Effects of concurrent load on feature- and rule-based generalization in human contingency learning.

The effect of concurrent load on generalization performance in human contingency learning was examined in 2 experiments that employed the combined positive and negative patterning procedure of Shanks and Darby (1998). In Experiment 1, we tested 32 undergraduates and found that participants who were trained and tested under full attention showed generalization consistent with the application of an opposites rule (i.e., single cues signal the opposite outcome to their compound), whereas participants trained and tested under a concurrent cognitive load showed generalization consistent with surface similarity. In Experiment 2, we replicated the effect with 148 undergraduates and provided evidence that it was the presence of concurrent load during training, rather than during testing, that was critical. Implications for associative, inferential, and dual-process accounts of human learning are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Hypotheses and habits in verbal "operant conditioning.'

The traditional explanation of experiments related to conditioning of verbal behavior in terms of operant conditioning, i.e., learning without awareness, was questioned. It was hypothesized that such conditioning to cues given by E might be based on S's awareness of the cue and assumed meaning of such a stimulus. 2 experiments were performed, 1 where plural nouns were reinforced, and a 2nd to test the generalization of this acquired pattern on a word association test. The usual findings re: conditioning of plural nouns was replicated and there seemed to be a carry-over of the set to the word association test. However, some Ss seemed to be aware of the meaning of such a reinforcer as "um-hm." Moreover, response set was also seen to affect conditionability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit learning and generalization of the "mere exposure" effect.

Reports 2 experiments that examined the generalization of the "mere exposure" effect. Both experiments demonstrated that positive affect, produced by repeated viewing of a set of stimuli, generalizes to previously unseen stimuli that are similar to the exposed stimuli along certain abstract dimensions. Exp I, with 82 Ss, used letter strings constructed according to a complex rule system. Positive affect attributable to exposure generalized to novel letter strings that obeyed the rule system. Affective generalization was related to Ss' judgments of whether the novel strings obeyed the rule system. Exp II (40 Ss), in which the stimuli were complex visual patterns created by distorting standard forms, yielded an orderly gradient of affective generalization to novel patterns at varying levels of distortion. Results indicate that the exposure effect behaves in a manner similar to "implicit" concept learning and rule induction. The generalization techniques developed here provide a novel method for studying the affective processing of stimuli. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus selection and irrelevant stimuli in discrimination learning by pigeons.

Studied discrimination learning in 2 experiments with 32 and 16 White Carneaux pigeons. Exp. I confirmed that Ss trained in a free-operant situation produce a sharper gradient of generalization around a specific irrelevant stimulus if they are given true discrimination (TD) training than if given pseudodiscrimination (PD) training. An additional pair of groups, however, showed that this difference could be eliminated if, after initial training but before the test for generalization, both TD and PD Ss were given TD training on an entirely independent set of stimuli. This suggests that the normally flat PD gradient may represent a test effect: control by the specific irrelevant stimulus is masked by other more powerful irrelevant stimuli that are only suppressed by TD training. Exp. II demonstrated that in a discrete-trial situation, PD training results in a sharper gradient than does TD training, suggesting that the other unidentified irrelevant stimuli are present only in free-operant situations. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intentional Control and Implicit Sequence Learning.

Sequence knowledge acquired by repeated exposure to targets in a speeded localization task was studied in 3 experiments that sought to test A. Destrebecqz and A. Cleeremans's (2001, 2003) claim that, under certain circumstances, the expression of such sequence knowledge cannot be brought under intentional control. In Experiment 1 participants were trained on either a deterministic or a probabilistic sequence and then performed a free-generation test under either inclusion or exclusion instructions. Participants were found to be capable of both expressing (inclusion) and avoiding expressing (exclusion) sequence knowledge. These results were confirmed in Experiment 2 with a more exact replication of Destrebecqz and Cleeremans's methodology. In Experiment 3 participants performed a trial-by-trial generation test under both inclusion and exclusion conditions after a much longer period of training. All the findings are consistent with the proposal that information acquired during sequence learning is explicit in nature. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generalizing linguistic structures under high attention demands.

We explored whether the generalization of rules based on simple structures depends on attention. Participants were exposed to a stream of artificial words that followed a simple syllabic structure (ABA or AAB), overlaid on a sequence of familiar noises. After passively listening, participants successfully recognized the individual words present in the stream among foils, and they were able to generalize the underlying word structure to new exemplars. Yet, when attention was diverted from the speech stream (by requiring participants to monitor the sequence of noises), recognition of the individual words fell dramatically irrespective of word structure, whereas generalization depended on stimulus structure. For structures based on vowel repetitions across nonadjacent syllables (ABA; Experiment 1), generalization was affected by attention. In contrast, for structures based on adjacent repetitions (AAB; Experiment 2), generalization capacity was unaffected by attention. This pattern of results was replicated under favorable conditions for generalization, such as increased token variability and the implementation of the rule over whole syllables (Experiments 3 and 4). These results suggest a differential effect of attention on rule learning and generalization depending on stimulus structure. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The influence of consistency, frequency, and semantics on learning to read: An artificial orthography paradigm.

Two experiments explored learning, generalization, and the influence of semantics on orthographic processing in an artificial language. In Experiment 1, 16 adults learned to read 36 novel words written in novel characters. Posttraining, participants discriminated trained from untrained items and generalized to novel items, demonstrating extraction of individual character sounds. Frequency and consistency effects in learning and generalization showed that participants were sensitive to the statistics of their learning environment. In Experiment 2, 32 participants were preexposed to the sounds of all items (lexical phonology) and to novel definitions for half of these items (semantics). Preexposure to either lexical phonology or semantics boosted the early stages of orthographic learning relative to Experiment 1. By the end of training, facilitation was restricted to the semantic condition and to items containing low-frequency inconsistent vowels. Preexposure reduced generalization, suggesting that enhanced item-specific learning was achieved at the expense of character-sound abstraction. The authors' novel paradigm provides a new tool to explore orthographic learning. Although the present findings support the idea that semantic knowledge supports word reading processes, they also suggest that item-specific phonological knowledge is important in the early stages of learning to read. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attitude Formation Through Exploration: Valence Asymmetries.

The formation of attitudes toward novel objects was examined as a function of exploratory behavior. An initial experiment, in which participants played a computer game that required them to learn which stimuli, when sampled, produced favorable or unfavorable outcomes, demonstrated learning, attitude formation, and generalization to novel objects. The findings also revealed 2 interesting valence asymmetries: a learning asymmetry involving better learning for negatively valenced than positively valenced objects and a generalization asymmetry involving stronger generalization as a function of negative than of positive attitudes. Findings from 4 experiments led to an explanation of the learning asymmetry in terms of information gain being contingent on approach behavior and related the generalization asymmetry to a negativity bias that weighs resemblance to a known negative more heavily than resemblance to a positive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus control of shuttle avoidance in young and adult rats.

Investigated stimulus generalization of 2-way active avoidance behavior in young and adult rats. In Exp. I with 12 adult and 12 young male Holtzman albino rats, CS frequency gained marked and comparable control over responding in both age groups; variation of background frequency prior to a no-tone CS, however, failed to exert any substantial control over avoidance behavior in either age group. In Exp. II with 12 Ss, Pavlovian frequency discrimination training was interpolated between acquisition of the shuttle response and generalization testing. Relative to their respective single stimulus control groups, the adult Ss showed a reliable peak shift in modal responding and the young Ss revealed a distortion in the gradient at frequency values on the side of CS+, opposite that of CS-. Although the occurrence of a peak shift was somewhat surprising in light of the fact that CS- here served as a "safety" signal, the data are interpreted as consistent with explanations of discrimination learning based upon the summation of excitatory and inhibitory gradients. In general, both experiments suggest that variations of CS frequency in an active avoidance situation tends to result in similar gradients for both young and adult Ss. The disparity between the present and previous findings are discussed in terms of the response requirements of the test situation. (French summary) (23 ref.) (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)     

The experimental task influences cue competition in human causal learning.

Participants were shown A+ and C- trials followed by AB+ and CD+ trials. These trials were embedded in a causal learning task in which participants had to learn either the relationship between different foods and allergic reactions or the relationship between different stocks and an increase in the stock market index. The authors orthogonally varied the manner in which the different cues were presented to participants during training. Cue competition was related to the causal learning scenario but not to the manner in which the different cues were presented. These results question claims of a human bias toward configural processing that were based on difficulties in finding cue competition in some previous causal learning experiments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metamemory judgments and the benefits of repeated study: Improving recall predictions through the activation of appropriate knowledge.

Correspondence between judgments of learning (JOLs) and actual recall tends to be poor when the same items are studied and recalled multiple times (e.g., A. Koriat, L. Sheffer, & H. Ma’ayan, 2002). The authors investigated whether making relevant metamemory knowledge more salient would improve the association between actual and predicted recall as a function of repeated exposure to the same study list. In 2 experiments, participants completed 4 study–recall phases involving the same list of items. In addition to having participants make item-by-item JOLs during each study phase, after the 1st study–recall phase participants also generated change-in-recall estimates as to how many more or fewer words they would recall given another exposure to the same study list. This estimation procedure was designed to highlight repeated study as a factor that can contribute to recall performance. Activating metamemory knowledge about the benefits of repeated study for recall in this way allowed participants to accurately express this knowledge in a free-recall context (Experiment 2), but less so when the memory test was cued recall (Experiment 1). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Feature- and rule-based generalization in human associative learning.

Two experiments examined the contributions of feature- and rule-based knowledge in a human associative learning task. Participants were presented with concurrent negative (A?→?O, B?→?O, AB?→?no O) and positive (C?→?no O, D?→?no O, CD?→?O) patterning problems in which certain combinations of foods were associated with an allergy outcome (O). In the test stage, some participants showed normal feature-based generalization to novel trial types, whereas other participants transferred the patterning rule (i.e., a compound and its elements signal opposite outcomes). Mastery of the discrimination presented in the training phase was strongly linked to rule-based generalization. The results suggest that models of human associative learning need to incorporate mechanisms for rule-based as well as for feature-based generalization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A stability bias in human memory: Overestimating remembering and underestimating learning.

The dynamics of human memory are complex and often unintuitive, but certain features—such as the fact that studying results in learning—seem like common knowledge. In 12 experiments, however, participants who were told they would be allowed to study a list of word pairs between 1 and 4 times and then take a cued-recall test predicted little or no learning across trials, notwithstanding their large increases in actual learning. When queried directly, the participants espoused the belief that studying results in learning, but they showed little evidence of that belief in the actual task. These findings, when combined with A. Koriat, R. A. Bjork, L. Sheffer, and S. K. Bar’s (2004) research on judgments of forgetting, suggest a stability bias in human memory—that is, a tendency to assume that the accessibility of one’s memories will remain relatively stable over time rather than benefiting from future learning or suffering from future forgetting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stress affects the selection of relevant from irrelevant stimuli.

Two experiments were used to examine the effects of stress on latent inhibition (LI; poorer learning with a previously exposed irrelevant stimulus rather than a novel stimulus). In Experiment 1, stress was induced in college students by threatening participants' self-esteem with a difficult number series completion test that was related to intelligence. In Experiment 2, the participants were job seekers who were either informed or not that the LI test was part of the selection process. In both experiments, LI was attenuated in high- as compared with low-stressed participants. The results suggest that stress and/or anxiety impairs the inhibition of irrelevant-preexposed stimuli. Implications for understanding the impaired selective attentional processes in schizophrenia and schizotypy are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inferring category characteristics from sample characteristics: Inductive reasoning and social projection.

Inductive reasoning involves generalization from sample observations to categories. This research examined the conditions under which generalizations go beyond the boundaries of the sampled categories. In Experiment 1, participants sampled colored chips from urns. When categorization was not salient, participants revised their estimates of the probability of a particular color even in urns they had not sampled. As categorization became more salient, generalization became limited to the sampled urn. In Experiment 2 the salience of categorization in social induction was varied. When social categorization was not salient, participants projected their own responses to test items to members of a laboratory group even when they themselves did to belong to this group. When salience increased, projection decreased among nonmembers but not among members. In Experiment 3 these results were replicated in a field setting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Rules and exemplars in category learning

Psychological theories of categorization generally focus on either rule- or exemplar-based explanations. We present 2 experiments that show evidence of both rule induction and exemplar encoding as well as a connectionist model, ATRIUM, that specifies a mechanism for combining rule- and exemplar-based representation. In 2 experiments participants learned to classify items, most of which followed a simple rule, although there were a few frequently occurring exceptions. Experiment 1 examined how people extrapolate beyond the range of training. Experiment 2 examined the effect of instance frequency on generalization. Categorization behavior was well described by the model, in which exemplar representation is used for both rule and exception processing. A key element in correctly modeling these results was capturing the interaction between the rule- and exemplar-based representations by using shifts of attention between rules and exemplars.     

Overt attention and predictiveness in human contingency learning.

Two experiments used eye-tracking procedures to investigate the relationship between attention and associative learning in human participants. These experiments found greater overt attention to cues experienced as predictive of the outcomes with which they were paired, than to cues experienced as nonpredictive. Moreover, this attentional bias persisted into a second training phase when all cues were equally predictive of the outcomes with which they were paired, and it was accompanied by a related bias in the rate of learning about these cues. These findings are consistent with the attentional model of associative learning proposed by Mackintosh (1975), but not with that proposed by Pearce and Hall (1980). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Beyond dissociation logic: Evidence for controlled and automatic influences in artificial grammar learning.

Evidence for unconscious learning has typically been based on dissociations between direct and indirect tests of learning. Because of some inherent problems with dissociation logic, we applied the logic of opposition to 2 artificial grammar learning experiments. In Experiment 1, participants were exposed to 2 different sets of letter strings, generated from 2 different grammars, and later rated test strings for grammaticality with either in-concert (rate grammatical strings consistent with either structure) or opposition (rate grammatical only strings from 1 of the structures) instructions. Manipulating response deadline affected controlled, but not automatic influences. In Experiment 2, after similar training, a source-monitoring test was administered from which the in-concert and opposition conditions were derived. The test indicated that varying the retention interval affected controlled, but not automatic, influences. The results are discussed in terms of awareness, knowledge representation, and metacognitive processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)