Dual Systems Model Research Articles

Students' long-term memories from an ecology field excursion: Retelling a narrative as an interplay between implicit and explicit memories

This study aims to investigate the science content remembered by biology students 6 and 12 months after an ecology excursion. The students' memories were tested during a stimulated recall interview. The authors identified three different types of memories: recall, recognition and narratives. The dual memory system model of learning was used to connect recall to the explicit memory system (declarative knowledge), and recognition to the implicit memory system (tacit knowledge). The results show that the students' re-told narratives were scrambled and sometimes distorted. The students used small fragments to create their story and the next fragment of the story primarily depended on the antecedent unit. It is therefore suggested that in telling a narrative there is a constant interplay between the explicit (recall) and implicit (recognition) memory systems. The scientific terms (recall) were often replaced by everyday terms, indicating that the underlying meaning is not connected to the specific terms.

Individual differences in the development of sensation seeking and impulsivity during adolescence: Further evidence for a dual systems model.

Consistent with social neuroscience perspectives on adolescent development, previous cross-sectional research has found diverging mean age-related trends for sensation seeking and impulsivity during adolescence. The present study uses longitudinal data on 7,640 youth from the National Longitudinal Study of Youth Children and Young Adults, a nationally representative sample assessed biennially from 1994 to 2006. Latent growth curve models were used to investigate mean age-related changes in self-reports of impulsivity and sensation seeking from ages 12 to 24 years, as well individual differences in these changes. Three novel findings are reported. First, impulsivity and sensation seeking showed diverging patterns of longitudinal change at the population level. Second, there was substantial person-to-person variation in the magnitudes of developmental change in both impulsivity and sensation seeking, with some teenagers showing rapid changes as they matured and others maintaining relatively constant levels with age. Finally, the correlation between age-related changes in impulsivity and sensation seeking was modest and not significant. Together, these results constitute the first support for the dual systems model of adolescent development to derive from longitudinal behavioral data.

Representing serial action and perception

This article presents a review on the representational base of sequence learning in the serial reaction time task. The first part of the article addresses the major questions and challenges that underlie the debate on implicit and explicit learning. In the second part, the informational content that underlies sequence representations is reviewed. The latter issue has produced a rich and equivocal literature. A taxonomy illustrates that substantial support exists for associations between successive stimulus features, between successive response features, and between successive response-to-stimulus compounds. We suggest that sequence learning is not predetermined with respect to one particular type of information but, rather, develops according to an overall principle of activation contingent on task characteristics. Moreover, substantiating such an integrative approach is proposed by a synthesis with the dual-system model (Keele, Ivry, Mayr, Hazeltine, & Heuer, 2003).

Associative processes in intuitive judgment

Dual-system models of reasoning attribute errors of judgment to two failures: the automatic operations of a 'System 1' generate a faulty intuition, which the controlled operations of a 'System 2' fail to detect and correct. We identify System 1 with the automatic operations of associative memory and draw on research in the priming paradigm to describe how it operates. We explain how three features of associative memory--associative coherence, attribute substitution and processing fluency--give rise to major biases of intuitive judgment. Our article highlights both the ability of System 1 to create complex and skilled judgments and the role of the system as a source of judgment errors.

A dual systems model of adolescent risk‐taking

It has been hypothesized that reward-seeking and impulsivity develop along different timetables and have different neural underpinnings, and that the difference in their timetables helps account for heightened risk-taking during adolescence. In order to test these propositions, age differences in reward-seeking and impulsivity were examined in a socioeconomically and ethnically diverse sample of 935 individuals between the ages of 10 and 30, using self-report and behavioral measures of each construct. Consistent with predictions, age differences in reward-seeking follow a curvilinear pattern, increasing between preadolescence and mid-adolescence, and declining thereafter. In contrast, age differences in impulsivity follow a linear pattern, with impulsivity declining steadily from age 10 on. Heightened vulnerability to risk-taking in middle adolescence may be due to the combination of relatively higher inclinations to seek rewards and still maturing capacities for self-control.

Verbal Inflectional Morphology in L1 and L2 Spanish: A Frequency Effects Study Examining Storage Versus Composition

This study examines the storage vs. composition of Spanish inflected verbal forms in L1 and L2 speakers of Spanish. L2 participants were selected to have mid-to-advanced proficiency, high classroom experience, and low immersion experience, typical of medium-to-advanced foreign language learners. Participants were shown the infinitival forms of verbs from either Class I (the default class, which takes new verbs) or Classes II and III (non-default classes), and were asked to produce either first-person singular present-tense or imperfect forms, in separate tasks. In the present tense, the L1 speakers showed inflected-form frequency effects (i.e., higher frequency forms were produced faster, which is taken as a reflection of storage) for stem-changing (irregular) verb-forms from both Class I (e.g., pensar-pienso) and Classes II and III (e.g., perder-pierdo), as well as for non-stem-changing (regular) forms in Classes II/III (e.g., vender-vendo), in which the regular transformation does not appear to constitute a default. In contrast, Class I regulars (e.g., pescar-pesco), whose non-stem-changing transformation constitutes a default (e.g., it is applied to new verbs), showed no frequency effects. L2 speakers showed frequency effects for all four conditions (Classes I and II/III, regulars and irregulars). In the imperfect tense, the L1 speakers showed frequency effects for Class II/III (-ía-suffixed) but not Class I (-aba-suffixed) forms, even though both involve non-stem-change (regular) default transformations. The L2 speakers showed frequency effects for both types of forms. The pattern of results was not explained by a wide range of potentially confounding experimental and statistical factors, and does not appear to be compatible with single-mechanism models, which argue that all linguistic forms are learned and processed in associative memory. The findings are consistent with a dual-system view in which both verb class and regularity influence the storage vs. composition of inflected forms. Specifically, the data suggest that in L1, inflected verbal forms are stored (as evidenced by frequency effects) unless they are both from Class I and undergo non-stem-changing default transformations. In contrast the findings suggest that at least these L2 participants may store all inflected verb-forms. Taken together, the results support dual-system models of L1 and L2 processing in which, at least at mid-to-advanced L2 proficiency and lower levels of immersion experience, the processing of rule-governed forms may depend not on L1 combinatorial processes, but instead on memorized representations.

A dual system model of preferences under risk.

This article presents a dual system model (DSM) of decision making under risk and uncertainty according to which the value of a gamble is a combination of the values assigned to it independently by the affective and deliberative systems. On the basis of research on dual process theories and empirical research in Hsee and Rottenstreich (2004) and Rottenstreich and Hsee (2001) among others, the DSM incorporates (a) individual differences in disposition to rational versus emotional decision making, (b) the affective nature of outcomes, and (c) different task construals within its framework. The model has good descriptive validity and accounts for (a) violation of nontransparent stochastic dominance, (b) fourfold pattern of risk attitudes, (c) ambiguity aversion, (d) common consequence effect, (e) common ratio effect, (f) isolation effect, and (g) coalescing and event-splitting effects. The DSM is also used to make several novel predictions of conditions under which specific behavior patterns may or may not occur.

Link-based learning theory creates more problems than it solves

AbstractIn this response, we provide further clarification of the propositional approach to human associative learning. We explain why the empirical evidence favors the propositional approach over a dual-system approach and how the propositional approach is compatible with evolution and neuroscience. Finally, we point out aspects of the propositional approach that need further development and challenge proponents of dual-system models to specify the systems more clearly so that these models can be tested.

Interpreting dissociations between regular and irregular past-tense morphology: evidence from event-related potentials.

Neuropsychological dissociations between regular and irregular English past-tense morphology have been reported using a lexical decision task in which past-tense primes immediately precede present-tense targets. We present N400 event-related potential data from healthy participants using the same design. Both regular and irregular past-tense forms primed corresponding present-tense forms, but with a longer duration for irregular verbs. Phonological control conditions suggested that differences in formal overlap between prime and target contribute to, but do not account for, this difference, suggesting a link between irregular morphology and semantics. Further analysis dividing the irregular verbs into two categories (weak irregular and strong) revealed that priming for strong verbs was reliably stronger than that for weak irregular and regular verbs, which were statistically indistinguishable from one another. We argue that, although we observe a regular-irregular dissociation, the nature of this dissociation is more consistent with single- than with dual-system models of inflectional morphology.

Age differences in sensation seeking and impulsivity as indexed by behavior and self-report: Evidence for a dual systems model.

It has been hypothesized that sensation seeking and impulsivity, which are often conflated, in fact develop along different timetables and have different neural underpinnings, and that the difference in their timetables helps account for heightened risk taking during adolescence. In order to test these propositions, the authors examined age differences in sensation seeking and impulsivity in a socioeconomically and ethnically diverse sample of 935 individuals between the ages of 10 and 30, using self-report and behavioral measures of each construct. Consistent with the authors' predictions, age differences in sensation seeking, which are linked to pubertal maturation, follow a curvilinear pattern, with sensation seeking increasing between 10 and 15 and declining or remaining stable thereafter. In contrast, age differences in impulsivity, which are unrelated to puberty, follow a linear pattern, with impulsivity declining steadily from age 10 on. Heightened vulnerability to risk taking in middle adolescence may be due to the combination of relatively higher inclinations to seek excitement and relatively immature capacities for self-control that are typical of this period of development.

Partitioning the Domain of Social Inference: Dual Mode and Systems Models and Their Alternatives

Recent decades of theorizing about social inference phenomena have seen a variety of models that partitioned the underlying processes into two qualitatively distinct types whose specific nature was depicted differently in the different frameworks. The present article reviews major such partitioning efforts as well as their proposed alternatives, and discusses their unique features, their commonalities, and the conceptual and empirical issues that they raise.

TARGET ARTICLE: Duality Models in Social Psychology: From Dual Processes to Interacting Systems

Dual-system models explain social cognition and behavior as a joint function of 2 interconnected mental faculties, each operating according to different principles. In this article, we use the Reflective-Impulsive Model as an example and first describe 3 major advantages of dual-system models, i.e., their integrative power, their foundation in well-established constructs of cognition and neuroscience; and the ease with which they can explain the interplay of judgments and nonjudgmental processes. We then turn to current debates on the adequate number of systems, as well as on the role of freedom and consciousness. We conclude by stating that dual-system models are versatile tools to integrate existing findings and to stimulate new research in social cognition and beyond.

Event-related potentials demonstrate prolonged N400 priming effects for English irregular verbs

Evidence from event-related potentials has an important role to play in refining current models of inflectional morphology. Here, we present ERP data regarding the English past tense, using an immediate-priming design that frequently has been used in both healthy and neuropsychological populations (Tyler et al., 2002). The majority of extant ERP studies of inflectional morphology have adopted either priming designs based on lags of intervening items, which are argued to result in N400 effects specifically for regular morphology (Munte, Say, Clahsen, Schiltz, & Kutas, 1999), or designs employing morphological violations, which are argued to result in LAN-like effects specifically for overregularizations (Penke et al., 1997). The dissociations that have been found in the above work often have been used in support of dual-route models of the English past tense, in which regular past tenses are produced by affixation of the default (–ed) form, whereas irregular past tenses are stored in associative memory (Pinker & Ullman, 2002). Dual-system models have been challenged by connectionist theorists who argue that both regular and irregular morphology can be modeled within a single system that maps relationships between phonology, orthography, and semantics. Importantly, many such models specifically have been designed to account for behavioral data in immediate priming tasks (Plaut & Gonnerman, 2000). Thus, we wished to bridge these literatures with the ERP literature by using a more analogous design.

Phonological cross-linguistic effects in bilingual Spanish – English speaking children

Paradis (2001) posed the Interactional Dual Systems Model of language representation in which bilingual children possess two separate phonological systems that have mutual influence. Frequency of phonological cross-linguistic effects has been cited as evidence for determining phonological representation. The purpose of this study was to examine the frequency and types of phonological cross-linguistic effects that occur over time in bilingual children. Three female typically developing, bilingual Spanish – English speaking children, ages 5;0, 6;2, and 7;0 participated in the study. Single word, conversation, and narrative samples were examined for each child to determine the phonological makeup of each participant's speech. Two analyses were performed: (1) analysis of phonemic cross-linguistic effects and (2) analysis of syllabic cross-linguistic effects. There were eight occurrences of cross-linguistic effects across the three children. Overall, the frequency of cross-linguistic effects was low, supportin...

Private Arbeitslosenversicherungen – Risikoprämien statt Zwangsbeiträge

Abstract The German system of unemployment insurance has failed to prevent the rise of unemployment over the past decades. The authors suggest replacing the existing federal unemployment insurance by a dual-system model of private unemployment insurance that includes incentives on the side of employees as well as of employers to reduce unemployment. They calculate the statistic fundamentals of a dual system of private unemployment insurance, using data of the year 2000. It is shown how much the individual employee would have to invest for a variety of unemployment payments and for a variety of individual “real” risks. In addition, it is demonstrated that each individual can reduce his insurance premium by simply declaring a higher degree of regional, professional, or income-related mobility. On the employers’ side it is elaborated that, via autoregressive processes, employment increases, and that at the same time each employer reduces the rate of his firm’s unemployment tax.

The D2 receptor is critical in mediating opiate motivation only in opiate-dependent and withdrawn mice.

According to the dual systems model for opiate reward, dopamine mediates opiate motivation when an animal is in a deprived motivational state (i.e. opiate-dependent and in withdrawal) and not when an animal is in a nondeprived state (i.e. previously drug-naive). To determine the role of the D2 dopamine receptor subtype in mediating opiate motivation, we examined the behaviour of N5 congenic D2 receptor knockout mice and their wild-type siblings in opiate-naive and opiate-dependent and withdrawn place conditioning paradigms. Opiate-naive D2 receptor knockout mice demonstrated acquisition of morphine-conditioned place preference but failed to acquire place preference when conditioned in the deprived state. We propose that D2 receptor function is critical in mediating the motivational effects of opiates only when the animal is in an opiate-dependent and withdrawn motivational state. These findings also underscore the important influence of the genetic background to a given phenotype, as evidenced by the observation that increasing the allelic contribution from the 129/SvJ strain abolishes morphine place preference in C57BL/6 wild-type mice.

Fleshing out a dual-system solution

A prospective integration of evolutionary and other approaches to understanding rationality, as well as incorporation of individual difference concerns into the research agenda, are major contributions of Stanovich & West's analysis. This commentary focuses on issues of concern in detailing a dual-system or dual-process model of the sort they propose and using it as a basis for improving judgment.

Acceptability Ratings of Regular and Irregular Past-tense Forms: Evidence for a Dual-system Model of Language from Word Frequency and Phonological Neighbourhood Effects

What are the computational and representational bases of the mental lexicon of words, and of the rules of grammar which productively combine lexical forms into larger words, phrases and sentences? “Dual-system” theories posit that lexical forms with non-compositional (arbitrary) sound-meaning pairings are stored in memory, whereas compositional structures are subserved by a distinct rule-processing system. “Single-system” theories claim that lexicon and grammar are both subserved by a single associative memory. Investigations of English past tense may help to resolve this controversy. On the dual-system view, irregular past-tense forms (e.g. blowblew) are retrieved from memory, whereas regular past-tense forms (e.g. walk-walked) are produced by the application of an -ed -suffixation rule. On the single-system view, both types of past-tense forms are learned and computed in associative memory. To test these competing theories, acceptability ratings were elicited from native English-speaking adults for regular and irregular past-tense forms, and their stems, in sentence contexts. Partialling out stem ratings, ratings of irregular past-tense forms (blew) correlated with their frequencies and with measures of the number of similar sounding irregular verbs (threw, grew), whereas ratings of regular part-tense forms (walked) did not correlate with their frequencies or with measures of the number of similar-sounding regular verbs (stalked, balked). The results suggest that irregular past tenses are retrieved from associative memory, whereas regular past tenses are produced by a suffixation rule.

Microvascular regulation of muscle metabolism.

Nutrient and hormone delivery to skeletal muscle plays a major role in the regulation of metabolism of this tissue. Compromised perfusion, leading to the exclusion of single capillaries or groups of capillaries, can result from the inability of the cardiovascular system to maintain adequate total blood flow. Recent new data, however, indicate that nutrient delivery to skeletal muscle may not simply equate to total blood flow, but the partitioning between two circulatory systems, nutritive and non-nutritive, associated with each muscle. A number of hormones and neural mechanisms have now been identified that control the proportion of nutritive to non-nutritive flow. In addition, muscle metabolism and contractile performance have been shown to correlate with the extent of nutritive flow and inversely with non-nutritive flow, where the latter occurs in closely associated connective tissue. This review presents some of the evidence supporting the dual circulatory system model of muscle and the implications it may have in the management and treatment of patients subjected to shock, trauma, heart failure and long periods of immobilization.

Average waiting time profiles of uniform distributed queue dual bus system model

The Distributed Queue Dual Bus (DQDB) system consists of a linear arrangement of N nodes that communicate with each other using two contra-flowing buses. The nodes use an extremely simple protocol to send messages on these buses. This simple, but elegant, system has been found to be very challenging to analyze. We consider a simple and uniform abstraction of this model to highlight the fairness issues in terms of average waiting time. We introduce a new approximation method to analyze the performance of DQDB system in terms of the average waiting time of a node expressed as a function of its position. Our approach abstracts the intimate relationship between the load of the system and its fairness characteristics, and explains all basic behavior profiles of DQDB observed in previous simulation. For the uniform DQDB with equal distance between adjacent nodes, we show that the system operates under three basic behavior profiles and a finite number of their combinations that depend on the load of the network. Consequently, the system is not fair at any load in terms of the average waiting times. We also show that the main theme of the analysis carries over to the general (nonuniform) DQDB. By suitably choosing the inter-node distances, the DQDB can be made fair around some loads, but such system will become unfair as the load changes. In the vicinity of a critical load, the uniform network runs into a state of instability, where its behavior fluctuates from one extreme to the other with small load variations. Our analysis is supported by simulation results. >