A precursor to the relational evaluation procedure: searching for the contextual cues that control equivalence responding.

The precursor to the relational evaluation procedure (pREP) is a go/no-go successive discrimination procedure for examining stimulus equivalence. Previous research has shown that it does not readily produce equivalence responding unless some matching-to-sample (MTS) procedures are incorporated into the experimental sequence. Two experiments attempted to identify contextual cues that would generate equivalence responding on the pREP. Experiment 1 examined the effects of using abstract symbols or various verbal labels as response options on the pREP. Only the words same and different, when used as response options, reliably produced equivalence responding across 4 subjects. Experiment 2 examined different pretraining preparations designed to attach the functions of the words same and different to abstract symbols that could then be used as response options on the pREP. The most effective pretraining procedure involved multiple-exemplar training during which subjects were trained to respond to abstract symbols in the presence of pairs of stimuli that were either formally the same or different. The abstract symbols were subsequently used as response options with the pREP, and all subjects reliably demonstrated equivalence responding. The findings suggest that the relations of same and different may be fundamental to equivalence responding. These findings are discussed in terms of what they suggest about the nature of the equivalence phenomenon specifically and derived relational responding more generally.     

Does subliminal priming of free response choices depend on task set or automatic response activation?

In a task requiring speeded bidirectional responses to arrow symbols (?,?), "free choice" responses to interspersed bidirectional stimuli (<>) are influenced by masked directional primes (e.g., Schlaghecken & Eimer, 2004). By varying stimulus-response (S-R) compatibility, we tested whether this priming effect is mediated by the conscious instructional set, or instead by pre-existing directional associations to the symbols. In two experiments, one group of participants was instructed to respond with the hand consistent with the implied direction of the arrow symbols, while another group was instructed to make the spatially opposite responses. Both groups showed priming of "free choice" responses. However, such priming was always biased according to the instructional set rather than pre-existing associations. Subliminal priming of "free choice" responses therefore depends on conscious task goals.     

Pitches that Wire Together Fire Together: Scale Degree Associations Across Time Predict Melodic Expectations

The ongoing generation of expectations is fundamental to listeners’ experience of music, but research into types of statistical information that listeners extract from musical melodies has tended to emphasize transition probabilities and n-grams, with limited consideration given to other types of statistical learning that may be relevant. Temporal associations between scale degrees represent a different type of information present in musical melodies that can be learned from musical corpora using expectation networks, a computationally simple method based on activation and decay. Expectation networks infer the expectation of encountering one scale degree followed in the near (but not necessarily immediate) future by another given scale degree, with previous work suggesting that scale degree associations learned by expectation networks better predict listener ratings of pitch similarity than transition probabilities. The current work outlines how these learned scale degree associations can be combined to predict melodic continuations and tests the resulting predictions on a dataset of listener responses to a musical cloze task previously used to compare two other models of melodic expectation, a variable-order Markov model (IDyOM) and Temperley's music-theoretically motivated model. Under multinomial logistic regression, all three models explain significant unique variance in human melodic expectations, with coefficient estimates highest for expectation networks. These results suggest that generalized scale degree associations informed by both adjacent and nonadjacent relationships between melodic notes influence listeners’ melodic predictions above and beyond n-gram context, highlighting the need to consider a broader range of statistical learning processes that may underlie listeners’ expectations for upcoming musical events.     

The contextually controlled, feature-mediated classification of symbols

The classification of names of people or objects based on the features acquired by the names and the sorting instructions provided is a commonplace occurrence. For example, given the names Renoir, Pollock, James and Voltaire the average adult would be able to classify them differentially based on the instruction to classify them based on vocation or nationality. In general, such a repertoire reflects the reclassification of symbols (i.e, the names of individuals) in terms of contextual cues (instructions to sort by vocation or nationality) and the features acquired by the symbols (the specific nationalities and vocations). The present experiment studied this phenomenon with the use of arbitrary stimuli that did not have clear preexperimental associations. Two of 4 participants classified the symbols into different equivalence classes based on the prevailing contextual cues and the features that had been acquired by the symbols. Using an ABA reversal design we then demonstrated that 1 participant classified the symbols in accordance with the contextual cues and acquired features when present, but not in the absence of the contextual cues. A 3rd participant showed symbol classification that differed from that predicted by the procedures, and the 4th classified the symbols based on one set of features but not on context. These data describe one set of conditions that could account for the establishment of complex classification repertoires that occur in natural settings.     

Modality-specific repetition priming of auditory word recognition

Subjects were pretrained on 30 experimental words by matching each to one of three definitions. The pretrained words were presented auditorily, or in their conventional spellings, or phonically misspelt (e.g., LORNE for lawn). The same words were later interleaved randomly with 70 new filler words and presented auditorily in a background of white noise. Only the auditory pretraining led to significantly improved recognition of the experimental words when compared with the recognition scores of a control group of subjects given no form of pretraining.     

Blocking with serial compound stimuli: The role of local context and second-order associations

Blocking was studied with rats in two serial conditioning experiments in which CS1 was followed by CS2 and then shock. Experiment 1 demonstrated that pretraining with CS1 was able to block conditioning to CS2 when the pretraining consisted of trace conditioning. But when serial conditioning was used for pretraining, with a third stimulus as the second element of the compound, then blocking was not detected during the subsequent phase. In Experiment 2 the effect of pretraining with CS2 on blocking with CS1 was examined. Blocking was effective, but only when steps were taken to minimize the growth of second-order associations resulting from the pairing of CS1 with CS2. These results are consistent with a principle stating that the ability of a pretrained stimulus to block the added stimulus in a compound depends on the relative contiguity of each stimulus to the US.     

Context Specificity of Excitation and Inhibition in Ambiguous Stimuli

Two experiments examined the susceptibility of excitation and inhibition to contextual change when the conditioned stimulus (CS) was ambiguous using an appetitive conditioning paradigm. In Experiment 1, excitation to a CS was lost with a context switch when inhibition had been learned to the CS in a prior feature-negative (FN) discrimination. Control groups that had received either more or less excitatory conditioning in the absence of inhibitory pretraining showed no loss. In Experiment 2 inhibition was lost with a context switch in a group that had received excitatory and then inhibitory conditioning with the CS. No loss was observed in a group that had not received excitatory pretraining. The results suggest that contexts are especially likely to control performance to ambiguous CSs when they can modulate the second of two learned associations. Results are discussed in terms of their implications for occasion setting and modern conditioning theory.     

The effects of type and amount of pretraining on transfer in concept formation

Two experiments were conducted to investigate the effects of 2 types of directed attention pretraining, a form of stimulus predifferentiation, on immediate- and delayed-transfer tasks in concept identification. In both experiments, the participants received either the "seeing-and-discriminating" or "seeing" technique of pretraining, except for those assigned to the control group. The participants received different amounts of pretraining. In the first experiment, participants were required to learn new concepts from the same category for the delayed-transfer task, whereas in the second experiment, the delayed-transfer task involved concepts from a different category. Among the major findings in both experiments are that the pretraining methods resulted in positive transfer on all transfer tasks. In general, the seeing-and-discriminating method yielded a more positive transfer than the seeing technique. Maximal positive transfer effects were found with a small number of trials. The implications of the findings for understanding the effectiveness of various training methods used for problem solving are discussed.     

Formation of taste aversions in rats following prior exposure to sickness

Findings from the present experiments extend those of earlier studies and show that rats form weaker conditioned taste aversions if they are exposed to a sickness-inducing agent prior to a single training trial. The present experiments appear to rule out the possible confounding factors that, during pretraining, (1) animals became addicted to the drugs that were intended to induce sickness during training, (2) drug tolerances were created and hence reduced the effectiveness of the same or different sickness-inducing agents used to induce sickness during training, or (3) associations between other stimuli and sickness were formed and interfered with or blocked the formation of subsequent taste aversions. It was concluded that the associative capacity of sickness can be reduced through pre-exposure.     

A different recruitment of the lateral and basolateral amygdala promotes contextual or elemental conditioned association in Pavlovian fear conditioning

Convergent data suggest dissociated roles for the lateral (LA) and basolateral (BLA) amygdaloid nuclei in fear conditioning, depending on whether a discrete conditioned stimulus (CS)-unconditional stimulus (US) or context-US association is considered. Here, we show that pretraining inactivation of the BLA selectively impaired conditioning to context. In contrast, inactivation of the LA disrupted conditioning to the discrete tone CS, but also either impaired or enhanced contextual conditioning, depending on whether the context was in the foreground or in the background. Hence, these findings refine the current model of the amygdala function in emotional learning by showing that the BLA and the LA not only differentially contribute to elemental and context-US association, but also promote, through their interaction, the most relevant of these two associations.     

The effect of the temporal locus of the introtact probe on the hypothesis-testing strategies of kindergarten children

The hypothesis-testing behavior of kindergarten children in discrimination learning was studied in a factorial design with two temporal placements of introtact probes (pretrial and posttrial) and two types of pretraining (unidimensional and multidimensional). Pretrial probes consisting of a request for the child's current hypothesis were administered in a conventional manner at the beginning of each trial with the stimuli in view and prior to the choice response. Posttrial probes were administered also with the stimuli in view, but after the choice response had occurred and feedback information had been provided. Learning-to-learn experience in solving three pretraining problems was given either with unidimensional simultaneous problems or with more complex multidimensional problems like the criterion tasks. The results indicated that posttrial probes produced superior local consistency, win-stay, and lose-shift probabilities, relative to pretrial probes, for both types of pretraining. Posttrial probes, however, facilitated learning and the testing of valid hypotheses only for multidimensional pretraining. These results are consistent with the hypothesis that posttrial probes constrain the child to be locally consistent and therefore improve short-term efficiency in hypothesis testing under both pretraining conditions. However, posttrial probes produce an improvement in long-term efficiency, and therefore in learning, only when other components of a successful strategy are acquired as in multidimensional pretraining.     

Enhancing challenged students' recognition of mathematical relations through differential outcomes training

Previous studies have reported that the differential outcomes procedure enhances learning and memory in special populations with cognitive deficits (see Goeters, Blakely, & Poling, 1992, for a review). In the present study we extend these findings to healthy adults who were asked to discriminate between the symbols " > " and " < " in mathematical statements. In Experiment 1, the performance of participants who showed difficulties in discriminating between these symbols was better (shorter response times) for the differential outcomes condition than for the nondifferential outcomes condition. In Experiment 2, the difficulty of the task was increased by using signed decimal numbers. Similar to Experiment 1, participants who initially had difficulties in discriminating between the symbols showed better performance (higher accuracy) for the differential outcomes condition than for the nondifferential outcomes condition, but only when both numbers were negative. These findings suggest that the differential outcomes procedure can be used to improve performance of challenged healthy adults on discrimination tasks with mathematical symbols and relations.     

Forward and backward blocking of causal judgment is enhanced by additivity of effect magnitude

When two causes for a given effect are simultaneously presented, it is natural to expect an effect of greater magnitude. However many laboratory tasks preclude such an additivity rule by imposing a ceiling on effect magnitude-for example, by using a binary outcome. Under these conditions, a compound of two causal cues cannot be distinguished from a compound of one causal cue and one noncausal cue. Two experiments tested the effect of additivity on cue competition. Significant but weak forward blocking and no backward blocking were observed in a conventional "allergy" causal judgment task. Explicit pretraining of magnitude additivity produced strong and significant forward and backward blocking. Additivity pretraining was found to be unnecessary for another cue competition effect, release from overshadowing, which does not logically depend on additivity. The results confirm that blocking is constrained when effect magnitude is constrained and provide support for an inferential account of cue competition.     

The problem-solving strategies of kindergarten and first-grade children during discrimination learning

Kindergarten and first-grade children (6 and 7 years of age, respectively) were given specially designed discrimination tasks with introtact probes preceding each trial. One group (CON) was given the criterion task without prior training. A second group (LTL) received three pretraining tasks of the same type as the criterion task. A third group (HYP) received the same pretraining tasks, but with explicit instructions designed to teach a simple hypothesis-testing strategy. Several indices, designed to reflect the use of win-stay and lose-shift rules, as well as memory for disconfirmed hypotheses, were computed from the protocols of the criterion task. The indices for Group CON suggested that most of these children were using a guessing strategy that involved quite frequent changes in hypotheses. Moreover, many of these children restricted their hypotheses to the irrelevant cues. The indices for Group LTL revealed a spontaneous use of the hypothesis-testing strategy by nearly half of the children. The results for Group HYP indicated that over four-fifths of these children became highly efficient in the use of the problem-solving strategy.     

A visualization technique for Bayesian reasoning

We tested a method for solving Bayesian reasoning problems in terms of spatial relations as opposed to mathematical equations. Participants completed Bayesian problems in which they were given a prior probability and two conditional probabilities and were asked to report the posterior odds. After a pretraining phase in which participants completed problems with no instruction or external support, participants watched a video describing a visualization technique that used the length of bars to represent the probabilities provided in the problem. Participants then completed more problems with a chance to implement the technique by clicking interactive bars on the computer screen. Performance improved dramatically from the pretraining phase to the interactive‐bar phase. Participants maintained improved performance in transfer phases in which they were required to implement the visualization technique with either pencil‐and‐paper or no external medium. Accuracy levels for participants using the visualization technique were very similar to participants trained to solve the Bayes theorem equation. The results showed no evidence of learning across problems in the pretraining phase or for control participants who did not receive training, so the improved performance of participants using the visualization method could be uniquely attributed to the method itself. A classroom sample demonstrated that these benefits extend to instructional settings. The results show that people can quickly learn to perform Bayesian reasoning without using mathematical equations. We discuss ways that a spatial solution method can enhance classroom instruction on Bayesian inference and help students apply Bayesian reasoning in everyday settings.     

Disentangling the Mechanisms of Symbolic Number Processing in Adults’ Mathematics and Arithmetic Achievement

A growing body of research has shown that symbolic number processing relates to individual differences in mathematics. However, it remains unclear which mechanisms of symbolic number processing are crucial—accessing underlying magnitude representation of symbols (i.e., symbol‐magnitude associations), processing relative order of symbols (i.e., symbol‐symbol associations), or processing of symbols per se. To address this question, in this study adult participants performed a dots‐number word matching task—thought to be a measure of symbol‐magnitude associations (numerical magnitude processing)—a numeral‐ordering task that focuses on symbol‐symbol associations (numerical order processing), and a digit‐number word matching task targeting symbolic processing per se. Results showed that both numerical magnitude and order processing were uniquely related to arithmetic achievement, beyond the effects of domain‐general factors (intellectual ability, working memory, inhibitory control, and non‐numerical ordering). Importantly, results were different when a general measure of mathematics achievement was considered. Those mechanisms of symbolic number processing did not contribute to math achievement. Furthermore, a path analysis revealed that numerical magnitude and order processing might draw on a common mechanism. Each process explained a portion of the relation of the other with arithmetic (but not with a general measure of math achievement). These findings are consistent with the notion that adults’ arithmetic skills build upon symbol‐magnitude associations, and they highlight the effects that different math measures have in the study of numerical cognition.     

Judgments of learning and improvement

Can learners accurately judge the rate of their learning? Rates of learning may be informative when study time is allocated across materials, and students' judgments of their learning rate have been proposed as a possible metacognitive tool. Participants estimated how much they improved between presentations in multitrial learning situations in which n-gram paragraphs (in Experiments 1 and 2) or word pairs (Experiments 3 and 4) were learned . In the first experiment, participants rated improvement on a percentage scale, whereas on the second and third, judgments were given on a 0–6 scale. Experiment 4 used both a percentage scale and an absolute number scale. The main result was that judgments of improvement were poorly correlated with actual improvement and, in one case, were negatively correlated. Although judgments of improvement were correlated with changes in judgments of learning, they were not reliable indicators of actual improvement. Implications are discussed for theoretical work on metacognition.     

Element pretraining influences the content of appetitive serial compound conditioning in rats

Four experiments with rat subjects in a Pavlovian appetitive conditioning procedure examined the effects of prior pairings of S2 with the unconditioned stimulus (US) on the nature of the associations formed in S1----S2----US serial compound conditioning. Experiments 1 and 2 showed that prior training of S2 prevented the acquisition of stimulus-stimulus (S-S) associations between S1 and stimulus features of S2, but enhanced the acquisition of stimulus-response (S-R) associations between S1 and the emotional conditioned response (CR) evoked by S2. Experiments 3 and 4 showed that the effects of S2 pretraining were not due to S2 training itself, but rather to its endowing S2 with the ability to evoke a strong CR during the early stages of serial compound conditioning. In Experiment 3, suppression of the CR to a pretrained S2 during serial compound conditioning permitted the establishment of S-S associations. In Experiment 4, the induction of a CR in the presence of an untrained S2 during serial compound conditioning prevented the acquisition of S-S associations. Implications of these data for our understanding of compound conditioning are discussed.