The information acquired during artificial grammar learning.

In an artificial grammar learning task, amnesic patients classified test items as well as normal Ss did. Item similarity did not affect grammaticality judgments when similar and nonsimilar test items were balanced for the frequency with which bigrams and trigrams (chunks) that appeared in the training set also appeared in the test items. Amnesic Ss performed like normal Ss. Results suggest that concrete information about letter chunks can influence grammaticality judgments and that this information is acquired implicitly. The similarity of whole test items to training items does not appear to affect grammaticality judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Defining the knowledge units of a synthetic language: Comment on Vokey and Brooks (1992).

J. R. Vokey and L. R. Brooks (see record 1992-18658-001) reported a set of experiments intended to demonstrate that judgments of grammaticality are determined by 2 characteristics of the test items: their similarity with a specific study item and their conformity with an abstract representation of the generative grammar. The author argues that both effects may be encompassed within a unified account, which requires neither a specific-item retrieval process nor an abstractive capacity. The basic assumption is that the primary knowledge units are not whole strings of letters, as postulated in models relying on specific similarity or abstraction, but rather fragments of 2 or 3 letters. Partial memorization of these small units provides a convenient account of the whole pattern of Vokey and Brooks's findings because study items have more units in common with similar than with dissimilar test items, and likewise with grammatical than with ungrammatical ones. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer in artificial grammar learning: A reevaluation.

This article covers methodological and theoretical issues in artificial grammar learning. Arguments that such tasks are mediated by abstract knowledge (e.g., A. S. Reber, see record 1991-00330-001) are based primarily on evidence from transfer experiments, where the surface vocabulary is changed between learning and test items. Because of a number of methodological concerns, the small magnitudes of artificial grammar learning effects generally are difficult to interpret. Possible solutions are offered here. Furthermore, even reliable transfer effects imply neither that subjects have acquired abstract knowledge of the underlying grammar nor that they are performing a process of abstract analogy from memorized whole exemplars. Models that learn only surface fragments of the training stimuli and perform abstraction at test rather than during learning are wholly consistent with transfer phenomena. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dissociations of grammaticality and specific similarity effects in artificial grammar learning.

Three artificial grammar learning experiments investigated the memory processes underlying classification judgments. In Experiment 1, effects of grammaticality, specific item similarity, and chunk frequency were analogous between classification and recognition tasks. In Experiments 2A and 2B, instructions to exclude "old" and "similar" test items, under conditions that limited the role of conscious recollection, dissociated grammaticality and similarity effects in classification. Dividing attention at test also produced a dissociation in Experiment 3. It is concluded that a dual-process model of classification, whereby the grammaticality and specific similarity effects are based mostly on automatic and intentional memory processes, respectively, is consistent with the results, whereas a unitary mechanism account is not. This conclusion is further supported by evidence indicating that chunk frequency had both implicit and explicit influences on classification judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Artificial grammar learning depends on implicit acquisition of both abstract and exemplar-specific information.

The contributions of exemplar-specific and abstract knowledge to artificial grammar learning were examined in amnesic patients and controls. In Experiment 1, grammatical rule adherence and chunk strength exerted separate effects on grammaticality judgments. Amnesic patients exhibited intact classification performance, demonstrating the same pattern of results as controls. In Experiment 2, amnesic patients exhibited impaired declarative memory for chunks. In Experiment 3, both amnesic patients and controls exhibited transfer when tested with a letter set different than the one used for training, although performance was better when the same letter sets were used at training and test. The results suggest that individuals learn both abstract information about training items and exemplar-specific information about chunk strength and that both types of learning occur independently of declarative memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Salience of item knowledge in learning artificial grammars.

Both the specific similarity of test items to study items and the grammaticality of test items were found to be major determinants of performance under task conditions common in the literature. Results bearing on the issue of how item-specific effects are coordinated with knowledge pooled across items are: (1) Better item memory resulted in smaller rather than larger effects of specific similarity on judgments of grammaticality, suggesting that items can be too well differentiated to support transfer to new items. (2) Variation in the effect of specific similarity did not result in compensatory variation in grammaticality, suggesting that any scheme that tightly links the effects of the 2 variables is insufficient. (3) Differential reliance on the 2 knowledge resources was not under good instructional control, which poses a problem for accounts that use functional task analyses to coordinate functionally different memories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transfer in artificial grammar learning: The role of repetition information.

In this article, the authors report 2 experiments that investigated the sources of information used in transfer and nontransfer tasks in artificial grammar learning. Multiple regression analyses indicated that 2 types of information about repeating elements were crucial for performance in both tasks: information about the repetition of adjacent elements and information about repetition of elements in the whole item. Similarity of test items to specific training items and chunk information influenced participants' judgments only in nontransfer tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Associative chunk strength in artificial grammar learning.

In 4 experiments, adherence to grammatical rules and associative chunk strength (including different measures, each calculated on the basis of the frequency with which bigrams and trigrams present in the test strings appeared in the learning strings) were manipulated independently in the test phase of an artificial grammar learning task. When participants learned few items of the grammar (Experiments 1A and 2A), the associated items were more often classified as grammatical than the nonassociated ones. On the other hand, when the learning phase included most of the grammatical items (Experiments 1B and 2B), the only effect observed was an effect of grammaticality. These results suggest that, depending on the specific constraints of the tasks, knowledge based on bigrams and trigrams and knowledge based on the abstraction of the grammatical structure can be used for the classification task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

"Artificial grammar learning depends on implicit acquisition of both abstract and exemplar-specific information": Correction.

Reports an error in the original article by B. J. Knowlton and L. R. Squire (Journal of Experimental Psychology: Learning, Memory, and Cognition, Vol 22[1], 169–181). The Appendix on page 181 contains several errors. The corrected Appendix is provided. (The following abstract of this article originally appeared in record 1996-02680-010). The contributions of exemplar-specific and abstract knowledge to artificial grammar learning were examined in amnesic patients and controls. In Experiment 1, grammatical rule adherence and chunk strength exerted separate effects in grammaticality judgments. Amnesic patients exhibited intact classification performance, demonstrating the same pattern of results as controls. In Experiment 2, amnesic patients exhibited impaired declarative memory for chunks. In Experiment 3, both amnesic patients and controls exhibited transfer when tested with a letter set different than the one used for training, although performance was better when the same letter sets were used at the training and test. The results suggest that individuals learn both abstract information about training items and exemplar-specific information about chunk strength and that both types of learning occur independently of declarative memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Long-term abstract learning of attentional set.

How does past experience influence visual search strategy (i.e., attentional set)? Recent reports have shown that, when given the option to use 1 of 2 attentional sets, observers persist with the set previously required in a training phase. Here, 2 related questions are addressed. First, does the training effect result only from perseveration with the currently active set or from long-term learning? Experiment 1 supported the latter alternative: When training and test were separated by up to 1 week, to prevent perseveration across the 2 sessions, the training effect was still obtained. Second, is the learning feature-specific (tuned to a precise set of colors) or more abstract? Experiments 2 and 3 supported the latter: When stimulus colors were switched between training and test to remove the possibility of feature-specific learning, the training effect again was obtained. These experiments indicate that attentional set is largely guided by long-term abstract learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Phonemic storage of concrete and abstract words with auditory presentation.

Conducted 2 experiments in which Ss' recognition memory for aurally presented concrete and abstract nouns was tested. In Exp I, 56 undergraduates heard study and test lists of 20 concrete and abstract nouns. The test list contained the same 20 nouns plus 20 new nouns which rhymed or did not rhyme with the study stimuli. In Exp II, 56 new undergraduates heard the same lists as in Exp I, but also heard lists in which concrete distractors rhymed with abstract study items and vice versa. Results show that false recognition depends upon the phonemic similarity of distractors to study words, and that the effect is independent of the concreteness of the words or whether the distractor matches the study word in concreteness. While the results may be inconsistent with aspects of the dual process theory of verbal coding, they may indicate that learners use phonemic attributes for recognition when imaginal attributes are insufficient. The appearance of an overall effect of concreteness on false alarms indicates that auditory presentation can produce imagery codes. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The subliminal mere exposure effect does not generalize to structurally related stimuli.

R. F. Bornstein (1994) questioned whether subliminal mere exposure effects might generalize to structurally related stimuli, thereby providing evidence for the existence of implicit learning. Two experiments examined this claim using letter string stimuli constructed according to the rules of an artificial grammar. Experiment 1 demonstrated that brief, masked exposure to grammatical strings impaired recognition but failed to produce a mere exposure effect on novel structurally related strings seen at test. Experiment 2 replicated this result but also demonstrated that a reliable mere exposure effect could be obtained, provided the same grammatical strings were presented at test. The results suggest that the structural relationship between training and test items prevents the mere exposure effect when participants are unaware of the exposure status of stimuli, and therefore provide no evidence for the existence of implicit learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inference and Classification Learning of Abstract Coherent Categories.

Category learning research has primarily focused on how people learn to classify items using simple observable features. However, classification is only 1 way to learn categories. In addition, many concepts have an underlying coherence that explains the featural similarity among exemplars, such as abstract coherent concepts whose instances differ greatly on their observable features. In 3 experiments, the authors investigated how abstract coherent categories are acquired through 2 common means of category learning, classification and inference. Because inference promotes more focus on within-category information than does classification, they hypothesized that inference learning would lead to a better understanding of the underlying coherence of abstract coherent categories. All 3 experiments support this prediction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Gender and reporting differences in measures of depression.

135 female and 75 male undergraduates (aged 18–30 yrs) responded to the Beck Depression Inventory and to 9 items assessing depression from the Hopkins Symptom Checklist. The hypothesis was explored that males particularly would endorse test items in a less "depressed" direction when presented explicitly as constituting a test of depression, but would endorse more depressive content when items were presented in a context not portrayed as measuring depression. Some support was obtained for the view that males may approach and respond differently to depression inventories compared to females. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Similarity-Guided Depth of Retrieval: Constraining at the Front End.

Lee Brooks has done important work to show that categorization often reflects reliance on specific instances rather than on an abstract representation. His work on the advantages of using a diagnostic hypothesis to search medical stimuli has demonstrated how constraining what one looks for influences clinical reasoning. Similarly, cognitive control can be accomplished by constraining memory retrieval in ways that influence interpretation of a memory probe. Here, we report two experiments in which the similarity of study items constrained how test items were interrogated for an immediate memory test and thereby produced differences in the depth of retrieval. A novel procedure that tests foil memory was used to diagnose differences in similarity-guided retrieval depth. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of proportion overlap and repeated testing on primed word fragment completion.

Extended the idea of a proportion overlap (PPO) effect in perceptual identification to a word fragment completion (WFC) test of implicit memory. 80 university students studied a list of words (e.g., cheetah) and received an implicit WFC test (e.g., complete -h--t-h). On the test, the ratio of studied to nonstudied items (PPO) was 0, 25, 50, 75, or 100%. Ss were administered the identical test twice. PPO did not affect priming in WFC, on either the 1st or 2nd test. Also, the completion of studied and nonstudied fragments increased over repeated tests, but priming (the studied–nonstudied rate) remained unchanged. The PPO of items between study and test does not affect performance on primed WFC. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalization hypothesis of abstract-concept learning: Learning strategies and related issues in Macaca mulatta, Cebus apella, and Columba livia.

The generalization hypothesis of abstract-concept learning was tested with a meta-analysis of rhesus monkeys (Macaca mulatta), capuchin monkeys (Cebus apella), and pigeons (Columba livia) learning a same/different (S/D) task with expanding training sets. The generalization hypothesis states that as the number of training items increases, generalization from the training pairs will increase and could explain the subjects' accurate novel-stimulus transfer. By contrast, concept learning is learning the relationship between each pair of items; with more training items subjects learn more exemplars of the rule and transfer better. Having to learn the stimulus pairs (the generalization hypothesis) would require more training as the set size increases, whereas learning the concept might require less training because subjects would be learning an abstract rule. The results strongly support concept or rule learning despite severely relaxing the generalization-hypothesis parameters. Thus, generalization was not a factor in the transfer from these experiments, adding to the evidence that these subjects were learning the S/D abstract concept. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Chunks are not enough: The insufficiency of feature frequency-based explanations of artificial grammar learning.

Two experiments with a total of 104 undergraduates tested chunk frequency explanations of artificial grammar learning, which hold that classification performance is dependent on some metric derived from the frequency with which certain features occur within the letter string stimuli. Exp 1 revealed that classification performance was affected by close graphemic similarity between specific training (e.g., MXRVXT) and test strings (e.g., MXRMXT), despite the fact that similar strings did not contain frequently occurring features (e.g., bigrams or trigrams). This effect was replicated in Exp 2a, and Exp 2b demonstrated that substituting letters to make the consonant strings pronounceable (e.g., substituting X, R, and T, in the consonant string MXRMXT with Y, A, I, to produce MYAMYI) affected classification performance, despite the fact that objective measures of feature frequency were not altered. It is argued that models of classification that focus entirely on the frequency of features within the literal stimulus are insufficient, and that some allowance must be made for how the stimulus is encoded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A comparison of responses of Canadian and English children on the Junior Eysenck Personality Questionnaire.

The Junior Eysenck Personality Questionnaire was administered to 1,058 7–15 yr old Canadians. Factor patterns of the test items were compared with those reported for British children. Results of factor analyses confirmed a strong similarity between the Canadian and British samples in the loadings of most items on Psychoticism, Extraversion, Neuroticism, and Social Desirability. Factor comparisons were high and reliabilities satisfactory. Comparison of mean scores for the Canadian and British samples revealed, for the former, higher scores on Psychoticism and Neuroticism and lower scores on Social Desirability. (French abstract) (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)