"Prototypes in the mist: The early epochs of category learning": Correction to Smith and Minda (1998).

Reports an error in "Prototypes in the mist: The early epochs of category learning" by J. David Smith and John Paul Minda (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1998[Nov], Vol 24[6], 1411-1436). As a result of errors made in production, two equations in the article were printed incorrectly. The corrected equations are included in the erratum. (The following abstract of the original article appeared in record 1998-12790-005.) Recent ideas about category learning have favored exemplar processes over prototype processes. However, research has focused on small, poorly differentiated categories and on task-final performances--both may highlight exemplar strategies. Thus, we evaluated participants' categorization strategies and standard categorization models at successive stages in the learning of smaller, less differentiated categories and larger, more differentiated categories. In the former case, the exemplar model dominated even early in learning. In the latter case, the prototype model had a strong early advantage that gave way slowly. Alternative models, and even the behavior of individual parameters within models, suggest a psychological transition from prototype-based to exemplar-based processing during category learning and show that different category structures produce different trajectories of learning through the larger space of strategies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning mode and exemplar sequencing in unsupervised category learning.

Exemplar sequencing effects in incidental and intentional unsupervised category learning were investigated to illuminate how people form categories without an external teacher. Stimuli were perfectly separable into 2 categories based on 1 of 2 dimensions of variation. Sequencing of the first 20 training stimuli was manipulated. In the blocked condition, 10 Category A stimuli were followed by 10 Category B stimuli. In the intermixed condition, these 20 stimuli were ordered randomly. Experiment 1 revealed an interaction between learning mode and sequence, with better intentional learning for intermixed sequences but better incidental learning for blocked sequences. Experiment 2 showed that manipulating trial-to-trial variability along each dimension can impact intentional learning. Training sequences that emphasized variation along the category-relevant dimension resulted in better performance than sequences that emphasized variation along the category-irrelevant dimension. The results suggest that unsupervised category learning is influenced by the mode of learning and the order and nature of encountered exemplars. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Delayed feedback effects on rule-based and information-integration category learning.

The effect of immediate versus delayed feedback on rule-based and information-integration category learning was investigated. Accuracy rates were examined to isolate global performance deficits, and model-based analyses were performed to identify the types of response strategies used by observers. Feedback delay had no effect on the accuracy of responding or on the distribution of best fitting models in the rule-based category-learning task. However, delayed feedback led to less accurate responding in the information-integration category-learning task. Model-based analyses indicated that the decline in accuracy with delayed feedback was due to an increase in the use of rule-based strategies to solve the information-integration task. These results provide support for a multiple-systems approach to category learning and argue against the validity of single-system approaches. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prototypes in category learning: The effects of category size, category structure, and stimulus complexity.

Although research in categorization has sometimes been motivated by prototype theory, recent studies have favored exemplar theory. However, some of these studies focused on small, poorly differentiated categories composed of simple, 4-dimensional stimuli. Some analyzed the aggregate data of entire groups. Some compared powerful multiplicative exemplar models to less powerful additive prototype models. Here, comparable prototype and exemplar models were fit to individual-participant data in 4 experiments that sampled category sets varying in size, level of category structure, and stimulus complexity (dimensionality). The prototype model always fit the observed data better than the exemplar model did. Prototype-based processes seemed especially relevant when participants learned categories that were larger or contained more complex stimuli. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predicting transfer performance: A comparison of competing function learning models.

The population of linear experts (POLE) model suggests that function learning and transfer are mediated by activation of a set of prestored linear functions that together approximate the given function (Kalish, Lewandowsky, & Kruschke, 2004). In the extrapolation-association (EXAM) model, an exemplar-based architecture associates trained input values with their paired output values. Transfer incorporates a linear rule-based response mechanism (McDaniel & Busemeyer, 2005). Learners were trained on a functional relationship defined by 2 linear-function segments with mirror slopes. In Experiment 1, 1 segment was densely trained and 1 was sparsely trained; in Experiment 2, both segments were trained equally, but the 2 segments were widely separated. Transfer to new input values was tested. For each model, training performance for each individual participant was fit, and transfer predictions were generated. POLE generally better fit the training data than did EXAM, but EXAM was more accurate at predicting (and fitting) transfer behaviors. It was especially telling that in Experiment 2 the transfer pattern was more consistent with EXAM's but not POLE's predictions, even though the presentation of salient linear segments during training dovetailed with POLE's approach. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Base-rate effects in category learning: A comparison of parallel network and memory storage-retrieval models.

Exemplar-memory and adaptive network models were compared in application to category learning data, with special attention to base rate effects on learning and transfer performance. Subjects classified symptom charts of hypothetical patients into disease categories, with informative feedback on learning trials and with the feedback either given or withheld on test trials that followed each fourth of the learning series. The network model proved notably accurate and uniformly superior to the exemplar model in accounting for the detailed course of learning; both the parallel, interactive aspect of the network model and its particular learning algorithm contribute to this superiority. During learning, subjects' performance reflected both category base rates and feature (symptom) probabilities in a nearly optimal manner, a result predicted by both models, though more accurately by the network model. However, under some test conditions, the data showed substantial base-rate neglect, in agreement with M. A. Gluck and G. H. Bower (see record 1989-00340-001). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of diagnostic category and reinforcer on learning without awareness.

Learning without awareness was tested by asking Ss to construct sentences using pronouns (I, we, he, they) and verbs presented to them. 3 groups were employed—normals, neurotics, and schizophrenics, under 4 experimental conditions: (a) E "rewarded" (said "good" to) 2 of the pronouns (I, we); (b) the use of he or they was "punished" ("not so good"); (c) differential reinforcement as was appropriate re: "punishment" and "reward" when employing the pronouns; (d) control. Results: normals profited well from all conditions of reinforcement; neurotics, only from reward or reward and punishment; schizophrenics, from punishment alone. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Incidental concept learning, feature frequency, and correlated properties": Correction to Wattenmaker.

Reports an error in "Incidental concept learning, feature frequency, and correlated properties" by William D. Wattenmaker (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1993[Jan], Vol 19[1], 203-222). This article included three typographical errors in the statistics. The corrected statistics are provided in the erratum. (The following abstract of the original article appeared in record 1993-16363-001.) Four experiments examined sensitivity to feature frequencies and feature correlations as a function of intentional and incidental concept learning. Feature frequencies were encoded equally well across variations in learning strategies, and although classification decisions in both intentional and incidental conditions preserved correlated features, this sensitivity was achieved through different processes. With intentional learning, sensitivity to correlations resulted from explicit rules, whereas incidental encoding preserved correlations through a similarity-based analogical process. In incidental tasks that promoted exemplar storage, classification decisions were mediated by similarity to retrieval examples, and correlated features were indirectly preserved in this process. Results are discussed in terms of the diversity of encoding processes and representations that can occur with incidental category learning. [An erratum concerning this article appears in Journal of Experimental Psychology: Learning, Memory, and Cognition, 1993(Mar), Vol 19(2). The statistics on page 211 are corrected.] (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Making a silk purse out of two sow's ears: Young children's use of comparison in category learning.

Comparison mechanisms have been implicated in the development of abstract, relational thought, including object categorization. D. Gentner and L. L. Namy (1999) found that comparing 2 perceptually similar category members yielded taxonomic categorization, whereas viewing a single member of the target category elicited shallower perceptual responding. The present experiments tested 2 predictions that follow from Gentner and Namy's (1999) model: (a) Comparison facilitates categorization only when the targets to be compared share relational commonalities, and (b) providing common labels for targets invites comparison, whereas providing conflicting labels deters it. Four-yr-olds participated in a forced-choice task. They viewed 2 perceptually similar target objects and were asked to "find another one." Results suggest an important role for comparison in lexical and conceptual development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Working memory and connectionist models of parsing: A reply to MacDonald and Christiansen (2002).

The authors take issue with 3 claims made by M. C. MacDonald and M. H. Christiansen (2002): (a) tha connectionist models of syntactic processing do not have components that function in the sarne way as limitations on working memory (WM) in production system models of psychological processes; (b) that individual differences in WM are related to the efficiency of syntactic processing because both are affected by reading experience; and (c) that individual differences in the nature of phonologica representations affect the efficiency of syntactic processing. The authors argue that the concept of WM cannot be eliminated from models of language processing and that the literature supports the view that syntactic processing involves a specialized WM system. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Subtyping versus bookkeeping in stereotype learning and change: Connectionist simulations and empirical findings.

A distributed connectionist network can account for both bookkeeping (M. Rothbart, 1981) and subtyping (M. B. Brewer, V. Dull, & L. Lui, 1981; S. E. Taylor, 1981) effects. The finding traditionally regarded as demonstrating subtyping is that exposure to moderate (compared with extreme) disconfirmers leads to subsequent ratings of the group that are less stereotypic. Despite learning that is incremental and analogous to bookkeeping, the simulations replicate this finding and suggest that the "subtyping" pattern of results will be drastically reduced if disconfirmers are encountered before the stereotype is well-established. This novel prediction holds with human participants and offers a tantalizing suggestion: Although moderate disconfirmers may produce more stereotype change, stereotype development might be discouraged by exposure to either extreme or moderate disconfirmers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recency effects as a window to generalization: Separating decisional and perceptual sequential effects in category learning.

Accounts of learning and generalization typically focus on factors related to lasting changes in representation (i.e., long-term memory). The authors present evidence that shorter term effects also play a critical role in determining performance and that these recency effects can be subdivided into perceptual and decisional components. Experimental results based on a probabilistic category structure show that the previous stimulus exerts a contrastive effect on the current percept (perceptual recency) and that responses are biased toward or away from the previous feedback, depending on the similarity between successive stimuli (decisional recency). A method for assessing these recency effects is presented that clarifies open questions regarding stimulus generalization and perceptual contrast effects in categorization and in other domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Use of analogy in learning scientific concepts": Correction to Donnelly and McDaniel.

Reports an error in "Use of analogy in learning scientific concepts" by Carol M. Donnelly and Mark A. McDaniel (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1993[Jul], Vol 19[4], 975-987). The captions for Figures 1 and 2 on pp. 979 and 980, respectively, were transposed. The figures and the correct captions are included in the erratum. (The following abstract of the original article appeared in record 1993-44140-001.) Four experiments compared learning of scientific concepts as expressed in either traditional literal form or through an analogy. Comprehension of basic-level details and inferential implications was measured through multiple-choice testing. In Exp 1, literal or analogical renditions were presented in textual form only. In Exp 2, text was accompanied by a dynamic video. In Exp 3, the video and text literal rendition was compared with a text-only analogical rendition. In Exp 4, Ss read only about a familiar domain. Ss consistently answered basic-level questions most accurately when concepts were expressed literally, but answered inferential questions most accurately when concepts were expressed analogically. Analysis of individual differences (Exp 2) indicated that this interaction strongly characterized the conceptual learning of science novices. The results are discussed within the framework of schema induction. [A correction to this article appears in Journal of Experimental Psychology: Learning, Memory, and Cognition, 1993, Vol 19(5), 1093. The captions for Figures 1 and 2 are corrected.] (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Nature of priming effects in semantic matching": Correction to Whitlow.

Reports an error in "Nature of priming effects in semantic matching" by J. W. Whitlow (Journal of Experimental Psychology: Learning, Memory, and Cognition, 1986[Jul], Vol 12[3], 353-360). The Appendix table was constructed incorrectly. The correct table appears in the erratum. (The following abstract of the original article appeared in record 1986-29114-001.) Studied priming effects in a semantic matching task that distinguished visually based matching processes from nominally and semantically based matching processes, using 24 undergraduates. Ss judged semantic matches for 3 types of word pairs: identical (e.g., robin-robin), same category (e.g., robin-sparrow), and different category (e.g., robin-truck). Visual matching was isolated by comparing performance between physical identity (e.g., robin-robin) and nominal identity (e.g., robin-ROBIN) pairs. Physical identity pairs, which allowed visually based matching, exhibited an interaction between priming and the typicality of category exemplars that was absent in nominal identity and same-category pairs. Priming had no effect on nominal identity pairs. For same-category pairs, which required semantically based matching, priming produced facilitation at all levels of typicality. The results bring the semantic matching paradigm into agreement with other procedures that show that priming facilitates processing for all related targets. Categories and exemplars used as stimulus materials are appended. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A possible role of the striatum in linear and nonlinear category learning: Evidence from patients with Hungtington's disease.

Linear and nonlinear categorization rule learning was examined in patients with Huntington's disease (HD) and a group of controls using the perceptual categorization task. Participants learned to categorize simple line stimuli into 1 of 2 categories over 600 trials. In addition to traditional measures of accuracy, quantitative model-based analyses were applied to each participant's data to characterize better the nature of any observed deficits. In the linear rule condition, HD patients displayed an early-training deficit relative to controls, whereas later in training the HD patients were not statistically different from controls. In the nonlinear rule condition, HD patients displayed both an early- and late-training deficit. The quantitative model-based analyses revealed that the HD patients' deficits in the linear condition were due to an impairment in learning the experimenter-defined rule and not in applying a learned rule inconsistently. In the nonlinear condition, in contrast, the HD patients' deficits were due to an impairment in learning the experimenter-defined rule and in applying a learned rule inconsistently. Overall, these results suggest that HD can result in a deficit in learning both linear and nonlinear categorization rules. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prototype and Exemplar Accounts of Category Learning and Attentional Allocation: A Reassessment.

In a recent article. J. P. Minda and J. D. Smith (2002; see record 2002-00620-002) argued that an exemplar model provided worse quantitative fits than an alternative prototype model to individual subject data from the classic D. L. Medin and M. M. Schaffer (1978) 5/4 categorization paradigm. In addition, they argued that the exemplar model achieved its fits by making untenable assumptions regarding how observers distribute their attention. In this article, we demonstrate that when the models are equated in terms of their response-rule flexibility, the exemplar model provides a substantially better account of the categorization data than does a prototype or mixed model. In addition, we point to shortcomings in the attention-allocation analyses conducted by J. P. Minda and J. D. Smith (2002). When these shortcomings are corrected, we find no evidence that challenges the attention-allocation assumptions of the exemplar model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The development of schemes for recognizing additive and alternative effects in a "natural experiment" context.

20 Ss at each of 4 age levels (4th, 6th, and 8th grade and college) were presented a "natural experiment" problem situation in which they were asked to interpret the more complex situations in which (a) either of 2 alternative variables is sufficient to produce an outcome, or (b) 2 variables are additive in their effect on an outcome. Not until adolescence could Ss isolate alternative or additive causes in a multivariable situation, though it is speculated they may comprehend the concept of alternative causes well before this age. Only 65% of college Ss exhibited correct reasoning in one or both situations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

On learning and development, Piagetian style: I. A reply to Lefebvre-Pinard.

Examines the equilibration theory of Piaget (learning vs development, stage transitions) to make more explicit the methodological foundations of B. Inhelder et al (1974). In this connection, the "problem-solving" learning method used by these authors is analyzed by means of the new concept of "learning loops." Similarly, the successful equilibration learning method used by M. Lefebvre and A. Pinard (1974) is analyzed and shown to involve executive facilitation and chunking (coordination) of 2 crucial schemes. A process-structural model of conservation acquisition previously developed by the present author, and its empirical tests by R. Case (1975) and by G. M. Parkinson (1975), are used to illustrate and to empirically support the process-structural differences theoretically found between these 2 equilibration methods. (54 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)