Attentional perspectives on context-dependence of information retrieval

Attention has been traditionally understood as an important factor on acquiring new information. A review of the literature suggests that attention, specifically attention to the contexts, also plays a relevant role on information retrieval. It also shows that attention to the contexts is modulated by the ambiguity of the situation, and the informative value contexts have. The virtues and limitations of different attentional theories of learning applied to the explanation of the effects of context change on retrieval of the information are discussed. This analysis uncovers the weaknesses of current research on context processing that should be corrected by future research: The need of independent measures of attention to the contexts, the evaluation of the mechanisms of contextual control, and the possibility of taking an evolutionary perspective on the effects of context change (AU)

No disponible

Differentiating models of associative learning: reorientation, superconditioning, and the role of inhibition.

A recent associative model (Miller, N.Y., & Shettleworth, S.J., 2007. Learning about environmental geometry: An associative model. Journal of Experimental Psychology: Animal Behavior Processes B, 33, 191-212) is an influential mathematical account of how agents behave when reorienting to previously learned locations in spatial arenas. However, it is mathematically and empirically flawed. The current article explores these flaws, including its inability to properly predict geometric superconditioning. We trace the flaws to the model's mathematical structure and how it handles inhibition. We then propose an operant artificial neural network model that solves these problems with inhibition and can correctly model both reorientation and superconditioning.

Stimulus-classification traces are dominant in response learning.

Priming can reflect the stimulus-driven retrieval of output-related memory traces, commonly referred to as stimulus-response associations. The purpose of the current study was to investigate which aspects of the output exactly are preserved in these traces using electroencephalography (EEG). We orthogonally manipulated the repetition of action and classification whilst participants performed one of the two semantic tasks according to the cue. We found no evidence of stimulus-action associations but significant effects relevant to the retrieval of stimulus-classification associations in participants' accuracy and RT. Event-related potential (ERP) and oscillatory analysis further revealed a classification-related modulation at around 200 ms after stimulus onset, which appeared much earlier than the one reported in previous studies. These classification effects possibly indicate the modification of memory traces which requires the dynamic interaction of temporal and frontal cortices. The finding of classification effects across behavioural and EEG data suggested that the formation of stimulus-classification traces is rather spontaneous and may be dominant in single trial stimulus-response binding.

Efecto del intervalo entre estímulos sobre la adquisición y manifestación de aprendizaje asociativo con estímulos enmascarados / Effect of interstimulus interval on acquisition and expression of associative learning with masked stimuli

El objetivo de este trabajo era estudiar el efecto del intervalo entre estímulos (IEE) sobre el aprendizaje asociativo con estímulos enmascarados. Ochenta y cuatro participantes recibieron presentaciones repetidas de dos secuencias de estímulos (E1A E2A y E1B E2B), siendo E1 un estímulo enmascarado y E2 un estímulo imperativo para una tarea de tiempo de reacción (TR). El IEE era de 23 ms para la mitad de los sujetos y 305 ms para la otra mitad. Posteriormente, todos los sujetos fueron probados con 14 presentaciones de secuencias compatibles (E1A E2A y E1B E2B) y otras 14 incompatibles (E1A E2B y E1B E2A), utilizando un IEE de 23 ms o de 305 ms. Los resultados mostraban que el IEE empleado durante la adquisición no afectaba a los TRs. En cambio, la utilización de un IEE corto durante la fase de prueba permitía detectar aprendizaje inconsciente, registrado como un efecto positivo de compatibilidad(AU)

The present research investigates the effect of interstimulus interval (ISI) during the acquisition and testing phases on associative learning with masked stimuli. 84 participants received repeated presentations of two stimulus sequences (S1A S2A and S1B S2B), S1 being a masked stimulus. S2 were imperative stimuli for a reaction time (RT) task. The ISI was 23 ms for the half of subjects and 305 ms for the other half. All participants were then tested with 14 presentations of compatible (S1A S2A and S1B S2B) and incompatible (S1A S2B and S1B S2A) stimulus sequences, using an ISI of 23 ms or 305 ms. The results showed that the ISI used during acquisition did not affected the RTs, but unconscious learning, detected as a positive compatibility effect, was obtained with a short ISI during the testing phase(AU)

Efecto de la duración de la extinción en la reinstauración selectiva de respuestas instrumentales en función de diferentes consecuencias / Effect of extinction duration on outcome-selective reinstatement of instrumental responses

Se diseñaron dos experimentos para evaluar la reinstauración selectiva de respuestas instrumentales asociadas a consecuencias diferentes (Experimento 1), y el efecto del número de sesiones de extinción en dicha reinstauración (Experimento 2). En el Experimento 1 se entrenó a dos grupos de ratas en tres fases. En la primera fase se condujeron dos sesiones diarias, en una la respuesta (R) 1 se asoció con la consecuencia (C) 1 y en la otra la R2 se asoció con la C2 para el Grupo Diferente, y para el Grupo Común se empleó la misma consecuencia para entrenar ambas respuestas. Posteriormente, en extinción, se descontinuó la entrega de las consecuencias. Finalmente, en la prueba se re-expuso a los sujetos a una de las consecuencias empleadas en la primera fase. En el Experimento 2 se empleó un procedimiento similar al del experimento previo, se entrenaron tres grupos (i.e. Común, Diferente C1 y Diferente C2) en cuatro fases secuenciales: Adquisición de R1, Adquisición de R2, Extinción y Prueba. En la fase de prueba se expuso a los grupos a alguna de las consecuencias empleadas durante el entrenamiento, después de 5 ó 10 sesiones de extinción. Los resultados mostraron reinstauración selectiva de respuestas en función de la consecuencia en ambos experimentos, aunque el Experimento 2 mostró reinstauración selectiva sólo cuando la prueba se realizó después de 5 sesiones de extinción, pero no cuando se emplearon 10 sesiones. Se discuten los resultados en términos de las propiedades que adquieren las consecuencias como estímulo discriminativo(AU)

Two-experiments were designed to analyze outcome-selective instrumental reinstatement (Experiment 1) and the effect of extinction on this sort of reinstatement (Experiment 2). In Experiment 1 two groups of rats were trained in three phases. In the first phase two-daily sessions were conducted. For the Different Group Response (R) 1 was reinforced with the (O) Outcome 1 in one of these sessions, and in the other session R2 was reinforced with the O2, while for the Same Group both responses were reinforced with the same outcome. In the extinction phase, outcomes were discontinued while both responses were available. Finally, in the test phase groups were re-exposed to one of the outcomes used in the first phase. In Experiment 2 a similar procedure to that described for Experiment 1 was used, three groups of rats (i.e. Same, Different O1 and Different O2) were trained in four sequential phases: Acquisition of R1, Acquisition of R2, Extinction and Test. In the test phase all groups were exposed to one of the outcomes used in either Acquisition phases, after 5 or 10 extinction sessions. Findings showed selective outcome reinstatement in both experiments, although Experiment 2 showed selective reinstatement only after 5 extinction sessions, but not after 10 extinction sessions. Results are discussed in terms of the properties of discriminative stimulus of the reinstatement outcome(AU)

Summation in predictive learning in children

Una cantidad considerable de investigación ha examinado las predicciones contrarias de los modelos elementalistas y configuracionales del aprendizaje. Uno de los métodos más simples para distinguir entre estos dos enfoques es la prueba de sumación, en la cual se examina la fuerza asociativa de un estímulo compuesto novedoso (AB) después del entrenamiento por separado de cada uno de sus elementos (A+ y B+). El enfoque configuracional predice que la fuerza asociativa del compuesto será aproximadamente el promedio de la fuerza asociativa de sus componentes, mientras que el enfoque elementalista predice que la fuerza del compuesto será mayor que la de cada uno de los elementos por separado. La prueba de sumación ha arrojado evidencia contradictoria en experimentos con animales así como también con humanos adultos. El propósito de la presente investigación fue examinar el fenómeno de sumatoria en el aprendizaje predictivo en niños de 5-9 años de edad. Los resultados arrojaron evidencia de sumatoria (AB mayor que A y B) luego un procedimiento de entrenamiento con “sumatoria simple” (A+ B+ y test con AB; Experimento 1, n=26), pero no evidencia de sumatoria luego de un procedimiento de “preservación de la inhibición condicionada” (A+B-ABseguido por B+ y test con AB; Experimento 2; n=26). En el Experimento 3 ambos efectos se observaron simultáneamente (n=14). Estos resultados son consistentes con hallazgos en condicionamiento clásico con animales y aprendizaje predictivo con adultos. Se discuten algunas alternativas teóricas dentro de los enfoques elementalista y configuracional(AU)

Considerable research has examined the contrasting predictions of configural and elemental associative accounts of learning. One of the simplest methods to distinguish between these approaches is the summation test, in which the associative strength of a novel compound (AB) made of two separately-trained cues (A+ and B+) is examined. The configural view predicts that the strength of the compound will approximate the average strength of its components, whereas the elemental approach predicts that the strength of the compound will be greater than the strength of either component. The summation test has lead to contradictory evidence in experiments with animals as well as with human adults. The purpose of this research was to examine summation in predictive learning of 5- 9 years old children. The results provided evidence of summation (i.e., AB greater than A and B) after training with a “simple summation” procedure (A+ B+ test with AB; Experiment 1, n=26); but no summation following a “preserved conditioned inhibition” procedure (i.e., A+ B- AB- followed by B+; and test with AB; Experiment 2, n=26). In Experiment 3, both effects were simultaneously observed (n=14). These results are consistent with reported findings in both Pavlovian conditioning with animals and predictive learning with adult humans. Theoretical alternatives within the elemental and configural approaches are discussed(AU)

Eficacia de la mnemotecnia de la palabra clave en personas adultas / Effi cacy of the keyword mnemonic method in adults

A través de dos experimentos intentamos averiguar la efectividad de la mnemotecnia de la palabra clave en personas adultas. En el Experimento 1 miramos si el recuerdo, inmediato y al cabo de un día, es superior en el grupo que utilizó la mnemotecnia de la palabra clave o en el grupo que utilizó el método de repetición. El grupo de personas que participó en la investigación tenía una media de edad de 59,35 años y tenía que aprender la traducción de una lista de 16 palabras latinas. Encontramos que el grupo que utilizó la mnemotecnia de la palabra clave, cuando ésta fue seleccionada por compañeros de las mismas características que los participantes, tuvo un recuerdo inmediato y al cabo de un día significativamente superior al grupo de repetición. En el Experimento 2 se utilizó una lista de 24 palabras latinas para que los participantes aprendiesen la traducción española mediante la mnemotecnia de la palabra clave reforzada con dibujos. También encontramos que el recuerdo inmediato y demorado del grupo de la mnemotecnia de la palabra clave fue significativamente superior al recuerdo del grupo que aprendió mediante el método de repetición (AU)

Two experiments were used to assess the efficacy of the keyword mnemonic method in adults. In Experiment 1, immediate and delayed recall (at a one day interval) were assessed by comparing the results obtained by a group of adults using the keyword mnemonic method in contrast to a group using the repetition method. The mean age of the sample under study was 59.35 years. Subjects were required to learn a list of 16 words translated from Latin into Spanish. Participants who used keyword mnemonics that had been devised by other experimental participants of the same characteristics, obtained significantly higher immediate and delayed recall scores than participants in the repetition method. In Experiment 2, other participants had to learn a list of 24 Latin words translated into Spanish by using the keyword mnemonic method reinforced with pictures. Immediate and delayed recall were significantly greater in the keyword mnemonic method group than in the repetition method group (AU)

Face-name association learning in early Alzheimer's disease: a comparison of learning methods and their underlying mechanisms.

This study compared the efficacy of five learning methods in the acquisition of face-name associations in early dementia of Alzheimer type (AD). The contribution of error production and implicit memory to the efficacy of each method was also examined. Fifteen participants with early AD and 15 matched controls were exposed to five learning methods: spaced retrieval, vanishing cues, errorless, and two trial-and-error methods, one with explicit and one with implicit memory task instructions. Under each method, participants had to learn a list of five face-name associations, followed by free recall, cued recall and recognition. Delayed recall was also assessed. For AD, results showed that all methods were efficient but there were no significant differences between them. The number of errors produced during the learning phases varied between the five methods but did not influence learning. There were no significant differences between implicit and explicit memory task instructions on test performances. For the control group, there were no differences between the five methods. Finally, no significant correlations were found between the performance of the AD participants in free recall and their cognitive profile, but generally, the best performers had better remaining episodic memory. Also, case study analyses showed that spaced retrieval was the method for which the greatest number of participants (four) obtained results as good as the controls. This study suggests that the five methods are effective for new learning of face-name associations in AD. It appears that early AD patients can learn, even in the context of error production and explicit memory conditions.

Learning nonlinearly separable categories by inference and classification.

Previous research suggests that learning categories by classifying new instances highlights information that is useful for discriminating between categories. In contrast, learning categories by making predictive inferences focuses learners on an abstract summary of each category (e.g., the prototype). To test this characterization of classification and inference learning further, the authors evaluated the two learning procedures with nonlinearly separable categories. In contrast to previous research involving cohesive, linearly separable categories, the authors found that it is more difficult to learn nonlinearly separable categories by making inferences about features than it is to learn them by classifying instances. This finding reflects that the prototype of a nonlinearly separable category does not provide a good summary of the category members. The results from this study suggest that having a cohesive category structure is more important for inference than it is for classification.

The fan effect: a tale of two theories.

This article addresses J. R. Anderson and L. M. Reder's (1999) account of the differential fan effect reported by G. A. Radvansky, D. H. Spieler, and R. T. Zacks (1993). The differential fan effect is the finding of greater interference with an increased number of associations under some conditions, but not others, in a within-subjects mixed-list recognition test. Anderson and Reder concluded that the differential fan effects can be adequately explained by assuming differences in the weights given to concepts in long-term memory. When a broader range of data is considered, this account is less well supported. Instead, it is better to assume that the organization of information into referential representations, such as situation models, has a meaningful influence on long-term memory retrieval.

Process, not representation: reply to Radvansky (1999).

The size of fan effects is determined by processes at retrieval, not by whether or not information is represented as situations. Evidence contradicts G. A. Radvansky's (1999) claim that time to retrieve information from a situation does not depend on the number of elements in the situation. Moreover, Radvansky's principles for ascribing situational models to experiments appear to be post hoc ways of redescribing the data. On the other hand, the evidence does support the Adaptive Control of Thought--Rational (ACT-R) assumption that participants can adjust their attentional weightings and so produce differential fan effects. Moreover, the ACT-R theory of the fan effect is consistent with many other findings.