Biomedical subjects

S A Sloman

Publications and source records attributed to S A Sloman.

8 recordsLinked to original sources

PubMed2000

Perspective effects in nondeontic versions of the Wason selection task.

Perspective effects in the Wason four-card selection task occur when people choose mutually exclusive sets of cards depending on the perspective they adopt when making their choice. Previous demonstrations of perspective effects have been limited to deontic contexts--that is, problem contexts that involve social duty, like permissions and obligations. In three experiments, we demonstrate perspective effects in nondeontic contexts, including a context much like the original one employed by Wason (1966, 1968). We suggest that perspective effects arise whenever the task uses a rule that can be interpreted biconditionally and different perspectives elicit different counterexamples that match the predicted choice sets. This view is consistent with domain-general theories but not with domain-specific theories of deontic reasoning--for example, pragmatic reasoning schemas and social contract theory--that cannot explain perspective effects in nondeontic contexts.

Adult↗

PubMed2000

Reasoning versus text processing in the Wason selection task: a nondeontic perspective on perspective effects.

We argue that perspective effects in the Wason four-card selection task are a product of the linguistic interpretation of the rule in the context of the problem text and not of the reasoning process underlying card selection. In three experiments, participants recalled the rule they used in either a selection or a plausibility rating task. The results showed that (1) participants tended to recall rules compatible with their card selection and not with the rule as stated in the problem and (2) recall was not affected by whether or not participants performed card selection. We conclude that perspective effects in the Wason selection task do not concern how card selection is reasoned about but instead reflect the inferential text processing involved in the comprehension of the problem text. Together with earlier research that showed selection performance in nondeontic contexts to be indistinguishable from selection performance in deontic contexts (Almor & Sloman, 1996; Sperber, Cara, & Girotto, 1995), the present results undermine the claim that reasoning in a deontic context elicits specialized cognitive processes.

Attention↗

PubMed1999

Feature centrality: naming versus imagining.

Being white is central to whether we call an animal a "polar bear," but it is fairly peripheral to our concept of what a polar bear is. We propose that a feature is central to category naming in proportion to the feature's category validity--the probability of the feature, given the category. In contrast, a feature is conceptually central in a representation of the object to the extent that the feature is depended on by other features. Further, we propose that naming and conceptual centrality are more likely to disagree for features that hold at more specific levels (such as is white, which holds only for the specific category of polar bear) than for features that hold at intermediate levels of abstraction (such as has claws, which holds for all bears). In support of these hypotheses, we report evidence that increasing the abstractness of category features has a greater effect on judgments of conceptual centrality than on judgments of name centrality and that other category features depend more on intermediate-level category features than on specific ones.

Adult↗

PubMed1998

Categorical inference is not a tree: the myth of inheritance hierarchies.

One enduring principle of rational inference is category inclusion: Categories inherit the properties of their superordinates. In five experiments, I show that people do not consistently apply this principle when evaluating categorical arguments involving natural categories and a single nonexplainable predicate such as all electronic equipment has parts made of germanium, therefore all stereos have parts made of germanium. Participants frequently did not apply the category inclusion rule despite affirming the relevant categorical relation (e.g., stereos are electronic equipment). They failed to apply the rule even when categories were universally quantified unambiguously. Instead, judgments tended to be proportional to the similarity between premise and conclusion categories. Neglect of category inclusion relations was observed using arguments concerning natural kinds, artifacts, and social kinds.

Adult↗

PubMed1998

Similarity as an explanatory construct.

Theories can be found throughout cognitive science that give an explanatory role to similarity. Such theories can be contrasted with those that model thought using abstract rules. We lay out four possible explanatory roles for similarity. We then review the computational pros and cons of similarity- and rule-based models and outline the empirical work that speaks to the psychological plausibility of the two frameworks. We conclude that an adequate model of human thought must take advantage of both the flexibility of similarity-based inference and the compositionality and certainty associated with rule-based inference.

Attention↗

PubMed1994

When explanations compete: the role of explanatory coherence on judgements of likelihood.

The likelihood of a statement is often derived by generating an explanation for it and evaluating the plausibility of the explanation. The explanation discounting principle states that people tend to focus on a single explanation; alternative explanations compete with the effect of reducing one another's credibility. Two experiments tested the hypothesis that this principle applies to inductive inferences concerning the properties of everyday categories. In both experiments, subjects estimated the probability of a series of statements (conclusions) and the conditional probabilities of those conclusions given other related facts. For example, given that most lawyers make good sales people, what is the probability that most psychologists make good sales people? The results showed that when the fact and the conclusion had the same explanation the fact increased people's willingness to believe the conclusion, but when they had different explanations the fact decreased the conclusion's credibility. This decrease is attributed to explanation discounting; the explanation for the fact had the effect of reducing the plausibility of the explanation for the conclusion.

Cognition↗

PubMed1994

Similarity- versus rule-based categorization.

An influential study by Rips (1989) provides the strongest evidence available that categorization cannot be reduced to similarity. In Rips's study, subjects were presented a sparse description of an object that mentioned only a value on a single dimension (e.g., "an object 3 inches in diameter"), followed by two categories (e.g., pizza and quarter), where one allowed more variability on the relevant dimension than did the other (the diameter of pizzas is more variable than that of quarters). Subjects judged the described object to be more likely to be a member of the variable category (pizza), but more similar to the nonvariable category (quarter). This dissociation between categorization and similarity strongly implies that categorization was not based on similarity. In our first experiment, we used sparse descriptions like Rips's, as well as rich descriptions that contained features characteristic of the nonvariable category. We found that categorization tracked similarity with both kinds of descriptions. In a second experiment, we modified our procedure to be more like that of Rips's by requiring subjects to think aloud while making their decisions. Now, like Rips, we found a dissociation between similarity and categorization with sparse items; with rich descriptions, categorization again tracked similarity. These findings are consistent with the hypothesis that categorization can be done in two ways, by similarity and by rule. An exclusive reliance on rule-based categorization seems to occur only when the description of the to-be-categorized object does not contain any features characteristic of any relevant category.

Adult↗

PubMed1991

Congruency effects in part-list cuing inhibition.

In demonstrations of part-list cuing inhibition, subjects who are shown a subset of studied list words recall fewer noncue words than subjects not shown such part-list cues. We propose that part-list inhibition is governed in part by an incongruency principle: Inhibition occurs to the extent that part-list cues induce a retrieval framework different from that used to encode list items. In Experiment 1, word lists were studied followed by a test of free recall either without cues, or with cue words serially organized to be either congruent or incongruent with the order of studied items. In Experiments 2-4, cues consisted of every second study item in the original presentation order (congruent ones) or reordered to form famous names or familiar idioms that had been hidden in the study list (incongruent cues). More part-list inhibition was observed with incongruent cues than congruent cues in all 4 experiments.

Analysis of Variance↗