processing frameworks that "Rationality-2 processes" (Evans & Over, 1996), "test procedures" (Chater & Oaksford, 1999), or "conclusion validation processes" (Johnson-Laird & Byrne, 1991; Schroyens, Schaeken, & d'Ydewalle, 2001) serve to override the results of System 1 processes.

Adolescent↗

PubMed2003

Inference suppression and semantic memory retrieval: every counterexample counts.

Reasoning with conditionals involving causal content is known to be affected by retrieval of counterexamples from semantic memory. In this study we examined the characteristics of this search process in everyday conditional reasoning. In Experiment 1 we manipulated the number (zero to four) of explicitly presented counterexamples (alternative causes or disabling conditions) for causal conditionals. In Experiment 2, using a generation pretest, we measured the number of counterexamples participants could retrieve for a set of causal conditionals. One month after the pretest, participants were presented a reasoning task with the same conditionals. The experiments indicated that acceptance of modus ponens linearly decreased with every additionally retrieved disabler, whereas affirmation of the consequent acceptance linearly decreased as a function of the number of retrieved alternatives. Results for denial of the antecedent and modus tollens were less clear. The findings show that the search process does not necessarily stop after retrieval of a single counterexample and that every additional counterexample has an impact on the inference acceptance.

Cognition↗

PubMed2002

The relative contribution of content and context factors on the interpretation of conditionals.

Previous research showed that conditional reasoning is affected by the content and the context of the studied problems. In this study, we investigate in detail the relative effect of three factors, namely the number of alternative or disabling reasons, speaker control, and pragmatic type, on the interpretation of conditionals. These factors were subject to prior research, but mostly in a fragmented way. This study indicates that some important nuances must be added to earlier findings. The number of alternatives and disablers, the speaker control, and the pragmatic type of conditional statements all have a considerable effect on how we interpret these sentences and reason with them, but they do not have equal weight. Alternatives/disablers play a significant but very limited role on the interpretation of conditionals, while the influence of speaker control and of pragmatic type is far more imperative.

Adult↗

PubMed2002

Causal conditional reasoning and semantic memory retrieval: a test of the semantic memory framework.

This study tested and refined a framework that proposes a mechanism for retrieving alternative causes and disabling conditions (Cummins, 1995) during reasoning. Experiment 1 examined the relation between different factors affecting retrieval. The test revealed high correlations between the number of possible alternative causes or disabling conditions and their strength of association and plausibility. Experiment 2 explored the hypothesis that due to a more extended search process, conditional inferences would last longer when many alternative causes or disabling conditions were available. Affirmation of the consequent (AC) and modus ponens (MP) latencies showed the hypothesized pattern. Denial of the antecedent (DA) and modus tollens (MT) inferences did not show latency effects. The experiment also identified an effect of the number of disabling conditions on AC and DA acceptance. Experiment 3 measured efficiency of disabler retrieval by a limited time, disabler generation task. As predicted, better disabler retrieval was related to lower acceptance of the MP and MT inferences.

Humans↗

PubMed2000

Heuristic and analytic processes in propositional reasoning with negatives.

The authors report 4 studies on heuristic and analytic processes in conditional reasoning with negations and show that a heuristic negative conclusion bias cannot account for the effects observed on problem-solving latencies derived from eye-movement measures (Experiment 1) and a novel mouse-tracking methodology (Experiment 2). A double negation elimination process can account for both the latency and response-frequency effects of a negation in the clause about which an inference is made. It is further shown that other negation effects cannot be explained by an affirmative premise bias proposed in the literature. Experiments 3 and 4 demonstrate that a novel availability hypothesis provides a viable alternative. It is argued that extant analytic theories need to be extended to incorporate a validating search for counter examples and need to specify how pragmatic and comprehension processes influence such a search.

Adult↗