Relational learning with and without awareness: transitive inference using nonverbal stimuli in humans

Learning complex relationships among items and representing them flexibly have been shown to be highly similar in function and structure to conscious forms of learning. However, it is unclear whether conscious learning is essential for the exhibition of flexibility in learning. Successful performance on the transitive inference task requires representational flexibility. Participants learned four overlapping premise pairs (A > B, B > C, C > D, D > E) that could be encoded separately or as a sequential hierarchy (A > B > C > D > E). Some participants (informed) were told prior to training that the task required an inference made from premise pairs. Other participants (uninformed) were told simply that they were to learn a series of pairs by trial and error. Testing consisted of unreinforced trials that included the non-adjacent pair, B versus D, to assess capacity for transitive inference. Not surprisingly, those in the informed condition outperformed those in the uninformed condition. After completion of training and testing, uninformed participants were given a postexperimental questionnaire to assess awareness of the task structure. In contrast with expectations, successful performance on the transitive inference task for uninformed participants does not depend on or correlate with postexperimental awareness. The present results suggest that relational learning tasks do not necessarily require conscious processes.

How two causes are different from one: the use of (un)conditional information in Simpson's paradox

In a causally complex world, two (or more) factors may simultaneously be potential causes of an effect. To evaluate the causal efficacy of a factor, the alternative factors must be controlled for (or conditionalized on). Subjects judged the causal strength of two potential causes of an effect that covaried with each other, thereby setting up a Simpson's paradox--a situation in which causal judgments should vary widely depending on whether or not they are conditionalized on the alternative potential cause. In Experiments 1 (table format) and 2 (trial-by-trial format), the subjects did conditionalize their judgments for one causal factor on a known alternative cause. The subjects also demonstrated that they knew what information was needed to properly make causal judgments when two potential causes are available. In Experiment 3 (trial-by-trial), those subjects who were not told about the causal mechanism by which the alternative cause operated were less likely to conditionalize on it. However, the more a subject recognized the covariation between the alternative cause and the effect, the more the subject conditionalized on it. Such behavior may arise from the interaction between bottom-up and top-down processing.

Analogical priming via semantic relations

Research on semantic memory has often tacitly treated semantic relations as simple conduits for spreading activation between associated object concepts, rather than as integral components of semantic organization. Yet conceptual relations, and the role bindings they impose on the objects they relate, are central to such cognitive tasks as discourse comprehension, inference, problem solving, and analogical reasoning. The present study addresses the question of whether semantic relations and their bindings can influence access to semantic memory. The experiments investigated whether, and under what conditions, presenting a prime pair of words linked by 1 of 10 common semantic relations would facilitate processing of a target pair of words linked by the same relation. No effect was observed when participants merely read the prime; however, relational priming was observed under instructions to note and use the semantic relations. Participants were faster at making a lexical decision or naming a word on a related pair of target words when that pair was primed with an analogously related pair of words than when the prime pair consisted of either two unrelated words or two words linked by some other relation. This evidence of analogical priming suggests that under an appropriate strategic set, lexical decisions and naming latencies can be influenced by a process akin to analogical mapping.

Pragmatics in analogical mapping

Theories of analogical reasoning differ in the roles they ascribe to pragmatic factors as a source of constraints on analogical mappings. The multiconstraint theory as instantiated in the ACME model (Holyoak & Thagard, 1989a) claims that pragmatic constraints interact with structural and semantic constraints within the mapping stage itself, in addition to influencing pre-mapping and post-mapping stages. Participants in three experiments were asked to generate mappings between non-isomorphic analogs for which mappings for some elements were ambiguous on structural grounds. In all experiments, manipulations of participants' processing goals influenced their preferred mappings. At the same time, goal-irrelevant information contributed to many-to-one mappings (Experiments 1 and 2) and to the resolution of mappings that were ambiguous on the basis of goal-relevant information alone (Experiment 3). The qualitative pattern of results was successfully simulated using the ACME model, implementing the impact of processing goals as an inhibitory process of selective attention.

On the status of inhibitory mechanisms in cognition: memory retrieval as a model case

Theories of cognition frequently assume the existence of inhibitory mechanisms that deactivate mental representations. Justifying this assumption is difficult because cognitive effects thought to reflect inhibition can often be explained without recourse to inhibitory processes. This article addresses the uncertain status of cognitive inhibitory mechanisms, focusing on their function in memory retrieval. On the basis of a novel form of forgetting reported herein, it is shown that classical associative theories of interference are insufficient as accounts of forgetting and that inhibitory processes must be at work. It is argued that inhibitory processes are used to resolve computational problems of selection common to memory retrieval and selective attention and that retrieval is best regarded as conceptually focused selective attention.